Copyright © Future Technology Devices International Limited 1
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Neither the whole nor any part of the information contained in, or the product described in this manual, may be adapted or re produced
in any material or electronic form without the prior written consent of the copyright holder. This product and its documentation are
supplied on an as-is basis and no warranty as to their suitability for any particular purpose is either made or implied. Future Technology
Devices International Ltd will not accept any claim for damages howsoever arising as a result of use or failure of this product. Your
statutory rights are not affected. This product or any variant of it is not intended for use in any medical appliance, device or system in
which the failure of the product might reasonably be expected to result in personal injury. This document provides preliminary
information that may be subject to change without notice. No freedom to use patents or other intellectual property rights is implied by
the publication of this document. Future Technology Devices International Ltd, Unit 1, 2 Seaward Place, Centurion Business Park, Glasgow
G41 1HH United Kingdom. Scotland Registered Company Number: SC136640
Future Technology Devices
International Ltd.
FT232R USB UART IC
Datasheet
The FT232R is a USB to serial UART interface
with the following advanced features:
Single chip USB to asynchronous serial data
transfer interface.
Entire USB protocol handled on the chip. No
USB specific firmware programming required.
Fully integrated 1024 bit EEPROM storing
device descriptors and CBUS I/O configuration.
Fully integrated USB termination resistors.
Fully integrated clock generation with no
external crystal required plus optional clock
output selection enabling a glue-less interface
to external MCU or FPGA.
Data transfer rates from 300 baud to 3 Mbaud
(RS422, RS485, RS232) at TTL levels.
128 byte receive buffer and 256 byte transmit
buffer utilising buffer smoothing technology to
allow for high data throughput.
FTDI’s royalty-free Virtual Com Port (VCP) and
Direct (D2XX) drivers eliminate the
requirement for USB driver development in
most cases.
Unique USB FTDIChip-ID™ feature.
Configurable CBUS I/O pins.
Transmit and receive LED drive signals.
UART interface support for 7 or 8 data bits, 1
or 2 stop bits and odd / even / mark / space /
no parity
FIFO receives and transmits buffers for high
data throughput.
Synchronous and asynchronous bit bang
interface options with RD# and WR# strobes.
Device supplied pre-programmed with unique
USB serial number.
Supports bus powered, self-powered and high-
power bus powered USB configurations.
Integrated +3.3V level converter for USB I/O.
Integrated level converter on UART and CBUS
for interfacing to between +1.8V and +5V
logic.
True 5V/3.3V/2.8V/1.8V CMOS drive output
and TTL input.
Configurable I/O pin output drive strength.
Integrated power-on-reset circuit.
Fully integrated AVCC supply filtering - no
external filtering required.
UART signal inversion option.
+3.3V (using external oscillator) to +5.25V
(internal oscillator) Single Supply Operation.
Low operating and USB suspend current.
Low USB bandwidth consumption.
UHCI/OHCI/EHCI host controller compatible.
USB 2.0 Full Speed compatible.
-40°C to 85°C extended operating temperature
range.
Available in compact Pb-free 28 Pin SSOP and
QFN-32 packages (both RoHS compliant).
Copyright © Future Technology Devices International Limited 2
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
1 Typical Applications
USB to RS232/RS422/RS485 Converters
Upgrading Legacy Peripherals to USB
Cellular and Cordless Phone USB data transfer
cables and interfaces
Interfacing MCU/PLD/FPGA based designs to
USB
USB Audio and Low Bandwidth Video data
transfer
PDA to USB data transfer
USB Smart Card Readers
USB Instrumentation
USB Industrial Control
USB MP3 Player Interface
USB FLASH Card Reader and Writers
Set Top Box PC - USB interface
USB Digital Camera Interface
USB Hardware Modems
USB Wireless Modems
USB Bar Code Readers
USB Software and Hardware Encryption
Dongles
1.1 Driver Support
Royalty free VIRTUAL COM PORT
(VCP) DRIVERS for...
Windows 10 32,64-bit
Windows 8/8.1 32,64-bit
Windows 7 32,64-bit
Windows Vista and Vista 64-bit
Windows XP and XP 64-bit
Windows 98, 98SE, ME, 2000, Server 2003, XP,
Server 2008 and server 2012 R2
Windows XP Embedded
Windows CE 4.2, 5.0 and 6.0
Mac OS 8/9, OS-X
Linux 2.4 and greater
Royalty free D2XX Direct Drivers
(USB Drivers + DLL S/W Interface)
Windows 10 32,64-bit
Windows 8/8.1 32,64-bit
Windows 7 32,64-bit
Windows Vista and Vista 64-bit
Windows XP and XP 64-bit
Windows 98, 98SE, ME, 2000, Server 2003, XP,
Server 2008 and server 2012 R2
Windows XP Embedded
Windows CE 4.2, 5.0 and 6.0
Linux 2.4 and greater
Android(J2xx)
The drivers listed above are all available to download for free from FTDI website (www.ftdichip.com).
Various 3rd party drivers are also available for other operating systems - see FTDI website
(www.ftdichip.com) for details.
For driver installation, please refer to http://www.ftdichip.com/Documents/InstallGuides.htm
Copyright © Future Technology Devices International Limited 3
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
1.2 Part Numbers
Part Number
Package
FT232RQ-xxxx
32 Pin QFN
FT232RL-xxxx
28 Pin SSOP
Note: Packing codes for xxxx is:
- Reel: Taped and Reel, (SSOP is 2,000pcs per reel, QFN is 6,000pcs per reel).
- Tube: Tube packing, 47pcs per tube (SSOP only)
- Tray: Tray packing, 490pcs per tray (QFN only)
For example: FT232RQ-Reel is 6,000pcs taped and reel packing
1.3 USB Compliant
The FT232R is fully compliant with the USB 2.0 specification and has been given the USB-IF Test-ID (TID)
40680004 (Rev B) and 40770018 (Rev C).
Copyright © Future Technology Devices International Limited 4
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
2 FT232R Block Diagram
Figure 2.1 FT232R Block Diagram
For a description of each function please refer to Section 4.
Copyright © Future Technology Devices International Limited 5
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Table of Contents
1 Typical Applications ....................................................... 2
1.1 Driver Support ........................................................................... 2
1.2 Part Numbers ............................................................................. 3
1.3 USB Compliant ........................................................................... 3
2 FT232R Block Diagram .................................................. 4
3 Device Pin Out and Signal Description ........................... 7
3.1 28-LD SSOP Package .................................................................. 7
3.2 SSOP Package Pin Out Description ............................................. 7
3.3 QFN-32 Package ...................................................................... 10
3.4 QFN-32 Package Signal Description ......................................... 10
3.5 CBUS Signal Options ................................................................ 12
4 Function Description ................................................... 14
4.1 Key Features ............................................................................ 14
4.2 Functional Block Descriptions .................................................. 15
5 Devices Characteristics and Ratings ............................ 17
5.1 Absolute Maximum Ratings ...................................................... 17
5.2 DC Characteristics .................................................................... 18
5.3 EEPROM Reliability Characteristics .......................................... 21
5.4 Internal Clock Characteristics .................................................. 21
5.5 Thermal Characteristics ........................................................... 22
6 USB Power Configurations ........................................... 23
6.1 USB Bus Powered Configuration ............................................. 23
6.2 Self Powered Configuration ..................................................... 24
6.3 USB Bus Powered with Power Switching Configuration ........... 25
6.4 USB Bus Powered with Selectable External Logic Supply ......... 26
7 Application Examples .................................................. 28
7.1 USB to RS232 Converter .......................................................... 28
7.2 USB to RS485 Converter .......................................................... 29
7.3 USB to RS422 Converter .......................................................... 30
7.4 USB to MCU UART Interface ..................................................... 31
Copyright © Future Technology Devices International Limited 6
FT232R USB UART IC Datasheet
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Document No.: FT_000053 Clearance No.: FTDI# 38
7.5 LED Interface ........................................................................... 32
7.6 Using the External Oscillator .................................................... 33
8 Internal EEPROM Configuration ................................... 34
9 Package Parameters .................................................... 36
9.1 SSOP-28 Package Dimensions ................................................. 36
9.2 QFN-32 Package Dimensions ................................................... 37
9.3 QFN-32 Package Typical Pad Layout ........................................ 38
9.4 QFN-32 Package Typical Solder Paste Diagram ........................ 38
9.5 Solder Reflow Profile ............................................................... 39
10 Alternative Parts ......................................................... 41
11 Contact Information .................................................... 42
Appendix A – References ................................................... 43
Document References ...................................................................... 43
Acronyms and Abbreviations ............................................................ 43
Appendix B – List of Figures and Tables ............................. 44
List of Figures .................................................................................. 44
List of Tables .................................................................................... 44
Appendix C – Revision History ........................................... 46
Copyright © Future Technology Devices International Limited 7
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
3 Device Pin Out and Signal Description
3.1 28-LD SSOP Package
Figure 3.1 SSOP Package Pin Out and Schematic Symbol
3.2 SSOP Package Pin Out Description
Note: The convention used throughout this document for active low signals is the signal name followed
by#
Pin No.
Name
Type
Description
15
USBDP
I/O
USB Data Signal Plus, incorporating internal series resistor and 1.5kΩ
pull up resistor to 3.3V.
16
USBDM
I/O
USB Data Signal Minus, incorporating internal series resistor.
Table 3.1 USB Interface Group
Pin No.
Name
Type
Description
4
VCCIO
PWR
+1.8V to +5.25V supply to the UART Interface and CBUS group pins
(1...3, 5, 6, 9...14, 22, 23). In USB bus powered designs connect this pin
to 3V3OUT pin to drive out at +3.3V levels, or connect to VCC to drive
out at 5V CMOS level. This pin can also be supplied with an external
+1.8V to +2.8V supply in order to drive outputs at lower levels. It should
be noted that in this case this supply should originate from the same
source as the supply to VCC. This means that in bus powered designs a
regulator which is supplied by the +5V on the USB bus should be used.
USBDP
USBDM
3V3OUT
GND
RESET#
VCC
GND
NC
AGND
TEST
OSCI
OSCO
CBUS1
CBUS0
TXD
RTS#
RXD
DTR#
VCCIO
RI#
GND
NC
DSR#
DCD#
CTS#
CBUS4
CBUS2
CBUS3
1
14 15
28
FT232RL
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
25 718 21 26
3V3OUT
VCCIO
4
17
NC
RESET#
NC
24
19
8
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
1
5
3
11
2
9
10
6
CBUS0
CBUS3
CBUS2
CBUS1
23
22
13
14
20
16
15 USBDP
USBDM
VCC
OSCI
27
OSCO
28
CBUS4 12
FTDI
FT232RL
YYXX-A
XXXXXXXXXXXX
Copyright © Future Technology Devices International Limited 8
FT232R USB UART IC Datasheet
Version 2.14
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Pin No.
Name
Type
Description
7, 18,
21
GND
PWR
Device ground supply pins
17
3V3OUT
Output
+3.3V output from integrated LDO regulator. This pin should be
decoupled to ground using a 100nF capacitor. The main use of this pin is
to provide the internal +3.3V supply to the USB transceiver cell and the
internal 1.5kΩ pull up resistor on USBDP. Up to 50mA can be drawn from
this pin to power external logic if required. This pin can also be used to
supply the VCCIO pin.
20
VCC
PWR
+3.3V to +5.25V supply to the device core. (see Note 1)
25
AGND
PWR
Device analogue ground supply for internal clock multiplier
Table 3.2 Power and Ground Group
Pin No.
Name
Type
Description
8, 24
NC
NC
No internal connection
19
RESET#
Input
Active low reset pin. This can be used by an external device to reset the
FT232R. If not required can be left unconnected, or pulled up to VCC.
26
TEST
Input
Puts the device into IC test mode. Must be tied to GND for normal
operation, otherwise the device will appear to fail.
27
OSCI
Input
Input 12MHz Oscillator Cell. Optional – Can be left unconnected for
normal operation. (see Note 2)
28
OSCO
Output
Output from 12MHZ Oscillator Cell. Optional – Can be left unconnected
for normal operation if internal Oscillator is used. (see Note 2)
Table 3.3 Miscellaneous Signal Group
Pin No.
Name
Type
Description
1
TXD
Output
Transmit Asynchronous Data Output.
2
DTR#
Output
Data Terminal Ready Control Output / Handshake Signal.
3
RTS#
Output
Request to Send Control Output / Handshake Signal.
5
RXD
Input
Receiving Asynchronous Data Input.
6
RI#
Input
Ring Indicator Control Input. When remote wake up is enabled in the
internal EEPROM taking RI# low (20ms active low pulse) can be used to
resume the PC USB host controller from suspend.
9
DSR#
Input
Data Set Ready Control Input / Handshake Signal.
10
DCD#
Input
Data Carrier Detect Control Input.
11
CTS#
Input
Clear To Send Control Input / Handshake Signal.
Copyright © Future Technology Devices International Limited 9
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Pin No.
Name
Type
Description
12
CBUS4
I/O
Configurable CBUS output only Pin. Function of this pin is configured in
the device internal EEPROM. Factory default configuration is SLEEP#. See
CBUS Signal Options, Table 3.9.
13
CBUS2
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device internal EEPROM. Factory default configuration is TXDEN. See
CBUS Signal Options, Table 3.9.
14
CBUS3
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device internal EEPROM. Factory default configuration is PWREN#. See
CBUS Signal Options, Table 3.9. PWREN# should be used with a 10kΩ
resistor pull up.
22
CBUS1
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device internal EEPROM. Factory default configuration is RXLED#. See
CBUS Signal Options, Table 3.9.
23
CBUS0
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the
device internal EEPROM. Factory default configuration is TXLED#. See
CBUS Signal Options, Table 3.9.
Table 3.4 UART Interface and CUSB Group (see note 3)
Notes:
1. The minimum operating voltage VCC must be +4.0V (could use VBUS=+5V) when using the
internal clock generator. Operation at +3.3V is possible using an external crystal oscillator.
2. For details on how to use an external crystal, ceramic resonator, or oscillator with the FT232R,
please refer Section 7.6
3. When used in Input Mode, the input pins are pulled to VCCIO via internal 200kΩ resistors. These
pins can be programmed to gently pull low during USB suspend (PWREN# = “1”) by setting an
option in the internal EEPROM.
Copyright © Future Technology Devices International Limited 10
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
3.3 QFN-32 Package
Figure 3.2 QFN-32 Package Pin Out and schematic symbol
3.4 QFN-32 Package Signal Description
Pin
No.
Name
Type
Description
14
USBDP
I/O
USB Data Signal Plus, incorporating internal series resistor and 1.5kΩ pull
up resistor to +3.3V.
15
USBDM
I/O
USB Data Signal Minus, incorporating internal series resistor.
Table 3.5 USB Interface Group
Pin No.
Name
Type
Description
1
VCCIO
PWR
+1.8V to +5.25V supply for the UART Interface and CBUS group pins (2,3,
6,7,8,9,10,11,21,22,30,31,32). In USB bus powered designs connect this
pin to 3V3OUT to drive out at +3.3V levels, or connect to VCC to drive out
FT232RQ
32 25
24
17
169
8
1
YYXX-A
18
9
1
2
3
4
5
6
7
8
10111213141516
17
19
20
21
22
23
24
25 26 27 28 29 30 31 32
USBDP
USBDM
3V3OUT
RESET#
VCC
NC
AGND
TEST
OSCI
OSCO
CBUS1
CBUS0
TXD
RTS#
RXD
DTR#
VCCIO
RI#
GND
NC
DSR#
DCD#
CTS#
CBUS4
CBUS2
CBUS3
GND
GND
NC
NC
NC
NC
I
FT232RQ
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
24 417 20 26
3V3OUT
VCCIO
1
16
NC
RESET#
NC
23
18
13
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
30
2
32
8
31
6
7
3
CBUS0
CBUS3
CBUS2
CBUS1
22
21
10
11
19
15
14 USBDP
USBDM
VCC
OSCI
27
OSCO
28
CBUS4 9
NC
12 NC
5
NC
29 NC
25
FTD
XXXXXXX
Copyright © Future Technology Devices International Limited 11
FT232R USB UART IC Datasheet
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Pin No.
Name
Type
Description
at +5V CMOS level. This pin can also be supplied with an external +1.8V
to +2.8V supply in order to drive out at lower levels. It should be noted
that in this case this supply should originate from the same source as the
supply to VCC. This means that in bus powered designs a regulator which
is supplied by the +5V on the USB bus should be used.
4, 17,
20
GND
PWR
Device ground supply pins.
16
3V3OUT
Output
+3.3V output from integrated LDO regulator. This pin should be decoupled
to ground using a 100nF capacitor. The purpose of this output is to provide
the internal +3.3V supply to the USB transceiver cell and the internal
1.5kΩ pull up resistor on USBDP. Up to 50mA can be drawn from this pin
to power external logic if required. This pin can also be used to supply the
VCCIO pin.
19
VCC
PWR
+3.3V to +5.25V supply to the device core. (See Note 1).
24
AGND
PWR
Device analogue ground supply for internal clock multiplier.
Table 3.6 Power and Ground Group
Pin No.
Name
Type
Description
5, 12,
13, 23,
25, 29
NC
NC
No internal connection. Do not connect.
18
RESET#
Input
Active low reset. Can be used by an external device to reset the FT232R. If
not required can be left unconnected, or pulled up to VCC.
26
TEST
Input
Puts the device into IC test mode. Must be tied to GND for normal
operation, otherwise the device will appear to fail.
27
OSCI
Input
Input 12MHz Oscillator Cell. Optional – Can be left unconnected for normal
operation. (See Note 2).
28
OSCO
Output
Output from 12MHZ Oscillator Cell. Optional – Can be left unconnected for
normal operation if internal Oscillator is used. (See Note 2).
Table 3.7 Miscellaneous Signal Group
Pin
No.
Name
Type
Description
30
TXD
Output
Transmit Asynchronous Data Output.
31
DTR#
Output
Data Terminal Ready Control Output / Handshake Signal.
32
RTS#
Output
Request to Send Control Output / Handshake Signal.
2
RXD
Input
Receiving Asynchronous Data Input.
3
RI#
Input
Ring Indicator Control Input. When remote wake up is enabled in the internal
EEPROM taking RI# low (20ms active low pulse) can be used to resume the
Copyright © Future Technology Devices International Limited 12
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Pin
No.
Name
Type
Description
PC USB host controller from suspend.
6
DSR#
Input
Data Set Ready Control Input / Handshake Signal.
7
DCD#
Input
Data Carrier Detect Control Input.
8
CTS#
Input
Clear To Send Control Input / Handshake Signal.
9
CBUS4
I/O
Configurable CBUS output only Pin. Function of this pin is configured in the
device internal EEPROM. Factory default configuration is SLEEP#. See CBUS
Signal Options, Table 3.9.
10
CBUS2
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the device
internal EEPROM. Factory default configuration is TXDEN. See CBUS Signal
Options, Table 3.9.
11
CBUS3
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the device
internal EEPROM. Factory default configuration is PWREN#. See CBUS Signal
Options, Table 3.9. PWREN# should be used with a 10kΩ resistor pull up.
21
CBUS1
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the device
internal EEPROM. Factory default configuration is RXLED#. See CBUS Signal
Options, Table 3.9.
22
CBUS0
I/O
Configurable CBUS I/O Pin. Function of this pin is configured in the device
internal EEPROM. Factory default configuration is TXLED#. See CBUS Signal
Options, Table 3.9.
Table 3.8 UART Interface and CBUS Group (see note 3)
Notes:
1. The minimum operating voltage VCC must be +4.0V (could use VBUS=+5V) when using the
internal clock generator. Operation at +3.3V is possible using an external crystal oscillator.
2. For details on how to use an external crystal, ceramic resonator, or oscillator with the FT232R,
please refer to Section 7.6.
3. When used in Input Mode, the input pins are pulled to VCCIO via internal 200kΩ resistors. These
pins can be programmed to gently pull low during USB suspend (PWREN# = “1”) by setting an
option in the internal EEPROM.
3.5 CBUS Signal Options
The following options can be configured on the CBUS I/O pins. CBUS signal options are common to both
package versions of the FT232R. These options can be configured in the internal EEPROM using the
software utility FT_PROG, which can be downloaded from the FTDI Utilities (www.ftdichip.com). The
default configuration is described in Section 8.
CBUS Signal
Option
Available On CBUS Pin
Description
TXDEN
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
Enable transmit data for RS485
PWREN#
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
Output is low after the device has been configured
by USB, then high during USB suspending mode.
Copyright © Future Technology Devices International Limited 13
FT232R USB UART IC Datasheet
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CBUS Signal
Option
Available On CBUS Pin
Description
This output can be used to control power to
external logic P-Channel logic level MOSFET switch.
Enable the interface pull-down option when using
the PWREN# in this way.*
TXLED#
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
Transmit data LED drive: Data from USB Host to
FT232R. Pulses low when transmitting data via USB.
See Section 7.5 for more details.
RXLED#
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
Receive data LED drive: Data from FT232R to USB
Host. Pulses low when receiving data via USB. See
Section 7.5 for more details.
TX&RXLED#
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
LED drive – pulses low when transmitting or
receiving data via USB. See Section 7.5 for more
details.
SLEEP#
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
Goes low during USB suspend mode. Typically used
to power down an external TTL to RS232 level
converter IC in USB to RS232 converter designs.
CLK48
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
48MHz ±0.7% Clock output. **
CLK24
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
24 MHz Clock output. **
CLK12
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
12 MHz Clock output. **
CLK6
CBUS0, CBUS1, CBUS2,
CBUS3, CBUS4
6 MHz ±0.7% Clock output. **
CBitBangI/O
CBUS0, CBUS1, CBUS2,
CBUS3
CBUS bit bang mode option. Allows up to 4 of the
CBUS pins to be used as general purpose I/O.
Configured individually for CBUS0, CBUS1, CBUS2
and CBUS3 in the internal EEPROM. A separate
application note, AN232R-01, available from FTDI
website (www.ftdichip.com) describes in more detail
how to use CBUS bit bang mode.
BitBangWRn
CBUS0, CBUS1
Synchronous and asynchronous bit bang mode WR#
strobe output.
BitBangRDn
CBUS0, CBUS1, CBUS2,
CBUS3
Synchronous and asynchronous bit bang mode RD#
strobe output.
Table 3.9 CBUS Configuration Control
* PWREN# must be used with a 10kΩ resistor pull up.
**When in USB suspend mode the outputs clocks are also suspended.
Copyright © Future Technology Devices International Limited 14
FT232R USB UART IC Datasheet
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4 Function Description
The FT232R is a USB to serial UART interface device which simplifies USB to serial designs and reduces
external component count by fully integrating an external EEPROM, USB termination resistors and an
integrated clock circuit which requires no external crystal, into the device. It has been designed to
operate efficiently with a USB host controller by using as little as possible of the total USB bandwidth
available.
4.1 Key Features
Functional Integration. Fully integrated EEPROM, USB termination resistors, clock generation, AVCC
filtering, POR and LDO regulator.
Configurable CBUS I/O Pin Options. The fully integrated EEPROM allows configuration of the Control
Bus (CBUS) functionality, signal inversion and drive strength selection. There are 5 configurable CBUS
I/O pins. These configurable options are
1. TXDEN - transmit enable for RS485 designs.
2. PWREN# - Power control for high power, bus powered designs.
3. TXLED# - for pulsing an LED upon transmission of data.
4. RXLED# - for pulsing an LED upon receiving data.
5. TX&RXLED# - which will pulse an LED upon transmission OR reception of data.
6. SLEEP# - indicates that the device going into USB suspend mode.
7. CLK48 / CLK24 / CLK12 / CLK6 - 48MHz, 24MHz, 12MHz, and 6MHz clock output signal
options.
8. BitBangWRn / BitBangRDn - Synchronous and asynchronous bit bang mode WR# / RD#
strobe outputs
The CBUS pins can also be individually configured as GPIO pins, similar to asynchronous bit bang mode.
It is possible to use this mode while the UART interface is being used, thus providing up to 4 general
purpose I/O pins which are available during normal operation. An application note, AN232R-01, available
from FTDI website (www.ftdichip.com) describes this feature.
The CBUS lines can be configured with any one of these output options by setting bits in the internal
EEPROM. The device is supplied with the most commonly used pin definitions pre-programmed - see
Section 8 for details.
Asynchronous Bit Bang Mode with RD# and WR# Strobes. The FT232R supports FTDI’s previous
chip generation bit-bang mode. In bit-bang mode, the eight UART lines can be switched from the regular
interface mode to an 8-bit general purpose I/O port. Data packets can be sent to the device and they will
be sequentially sent to the interface at a rate controlled by an internal timer (equivalent to the baud rate
pre-scaler). With the FT232R device this mode has been enhanced by outputting the internal RD# and
WR# strobes signals which can be used to allow external logic to be clocked by accesses to the bit-bang
I/O bus. This option will be described more fully in a separate application note available from FTDI
website (www.ftdichip.com).
Synchronous Bit Bang Mode. The FT232R supports synchronous bit bang mode. This mode differs from
asynchronous bit bang mode in that the interface pins are only read when the device is written to. This
makes it easier for the controlling program to measure the response to an output stimulus as the data
returned is synchronous to the output data. An application note, AN232R-01, available from FTDI website
(www.ftdichip.com) describes this feature.
FTDIChip-ID™. The FT232R also includes the new FTDIChip-ID™ security dongle feature. This
FTDIChip-ID™ feature allows a unique number to be burnt into each device during manufacture. This
number cannot be reprogrammed. This number is only readable over USB and forms a basis of a security
dongle which can be used to protect any customer application software being copied. This allows the
possibility of using the FT232R in a dongle for software licensing. Further to this, a renewable license
scheme can be implemented based on the FTDIChip-ID™ number when encrypted with other information.
This encrypted number can be stored in the user area of the FT232R internal EEPROM, and can be
decrypted, then compared with the protected FTDIChip-ID™ to verify that a license is valid. Web based
applications can be used to maintain product licensing this way. An application note, AN232R-02,
available from FTDI website (www.ftdichip.com) describes this feature.
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The FT232R is capable of operating at a voltage supply between +3.3V and +5V with a nominal
operational mode current of 15mA and a nominal USB suspend mode current of 70µA. This allows greater
margin for peripheral designs to meet the USB suspend mode current limit of 2.5mA. An integrated level
converter within the UART interface allows the FT232R to interface to UART logic running at +1.8V, 2.5V,
+3.3V or +5V.
4.2 Functional Block Descriptions
The following paragraphs detail each function within the FT232R. Please refer to the block diagram shown
in Figure 2.1
Internal EEPROM. The internal EEPROM in the FT232R is used to store USB Vendor ID (VID), Product ID
(PID), device serial number, product description string and various other USB configuration descriptors.
The internal EEPROM is also used to configure the CBUS pin functions. The FT232R is supplied with the
internal EEPROM pre-programmed as described in Section 8. A user area of the internal EEPROM is
available to system designers to allow storing additional data. The internal EEPROM descriptors can be
programmed in circuit, over USB without any additional voltage requirement. It can be programmed
using the FTDI utility software called FT_PROG, which can be downloaded from FTDI Utilities on the FTDI
website (www.ftdichip.com).
+3.3V LDO Regulator. The +3.3V LDO regulator generates the +3.3V reference voltage for driving the
USB transceiver cell output buffers. It requires an external decoupling capacitor to be attached to the
3V3OUT regulator output pin. It also provides +3.3V power to the 1.5kΩ internal pull up resistor on
USBDP. The main function of the LDO is to power the USB Transceiver and the Reset Generator Cells
rather than to power external logic. However, it can be used to supply external circuitry requiring a
+3.3V nominal supply with a maximum current of 50mA.
USB Transceiver. The USB Transceiver Cell provides the USB 1.1 / USB 2.0 full-speed physical interface
to the USB cable. The output drivers provide +3.3V level slew rate control signalling, whilst a differential
input receiver and two single ended input receivers provide USB data in, Single-Ended-0 (SE0) and USB
reset detection conditions respectfully. This function also incorporates the internal USB series termination
resistors on the USB data lines and a 1.5kΩ pull up resistor on USBDP.
USB DPLL. The USB DPLL cell locks on to the incoming NRZI USB data and generates recovered clock
and data signals for the Serial Interface Engine (SIE) block.
Internal 12MHz Oscillator - The Internal 12MHz Oscillator cell generates a 12MHz reference clock. This
provides an input to the x4 Clock Multiplier function. The 12MHz Oscillator is also used as the reference
clock for the SIE, USB Protocol Engine and UART FIFO controller blocks.
Clock Multiplier / Divider. The Clock Multiplier / Divider takes the 12MHz input from the Internal
Oscillator function and generates the 48MHz, 24MHz, 12MHz and 6MHz reference clock signals. The 48Mz
clock reference is used by the USB DPLL and the Baud Rate Generator blocks.
Serial Interface Engine (SIE). The Serial Interface Engine (SIE) block performs the parallel to serial
and serial to parallel conversion of the USB data. In accordance with the USB 2.0 specification, it
performs bit stuffing/un-stuffing and CRC5/CRC16 generation. It also checks the CRC on the USB data
stream.
USB Protocol Engine. The USB Protocol Engine manages the data stream from the device USB control
endpoint. It handles the low level USB protocol requests generated by the USB host controller and the
commands for controlling the functional parameters of the UART in accordance with the USB 2.0
specification chapter 9.
FIFO RX Buffer (128 bytes). Data sent from the USB host controller to the UART via the USB data OUT
endpoint is stored in the FIFO RX (receive) buffer. Data is removed from the buffer to the UART transmit
register under control of the UART FIFO controller. (Rx relative to the USB interface).
FIFO TX Buffer (256 bytes). Data from the UART receive register is stored in the TX buffer. The USB
host controller removes data from the FIFO TX Buffer by sending a USB request for data from the device
data IN endpoint. (Tx relative to the USB interface).
UART FIFO Controller. The UART FIFO controller handles the transfer of data between the FIFO RX and
TX buffers and the UART transmit and receive registers.
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UART Controller with Programmable Signal Inversion and High Drive. Together with the UART
FIFO Controller the UART Controller handles the transfer of data between the FIFO RX and FIFO TX
buffers and the UART transmit and receive registers. It performs asynchronous 7 or 8 bit parallel to serial
and serial to parallel conversion of the data on the RS232 (or RS422 or RS485) interface.
Control signals supported by UART mode include RTS, CTS, DSR, DTR, DCD and RI. The UART Controller
also provides a transmitter enable control signal pin option (TXDEN) to assist with interfacing to RS485
transceivers. RTS/CTS, DSR/DTR and XON / XOFF handshaking options are also supported. Handshaking
is handled in hardware to ensure fast response times. The UART interface also supports the RS232
BREAK setting and detection conditions.
Additionally, the UART signals can each be individually inverted and have a configurable high drive
strength capability. Both these features are configurable in the EEPROM.
Baud Rate Generator - The Baud Rate Generator provides a 16x clock input to the UART Controller
from the 48MHz reference clock. It consists of a 14 bit pre-scaler and 3 register bits which provide fine
tuning of the baud rate (used to divide by a number plus a fraction or “sub-integer”). This determines the
baud rate of the UART, which is programmable from 183 baud to 3 Mbaud.
The FT232R supports all standard baud rates and non-standard baud rates from 183 Baud up to 3
Mbaud. Achievable non-standard baud rates are calculated as follows -
Baud Rate = 3000000 / (n + x)
Where ‘n’ can be any integer between 2 and 16,384 ( = 214 ) and ‘x’ can be a sub-integer of the value 0,
0.125, 0.25, 0.375, 0.5, 0.625, 0.75, or 0.875. When n = 1, x = 0, i.e. baud rate divisors with values
between 1 and 2 are not possible.
This gives achievable baud rates in the range 183.1 baud to 3,000,000 baud. When a non-standard baud
rate is required simply pass the required baud rate value to the driver as normal, and the FTDI driver will
calculate the required divisor, and set the baud rate. See FTDI application note AN232B-05 on the FTDI
website (www.ftdichip.com) for more details.
RESET Generator - The integrated Reset Generator Cell provides a reliable power-on reset to the device
internal circuitry at power up. The RESET# input pin allows an external device to reset the FT232R.
RESET# can be tied to VCC or left unconnected if not being used.
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5 Devices Characteristics and Ratings
5.1 Absolute Maximum Ratings
The absolute maximum ratings for the FT232R devices are as follows. These are in accordance with the
Absolute Maximum Rating System (IEC 60134). Exceeding these may cause permanent damage to the
device.
Parameter
Value
Units
Storage Temperature
-65 to 150
°C
Floor Life (Out of Bag) At Factory Ambient
(30°C / 60% Relative Humidity)
168
(IPC/JEDEC J-STD-033A
MSL Level 3 Compliant)*
Hours
Ambient Temperature (Power Applied)
-40 to 85
°C
MTTF FT232RL
11162037
hours
MTTF FT232RQ
4464815
hours
VCC Supply Voltage
-0.5 to +6.00
V
DC Input Voltage – USBDP and USBDM
-0.5 to +3.8
V
DC Input Voltage – High Impedance
Bidirectional
-0.5 to + (VCC +0.5)
V
DC Input Voltage – All Other Inputs
-0.5 to + (VCC +0.5)
V
DC Output Current – Outputs
24
mA
DC Output Current – Low Impedance
Bidirectional
24
mA
Power Dissipation (VCC = 5.25V)
500
mW
Table 5.1 Absolute Maximum Ratings
* If devices are stored out of the packaging beyond this time limit the devices should be baked before
use. The devices should be ramped up to a temperature of +125°C and baked for up to 17 hours.
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5.2 DC Characteristics
DC Characteristics (Ambient Temperature = -40°C to +85°C)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
VCC1
VCC Operating Supply
Voltage
4.0
---
5.25
V
Using Internal
Oscillator
VCC1
VCC Operating Supply
Voltage
3.3
---
5.25
V
Using External
Crystal
VCC2
VCCIO Operating Supply
Voltage
1.8
---
5.25
V
Icc1
Operating Supply Current
---
15
---
mA
Normal Operation
Icc2
Operating Supply Current
50
70
100
μA
USB Suspend
3V3
3.3v regulator output
3.0
3.3
3.6
V
Table 5.2 Operating Voltage and Current
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
3.2
4.1
4.9
V
I source = 2mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 2mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.3 UART and CBUS I/O Pin Characteristics (VCCIO = +5.0V, Standard Drive Level)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.2
2.7
3.2
V
I source = 1mA
Vol
Output Voltage Low
0.3
0.4
0.5
V
I sink = 2mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.4 UART and CBUS I/O Pin Characteristics (VCCIO = +3.3V, Standard Drive Level)
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Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.1
2.6
2.8
V
I source = 1mA
Vol
Output Voltage Low
0.3
0.4
0.5
V
I sink = 2mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.5 UART and CBUS I/O Pin Characteristics (VCCIO = +2.8V, Standard Drive Level)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
1.32
1.62
1.8
V
I source = 0.2mA
Vol
Output Voltage Low
0.06
0.1
0.18
V
I sink = 0.5mA
Vin
Input Switching Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching Hysteresis
20
25
30
mV
**
Table 5.6 UART and CBUS I/O Pin Characteristics (VCCIO = +1.8V, Standard Drive Level)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
3.2
4.1
4.9
V
I source = 6mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 6mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.7 UART and CBUS I/O Pin Characteristics (VCCIO = +5.0V, High Drive Level)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.2
2.8
3.2
V
I source = 3mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 8mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.8 UART and CBUS I/O Pin Characteristics (VCCIO = +3.3V, High Drive Level)
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Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.1
2.6
2.8
V
I source = 3mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 8mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.9 UART and CBUS I/O Pin Characteristics (VCCIO = +2.8V, High Drive Level)
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
1.35
1.67
1.8
V
I source = 0.4mA
Vol
Output Voltage Low
0.12
0.18
0.35
V
I sink = 3mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
**
VHys
Input Switching
Hysteresis
20
25
30
mV
**
Table 5.10 UART and CBUS I/O Pin Characteristics (VCCIO = +1.8V, High Drive Level)
** Only input pins have an internal 200KΩ pull-up resistor to VCCIO
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Vin
Input Switching
Threshold
1.3
1.6
1.9
V
VHys
Input Switching
Hysteresis
50
55
60
mV
Table 5.11 RESET# and TEST Pin Characteristics
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
UVoh
I/O Pins Static
Output (High)
2.8
3.6
V
RI = 1.5kΩ to
3V3OUT (D+) RI =
15KΩ to GND (D-)
UVol
I/O Pins Static
Output (Low)
0
0.3
V
RI = 1.5kΩ to
3V3OUT (D+) RI =
15kΩ to GND (D-)
UVse
Single Ended Rx
Threshold
0.8
2.0
V
UCom
Differential
Common Mode
0.8
2.5
V
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FT232R USB UART IC Datasheet
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UVDif
Differential Input
Sensitivity
0.2
V
UDrvZ
Driver Output
Impedance
26
29
44
Ohms
See Note 1
Table 5.12 USB I/O Pin (USBDP, USBDM) Characteristics
5.3 EEPROM Reliability Characteristics
The internal 1024 Bit EEPROM has the following reliability characteristics:
Parameter
Value
Units
Data Retention
10
Years
Write
10,000
Cycles
Read
Unlimited
Cycles
Table 5.13 EEPROM Characteristics
5.4 Internal Clock Characteristics
The internal Clock Oscillator has the following characteristics:
Parameter
Value
Unit
Minimum
Typical
Maximum
Frequency of Operation
(see Note 1)
11.98
12.00
12.02
MHz
Clock Period
83.19
83.33
83.47
ns
Duty Cycle
45
50
55
%
Table 5.14 Internal Clock Characteristics
Note: Equivalent to +/-1667ppm
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.1
2.8
3.2
V
I source = 3mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 8mA
Vin
Input Switching
Threshold
1.0
1.2
1.5
V
Table 5.15 OSCI, OSCO Pin Characteristics – see Note 1
Note: When supplied, the FT232R is configured to use its internal clock oscillator. These characteristics
only apply when an external oscillator or crystal is used.
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5.5 Thermal Characteristics
The FT232RL package has the following thermal characteristics:
Parameter
Value
Units
Conditions
Theta JA (ƟJA)
55.82
°C/W
Still air
Theta JC (ƟJC)
24.04
°C/W
Table 5.16 FT232RL Thermal Characteristics
The FT232RQ package has the following thermal characteristics:
Parameter
Value
Units
Conditions
Theta JA (ƟJA)
31.49
°C/W
Still air, center pad soldered to PCB, 9 vias to another plane
Theta JA (ƟJA)
62.31
°C/W
Still air, center pad unsoldered
Theta JC (ƟJC)
°C/W
Table 5.17 FT232RQ Thermal Characteristics
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6 USB Power Configurations
The following sections illustrate possible USB power configurations for the FT232R. The illustrations have
omitted pin numbers for ease of understanding since the pins differ between the FT232RL and FT232RQ
package options.
All USB power configurations illustrated apply to both package options for the FT232R device. Please refer
to Section 3 for the package option pin-out and signal descriptions.
6.1 USB Bus Powered Configuration
Figure 6.1 Bus Powered Configuration
Figure 6.1 Illustrates the FT232R in a typical USB bus powered design configuration. A USB bus powered
device gets its power from the USB bus. Basic rules for USB bus power devices are as follows –
i) On plug-in to USB, the device should draw no more current than 100mA.
ii) In USB Suspend mode the device should draw no more than 2.5mA.
iii) A bus powered high power USB device (one that draws more than 100mA) should use one of
the CBUS pins configured as PWREN# and use it to keep the current below 100mA on plug-in
and 2.5mA on USB suspend.
iv) A device that consumes more than 100mA cannot be plugged into a USB bus powered hub.
v) No device can draw more than 500mA from the USB bus.
The power descriptors in the internal EEPROM of the FT232R should be programmed to match the current
drawn by the device.
A ferrite bead is connected in series with the USB power supply to reduce EMI noise from the FT232R and
associated circuitry being radiated down the USB cable to the USB host. The value of the Ferrite Bead
depends on the total current drawn by the application. A suitable range of Ferrite Beads is available from
Steward (www.steward.com), for example Steward Part # MI0805K400R-10.
Note: If using PWREN# (available using the CBUS) the pin should be pulled to VCCIO using a 10kΩ
resistor.
FT232R
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
100nF
3V3OUT
VCCIO
NC
RESET#
NC
+
100nF
10nF
Vcc
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS3
CBUS2
CBUS1
USBDP
USBDM
VCC
1
2
3
4
5
OSCI
OSCO
CBUS4
Ferrite
Bead
+
4.7uF
SHIELD
GND
GND
GND
GND
Vcc
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6.2 Self Powered Configuration
Figure 6.2 Self-Powered Configuration
Figure 6.2 illustrates the FT232R in a typical USB self-powered configuration. A USB self-powered device
gets its power from its own power supply, VCC, and does not draw current from the USB bus. The basic
rules for USB self-powered devices are as follows –
i) A self-powered device should not force current down the USB bus when the USB host or hub
controller is powered down.
ii) A self-powered device can use as much current as it needs during normal operation and USB
suspend as it has its own power supply.
iii) A self-powered device can be used with any USB host, a bus powered USB hub or a self-
powered USB hub.
The power descriptor in the internal EEPROM of the FT232R should be programmed to a value of zero
(self-powered).
In order to comply with the first requirement above, the USB bus power (pin 1) is used to control the
RESET# pin of the FT232R device. When the USB host or hub is powered up an internal 1.5kΩ resistor on
USBDP is pulled up to +3.3V (generated using the 4K7 and 10k resistor network), thus identifying the
device as a full speed device to the USB host or hub. When the USB host or hub is powered off, RESET#
will be low and the FT232R is held in reset. Since RESET# is low, the internal 1.5kΩ resistor is not pulled
up to any power supply (hub or host is powered down), so no current flows down USBDP via the 1.5kΩ
pull-up resistor. Failure to do this may cause some USB host or hub controllers to power up erratically.
Figure 6.2 illustrates a self-powered design which has a +4V to +5.25V supply.
Note:
1. When the FT232R is in reset, the UART interface I/O pins are tri-stated. Input pins have internal
200kΩ pull-up resistors to VCCIO, so they will gently pull high unless driven by some external
logic.
2. When using internal FT232R oscillator the VCC supply voltage range must be +4.0V to 5.25V.
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3. When using external oscillator the VCC supply voltage range must be +3.3V to 5.25V
Any design which interfaces to +3.3 V or +1.8V would be having a +3.3V or +1.8V supply to
VCCIO.
6.3 USB Bus Powered with Power Switching Configuration
FT232R
GND
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
2
3
4
GND
SHIELD
GND
100nF 4.7uF +
5
10nF+
Ferrite Bead
s d
g
P-Channel Power
MOSFET
PWREN#
1K
Switched 5V Power
To External Logic
Soft Start
Circuit
0.1uF 0.1uF
5V VCC
5V VCC
5V VCC
10K
Figure 6.3 Bus Powered with Power Switching Configuration
A requirement of USB bus powered applications, is when in USB suspend mode, the application draws a
total current of less than 2.5mA. This requirement includes external logic. Some external logic has the
ability to power itself down into a low current state by monitoring the PWREN# signal. For external logic
that cannot power itself down in this way, the FT232R provides a simple but effective method of turning
off power during the USB suspend mode.
Figure 6.3 shows an example of using a discrete P-Channel MOSFET to control the power to external
logic. A suitable device to do this is an International Rectifier (www.irf.com) IRLML6402, or equivalent. It
is recommended that a “soft start” circuit consisting of a 1kΩ series resistor and a 0.1μF capacitor is used
to limit the current surge when the MOSFET turns on. Without the soft start circuit it is possible that the
transient power surge, caused when the MOSFET switches on, will reset the FT232R or the USB host/hub
controller. The soft start circuit example shown in Figure 6.3 powers up with a slew rate of
approximaely12.5V/ms. Thus supply voltage to external logic transitions from GND to +5V in
approximately 400 microseconds.
As an alternative to the MOSFET, a dedicated power switch IC with inbuilt “soft-start” can be used. A
suitable power switch IC for such an application is the Micrel (www.micrel.com) MIC2025-2BM or
equivalent.
With power switching controlled designs the following should be noted:
i) The external logic to which the power is being switched should have its own reset circuitry to
automatically reset the logic when power is re-applied when moving out of suspend mode.
ii) Set the Pull-down on Suspend option in the internal FT232R EEPROM.
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iii) One of the CBUS Pins should be configured as PWREN# in the internal FT232R EEPROM, and used
to switch the power supply to the external circuitry. This should be pulled high through a 10 kΩ
resistor.
iv) For USB high-power bus powered applications (one that consumes greater than 100mA, and up
to 500mA of current from the USB bus), the power consumption of the application must be set in
the Max Power field in the internal FT232R EEPROM. A high-power bus powered application uses
the descriptor in the internal FT232R EEPROM to inform the system of its power requirements.
v) PWREN# gets its VCC from VCCIO. For designs using 3V3 logic, ensure VCCIO is not powered
down using the external logic. In this case use the +3V3OUT.
6.4 USB Bus Powered with Selectable External Logic Supply
FT232R
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
100nF 3V3OUT
VCCIO
NC
RESET#
NC
10nF
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS3
CBUS2
CBUS1
USBDP
USBDM
VCC
1
2
3
4
5
OSCI
OSCO
CBUS4
Ferrite
Bead
+
SHIELD
GND
GND
GND
3.3V or 5V
Supply to
External Logic
100nF
+
100nF
Vcc
4.7uF
GND
1
Jumper
SLEEP#
PWREN#
2
3
Vcc
VCCIO
10K
VCCIO
Figure 6.4 USB Bus Powered with +3.3V or +5V External Logic Power Supply
Figure 6.4 illustrates a USB bus power application with selectable external logic supply. The external logic
can be selected between +3.3V and +5V using the jumper switch. This jumper is used to allow the
FT232R to be interfaced with a +3.3V or +5V logic devices. The VCCIO pin is either supplied with +5V
from the USB bus (jumper pins1 and 2 connected), or from the +3.3V output from the FT232R 3V3OUT
pin (jumper pins 2 and 3 connected). The supply to VCCIO is also used to supply external logic.
With bus powered applications, the following should be noted:
i) To comply with the 2.5mA current supply limit during USB suspend mode, PWREN# or
SLEEP# signals should be used to power down external logic in this mode. If this is not
possible, use the configuration shown in Section 6.3.
ii) The maximum current sourced from the USB bus during normal operation should not exceed
100mA, otherwise a bus powered design with power switching (Section 6.3) should be used.
Another possible configuration could use a discrete low dropout (LDO) regulator which is supplied by the
5V on the USB bus to supply between +1.8V and +2.8V to the VCCIO pin and to the external logic. In
this case VCC would be supplied with the +5V from the USB bus and the VCCIO would be supplied from
the output of the LDO regulator. This results in the FT232R I/O pins driving out at between +1.8V and
+2.8V logic levels.
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For a USB bus powered application, it is important to consider the following when selecting the regulator:
i) The regulator must be capable of sustaining its output voltage with an input voltage of
+4.35V. A Low Drop Out (LDO) regulator should be selected.
ii) The quiescent current of the regulator must be low enough to meet the total current
requirement of <= 2.5mA during USB suspend mode.
A suitable series of LDO regulators that meets these requirements is the MicroChip/Telecom
(www.microchip.com) TC55 series of devices. These devices can supply up to 250mA current and have a
quiescent current of under 1μA.
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7 Application Examples
The following sections illustrate possible applications of the FT232R. The illustrations have omitted pin
numbers for ease of understanding since the pins differ between the FT232RL and FT232RQ package
options.
7.1 USB to RS232 Converter
FT232R
GND
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
2
3
4
GND
SHIELD
GND
100nF 4.7uF +
5
10nF +
Ferrite Bead
VCC
VCC
SLEEP#
GPIO2
GPIO3
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
RS232 LEVEL
CONVERTER
TXDATA
RXDATA
RTS
CTS
DTR
DSR
DCD
RI
TXLED#
RXLED#
VCC VCC
270R 270R
GND
RI
DTR
CTS
TXDATA
RTS
RXDATA
DSR
DCD
DB9M
SHIELD 10
5
9
4
8
3
7
2
6
1
SHDN#
Figure 7.1 Application Example showing USB to RS232 Converter
An example of using the FT232R as a USB to RS232 converter is illustrated in Figure 7.1. In this
application, a TTL to RS232 Level Converter IC is used on the serial UART interface of the FT232R to
convert the TTL levels of the FT232R to RS232 levels. This level shift can be done using the popular “213”
series of TTL to RS232 level converters. These “213” devices typically have 4 transmitters and 5 receivers
in a 28-LD SSOP package and feature an in-built voltage converter to convert the +5V (nominal) VCC to
the +/- 9 volts required by RS232. A useful feature of these devices is the SHDN# pin which can be used
to power down the device to a low quiescent current during USB suspend mode.
A suitable level shifting device is the Sipex SP213EHCA which is capable of RS232 communication at up
to 500k baud. If a lower baud rate is acceptable, then several pin compatible alternatives are available
such as the Sipex SP213ECA, the Maxim MAX213CAI and the Analogue Devices ADM213E, which are all
suitable for communication at up to 115.2k baud. If a higher baud rate is required, the Maxim
MAX3245CAI device is capable of RS232 communication rates up to 1Mbaud. Note that the MAX3245 is
not pin compatible with the 213 series devices and that the SHDN pin on the MAX device is active high
and should be connect to PWREN# pin instead of SLEEP# pin.
In example shown, the CBUS0 and CBUS1 have been configured as TXLED# and RXLED# and are being
used to drive two LEDs.
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7.2 USB to RS485 Converter
FT232R
GND
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
2
3
4
GND
SHIELD
GND
100nF 4.7uF +
5
10nF +
Ferrite Bead
Vcc
Vcc
TXD
RXD
GND DB9M
SHIELD 10
TXDEN
GPO
PWREN#
GPIO0
GPIO1
VCCIO
10K
RS485 LEVEL
CONVERTER
Vcc
SP481
5
1
2
3
4
Link
120R
7
6
Figure 7.2 Application Example Showing USB to RS485 Converter
An example of using the FT232R as a USB to RS485 converter is shown in Figure 7.2. In this application,
a TTL to RS485 level converter IC is used on the serial UART interface of the FT232R to convert the TTL
levels of the FT232R to RS485 levels.
This example uses the Sipex SP481 device. Equivalent devices are available from Maxim and Analogue
Devices. The SP481 is a RS485 device in a compact 8 pin SOP package. It has separate enables on both
the transmitter and receiver. With RS485, the transmitter is only enabled when a character is being
transmitted from the UART. The TXDEN signal CBUS pin option on the FT232R is provided for exactly this
purpose and so the transmitter enable is wired to CBUS2 which has been configured as TXDEN. Similarly,
CBUS3 has been configured as PWREN#. This signal is used to control the SP481’s receiver enable. The
receiver enable is active low, so it is wired to the PWREN# pin to disable the receiver when in USB
suspend mode. CBUS2 = TXDEN and CBUS3 = PWREN# are the default device configurations of the
FT232R pins.
RS485 is a multi-drop network; so many devices can communicate with each other over a two wire cable
interface. The RS485 cable requires to be terminated at each end of the cable. A link (which provides the
120Ω termination) allows the cable to be terminated if the SP481 is physically positioned at either end of
the cable.
In this example the data transmitted by the FT232R is also present on the receive path of the SP481.This
is a common feature of RS485 and requires the application software to remove the transmitted data from
the received data stream. With the FT232R it is possible to do this entirely in hardware by modifying the
example shown in Figure 7.2 by logically OR’ing the FT232R TXDEN and the SP481 receiver output and
connecting the output of the OR gate to the RXD of the FT232R.
Note that the TXDEN is activated 1 bit period before the start bit. TXDEN is deactivated at the same time
as the stop bit. This is not configurable.
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7.3 USB to RS422 Converter
FT232R
GND
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4-
1
2
3
4
GND
SHIELD
GND
100nF 4.7uF +
5
10nF +
Ferrite Bead
Vcc
Vcc
PWREN#
RS422 LEVEL
CONVERTER
Vcc
SP491
5
3
4
76
TXDM
TXDP
RXDP
RXDM
120R
10
9
11
12
SLEEP#
RS422 LEVEL
CONVERTER
SP491
3
4
76
Vcc
Vcc
10K
2
5
120R
11
12
9
10 RTSM
RTSP
CTSP
CTSM
GND DB9M
SHIELD
TXDM
TXDP
RXDP
RXDM
RTSM
RTSP
CTSP
CTSM
2
Figure 7.3 USB to RS422 Converter Configuration
An example of using the FT232R as a USB to RS422 converter is shown in Figure 7.3. In this application,
two TTL to RS422 Level Converter ICs are used on the serial UART interface of the FT232R to convert the
TTL levels of the FT232R to RS422 levels. There are many suitable level converter devices available. This
example uses Sipex SP491 devices which have enables on both the transmitter and receiver. Since the
SP491 transmitter enable is active high, it is connected to a CBUS pin in SLEEP# configuration. The
SP491 receiver enable is active low and is therefore connected to a CBUS pin PWREN# configuration. This
ensures that when both the SP491 transmitters and receivers are enabled then the device is active, and
when the device is in USB suspend mode, the SP491 transmitters and receivers are disabled. If a similar
application is used, but the design is USB BUS powered, it may be necessary to use a P-Channel logic
level MOSFET (controlled by PWREN#) in the VCC line of the SP491 devices to ensure that the USB
standby current of 2.5mA is met.
The SP491 is specified to transmit and receive data at a rate of up to 5 Mbaud. In this example the
maximum data rate is limited to 3 Mbaud by the FT232R.
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7.4 USB to MCU UART Interface
FT232R
GND
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
2
3
4
GND
SHIELD
GND
100nF 4.7uF +
5
10nF +
Ferrite Bead
Vcc
Vcc
PWREN#
Vcc
12MHz
OUT
10K
Microcontroller
CLK_IN
I/O
RTS#
RXD
TXD
CTS#
Vcc
Figure 7.4 USB to MCU UART Interface
An example of using the FT232R as a USB to Microcontroller (MCU) UART interface is shown in Figure
7.4. In this application the FT232R uses TXD and RXD for transmission and reception of data, and RTS# /
CTS# signals for hardware handshaking. Also in this example CBUS0 has been configured as a 12MHz
output to clock the MCU.
Optionally, RI# could be connected to another I/O pin on the MCU and used to wake up the USB host
controller from suspend mode. If the MCU is handling power management functions, then a CBUS pin can
be configured as PWREN# and would also be connected to an I/O pin of the MCU.
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7.5 LED Interface
Any of the CBUS I/O pins can be configured to drive an LED. The FT232R has 3 configuration options for
driving LEDs from the CBUS. These are TXLED#, RXLED#, and TX&RXLED#. Refer to Section 3.5 for
configuration options.
FT232R
CBUS[0...4]
CBUS[0...4]
VCCIO
TX
TXLED#
RXLED#
RX
270R 270R
Figure 7.5 Dual LED Configuration
An example of using the FT232R to drive LEDs is shown in Figure 7.5. In this application one of the CBUS
pins is used to indicate transmission of data (TXLED#) and another is used to indicate receiving data
(RXLED#). When data is being transmitted or received the respective pins will drive from tristate to low
in order to provide indication on the LEDs of data transfer. A digital one-shot is used so that even a small
percentage of data transfer is visible to the end user.
FT232R
CBUS[0...4] TX&RXLED#
270R
VCCIO
LED
Figure 7.6 Single LED Configuration
Another example of using the FT232R to drive LEDs is shown in Figure 7.6. In this example one of the
CBUS pins is used to indicate when data is being transmitted or received by the device (TX&RXLED). In
this configuration the FT232R will drive only a single LED.
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7.6 Using the External Oscillator
The FT232R defaults to operating using its own internal oscillator. This requires that the device is
powered with VCC(min)=+4.0V. This supply voltage can be taken from the USB VBUS. Applications which
require using an external oscillator, VCC= +3.3V, must do so in the following order:
1. When device powered for the very first time, it must have VCC > +4.0V. This supply is available
from the USB VBUS supply = +5.0V.
2. The EEPROM must then be programmed to enable external oscillator. This EEPROM modification
cannot be done using the FTDI programming utility, FT_PROG. The EEPROM can only be re-
configured from a custom application. Please refer to the following applications note on how to do
this:
AN_100_Using_The_FT232_245R_With_External_Osc
3. The FT232R can then be powered from VCC=+3.3V and an external oscillator. This can be done
using a link to switch the VCC supply.
The FT232R will fail to operate when the internal oscillator has been disabled, but no external oscillator
has been connected.
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8 Internal EEPROM Configuration
Following a power-on reset or a USB reset the FT232R will scan its internal EEPROM and read the USB
configuration descriptors stored there. The default factory programmed values of the internal EEPROM
are shown in Table 8.1.
Parameter
Value
Notes
USB Vendor ID (VID)
0403h
FTDI default VID (hex)
USB Product UD (PID)
6001h
FTDI default PID (hex)
Serial Number Enabled?
Yes
Serial Number
See Note
A unique serial number is generated and
programmed into the EEPROM during device final
test.
Pull down I/O Pins in USB
Suspend
Disabled
Enabling this option will make the device pull down
on the UART interface lines when in USB suspend
mode (PWREN# is high).
Manufacturer Name
FTDI
Product Description
FT232R USB UART
Max Bus Power Current
90mA
Power Source
Bus Powered
Device Type
FT232R
USB Version
0200
Returns USB 2.0 device description to the host.
Note: The device is a USB 2.0 Full Speed device
(12Mb/s) as opposed to a USB 2.0 High Speed
device (480Mb/s).
Remote Wake Up
Enabled
Taking RI# low will wake up the USB host controller
from suspend in approximately 20 ms.
High Current I/Os
Disabled
Enables the high drive level on the UART and CBUS
I/O pins.
Load VCP Driver
Enabled
Makes the device load the VCP driver interface for
the device.
CBUS0
TXLED#
Default configuration of CBUS0 – Transmit LED
drive.
CBUS1
RXLED#
Default configuration of CBUS1 – Receive LED drive.
CBUS2
TXDEN
Default configuration of CBUS2 – Transmit data
enable for RS485
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Parameter
Value
Notes
CBUS3
PWREN#
Default configuration of CBUS3 – Power enable. Low
after USB enumeration, high during USB suspend
mode.
CBUS4
SLEEP#
Default configuration of CBUS4 – Low during USB
suspend mode.
Invert TXD
Disabled
Signal on this pin becomes TXD# if enable.
Invert RXD
Disabled
Signal on this pin becomes RXD# if enable.
Invert RTS#
Disabled
Signal on this pin becomes RTS if enable.
Invert CTS#
Disabled
Signal on this pin becomes CTS if enable.
Invert DTR#
Disabled
Signal on this pin becomes DTR if enable.
Invert DSR#
Disabled
Signal on this pin becomes DSR if enable.
Invert DCD#
Disabled
Signal on this pin becomes DCD if enable.
Invert RI#
Disabled
Signal on this pin becomes RI if enable.
Table 8.1 Default Internal EEPROM Configuration
The internal EEPROM in the FT232R can be programmed over USB using the FTDI utility program
FT_PROG. FT_PROG can be downloaded from FTDI Utilities on the FTDI website (www.ftdichip.com).
Version 2.8a or later is required for the FT232R chip. Users who do not have their own USB Vendor ID
but who would like to use a unique Product ID in their design can apply to FTDI for a free block of unique
PIDs. Contact FTDI support for this service.
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9 Package Parameters
The FT232R is available in two different packages. The FT232RL is the SSOP-28 option and the FT232RQ
is the QFN-32 package option. The solder reflow profile for both packages is described in Section 9.5.
9.1 SSOP-28 Package Dimensions
Figure 9.1 SSOP-28 Package Dimensions
The FT232RL is supplied in a RoHS compliant 28 pin SSOP package. The package is lead (Pb) free and
uses a ‘green’ compound. The package is fully compliant with European Union directive 2002/95/EC.
This package is nominally 5.30mm x 10.20mm body (7.80mm x 10.20mm including pins). The pins are
on a 0.65 mm pitch. The above mechanical drawing shows the SSOP-28 package.
All dimensions are in millimetres.
The date code format is YYXX where XX = 2 digit week number, YY = 2 digit year number. This is
followed by the revision number.
The code XXXXXXXXXXXX is the manufacturing LOT code. This only applies to devices manufactured
after April 2009.
12° Typ
0° - 8°
0.25
0.75 +/-0.20
0.09
2.00 Max
1.75
+/- 0.10
0.05 Min
1.25 +/-0.12
FT232RL
YYXX-A
1
14 15
28
FTDI
5.30 +/-0.30
7.80 +/-0.40
10.20 +/-0.30
1.02 Typ.
0.30 +/-0.012
0.65 +/-0.026
XXXXXXXXXXXX
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9.2 QFN-32 Package Dimensions
Figure 9.2 QFN-32 Package Dimensions
The FT232RQ is supplied in a RoHS compliant leadless QFN-32 package. The package is lead ( Pb ) free,
and uses a ‘green’ compound. The package is fully compliant with European Union directive 2002/95/EC.
This package is nominally 5.00mm x 5.00mm. The solder pads are on a 0.50mm pitch. The above
mechanical drawing shows the QFN-32 package. All dimensions are in millimetres.
The centre pad on the base of the FT232RQ is not internally connected, and can be left unconnected, or
connected to ground (recommended).
The date code format is YYXX where XX = 2 digit week number, YY = 2 digit year number.
The code XXXXXXX is the manufacturing LOT code. This only applies to devices manufactured after April
2009.
Indicates Pin #1
(Laser Marked)
FT232RQ
32 25
24
17
169
8
1
YYXX-A
5.000 +/-0.075
5.000 +/-0.075
3.200 +/-0.100
3.200 +/-0.100
0.500
0.250 +/-0.050
0.500 +/-0.050
0.150 Max
Pin #1 ID
0.900 +/
-0.100
0.200 0.050
2
1
3
4
5
6
7
8
23
24
22
21
20
19
18
17
2526272829303132
161514131211109
Note: The pin #1 ID is connected internally to the device’s central
heat sink area . It is recommended to ground the central heat sink
area of the device.
0.200 Min
Dimensions in mm.
Central
Heat Sink
Area
FTDI
XXXXXXX
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9.3 QFN-32 Package Typical Pad Layout
Figure 9.3 Typical Pad Layout for QFN-32 Package
9.4 QFN-32 Package Typical Solder Paste Diagram
2.5 +/- 0.0375
2.5 +/- 0.0375
Figure 9.4 Typical Solder Paste Diagram for QFN-32 Package
1
17
25
0.500
0.30
0.200 Min
0.500
+/-0.050
0.150 Max
0.20
0.100
3.200 +/-0.100
3.200 +/-0.100
2.50
2.50
Optional GND
Connection
Optional GND
Connection
9
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9.5 Solder Reflow Profile
The FT232R is supplied in Pb free 28 LD SSOP and QFN-32 packages. The recommended solder reflow
profile for both package options is shown in Figure 9.5.
Figure 9.5 FT232R Solder Reflow Profile
The recommended values for the solder reflow profile are detailed in Table 9.1. Values are shown for both
a completely Pb free solder process (i.e. the FT232R is used with Pb free solder), and for a non-Pb free
solder process (i.e. the FT232R is used with non-Pb free solder).
Profile Feature
Pb Free Solder
Process
Non-Pb Free Solder Process
Average Ramp Up Rate (Ts to Tp)
3°C / second Max.
3°C / Second Max.
Preheat
- Temperature Min (Ts Min.)
- Temperature Max (Ts Max.)
- Time (ts Min to ts Max)
150°C
200°C
60 to 120 seconds
100°C
150°C
60 to 120 seconds
Time Maintained Above Critical
Temperature TL:
- Temperature (TL)
- Time (tL)
217°C
60 to 150 seconds
183°C
60 to 150 seconds
Peak Temperature (Tp)
260°C
240°C
Time within 5°C of actual Peak
Temperature (tp)
20 to 40 seconds
20 to 40 seconds
Critical Zone: when
T is in the range
T to T
Temperature, T (Degrees C)
Time, t (seconds)
25 P
T = 25º C to T
tp
Tp
TL
t
Preheat
S
tL
Ramp Up Lp
Ramp
Down
T Max
S
T Min
S
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Ramp Down Rate
6°C / second Max.
6°C / second Max.
Time for T= 25°C to Peak
Temperature, Tp
8 minutes Max.
6 minutes Max.
Table 9.1 Reflow Profile Parameter Values
Copyright © Future Technology Devices International Limited 41
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
10 Alternative Parts
The following lists of parts are not all direct drop in replacements but offer similar features as an
alternative to the FT232R. The FT-X series is the latest device family offering reduced power and pin
count with additional features such as battery charge detection, while the Hi-Speed solution offers faster
interfacing.
FT232R
FT234XD
FT230X
FT231X
FT232H
Description
Single
channel USB
to UART with
full modem
control lines
Single channel
USB to Basic
UART
Single channel
USB to Basic
UART
Single channel
USB to UART
with full modem
control lines
Single channel
USB to UART
with full modem
control lines
USB Speed
USB 2.0 full
speed
USB 2.0 full
speed
USB 2.0 full
speed
USB 2.0 full
speed
USB 2.0 hi-
speed
UART Data
Rates
3 MBaud
3 MBaud
3 MBaud
3 MBaud
12 MBaud
CBUS
5
1
4
4
10
MTP for storing
descriptors
Internal
Internal
Internal
Internal
External
Package
options
32 pin QFN
28 pin SSOP
12 pin DFN
(3mm x 3mm)
16 pin QFN
16 pin SSOP
20 pin QFN
20 pin SSOP
48 pin QFN
48 pin LQFP
Datasheet
FT232R
FT234XD
FT230X
FT231X
FT232H
Table 10.1 FT232R alternative solutions
Copyright © Future Technology Devices International Limited 42
FT232R USB UART IC Datasheet
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Document No.: FT_000053 Clearance No.: FTDI# 38
11 Contact Information
Head Office – Glasgow, UK
Future Technology Devices International Limited
Unit 1, 2 Seaward Place
Centurion Business Park
Glasgow, G41 1HH
United Kingdom
Tel: +44 (0) 141 429 2777
Fax: +44 (0) 141 429 2758
E-mail (Sales) sales1@ftdichip.com
E-mail (Support) support1@ftdichip.com
E-mail (General Enquiries) admin1@ftdichip.com
Web Shop URL http://www.ftdichip.com
Branch Office – Taipei, Taiwan
Future Technology Devices International Limited
(Taiwan)
2F, No 516, Sec. 1 NeiHu Road
Taipei 114
Taiwan, R.O.C.
Tel: +886 (0) 2 8797 1330
Fax: +886 (0) 2 8751 9737
E-mail (Sales) tw.sales1@ftdichip.com
E-mail (Support) tw.support1@ftdichip.com
E-mail (General Enquiries) tw.admin1@ftdichip.com
Branch Office – Tigard, Oregon, USA
Future Technology Devices International Limited (USA)
7130 SW Fir Loop
Tigard, OR 97223-8160
USA
Tel: +1 (503) 547 0988
Fax: +1 (503) 547 0987
E-Mail (Sales)
us.sales@ftdichip.com
E-Mail (Support)
us.support@ftdichip.com
E-Mail (General Enquiries)
us.admin@ftdichip.com
Branch Office – Shanghai, China
Future Technology Devices International Limited
(China)
Room 1103, No. 666 West Huaihai Road,
Shanghai, 200052
China
Tel: +86 21 62351596
Fax: +86 21 62351595
E-Mail (Sales) cn.sales@ftdichip.com
E-Mail (Support) cn.support@ftdichip.com
E-Mail (General Enquiries) cn.admin1@ftdichip.com
Web Site
http://www.ftdichip.com
Distributor and Sales Representatives
Please visit the Sales Network page of the FTDI Web site for the contact details of our distributor(s) and
sales representative(s) in your country.
System and equipment manufacturers and designers are responsible to ensure that their systems, and any Future Technology Devices
International Ltd (FTDI) devices incorporated in their systems, meet all applicable safety, regulatory and system-level performance
requirements. All application-related information in this document (including application descriptions, suggested FTDI devices and other
materials) is provided for reference only. While FTDI has taken care to assure it is accurate, this information is subject to customer
confirmation, and FTDI disclaims all liability for system designs and for any applications assistance provided by FTDI. Use of FTDI
devices in life support and/or safety applications is entirely at the user’s risk, and the user agrees to defend, indemnify and hold
harmless FTDI from any and all damages, claims, suits or expense resulting from such use. This document is subject to change without
notice. No freedom to use patents or other intellectual property rights is implied by the publication of this document. Neith er the whole
nor any part of the information contained in, or the product described in this document, may be adapted or reproduced in any material
or electronic form without the prior written consent of the copyright holder. Future Technology Devices International Ltd, Unit 1, 2
Seaward Place, Centurion Business Park, Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640
Copyright © Future Technology Devices International Limited 43
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Appendix A – References
Document References
AN_232R-01 Bit Bang Mode Available for FT232R and FT245R
AN_107-Advanced Driver Options
AN232R-02 FTDIChip-ID for the FT232R and FT245R
AN_121- Accessing the EEPROM User Area of FTDI Devices
AN_120 Aliasing VCP Baud Rates
AN_100 – Using the FT232R/FT245R with an External Crystal or Oscillator
AN_126 – User Guide for FT232B/R Factory Test Utility
AN232B-05 Configuring FT232R, FT2232 and FT232B Baud Rates
http://www.ftdichip.com/Documents/InstallGuides.htm
FT_PROG
Acronyms and Abbreviations
Terms
Description
EEPROM
Electrically Erasable Programmable Read-Only Memory
FPGA
Field Programmable Gate Array
LED
Light Emitting Diode
MCU
Micro Controller Unit
PLD
Programmable Logic Device
QFN
Quad Flat No-leads
RoHS
Restriction of Hazardous Substances Directive
SIE
Serial Interface Engine
UART
Universal Asynchronous Receiver/Transmitter
USB
Universal Serial Bus
VCP
Virtual Communication Port
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FT232R USB UART IC Datasheet
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Appendix B – List of Figures and Tables
List of Figures
Figure 2.1 FT232R Block Diagram ................................................................................................... 4
Figure 3.1 SSOP Package Pin Out and Schematic Symbol ................................................................... 7
Figure 3.2 QFN-32 Package Pin Out and schematic symbol .............................................................. 10
Figure 6.1 Bus Powered Configuration ........................................................................................... 23
Figure 6.2 Self Powered Configuration ........................................................................................... 24
Figure 6.3 Bus Powered with Power Switching Configuration ............................................................ 25
Figure 6.4 USB Bus Powered with +3.3V or +5V External Logic Power Supply .................................... 26
Figure 7.1 Application Example showing USB to RS232 Converter ..................................................... 28
Figure 7.2 Application Example Showing USB to RS485 Converter .................................................... 29
Figure 7.3 USB to RS422 Converter Configuration ........................................................................... 30
Figure 7.4 USB to MCU UART Interface .......................................................................................... 31
Figure 7.5 Dual LED Configuration ................................................................................................ 32
Figure 7.6 Single LED Configuration .............................................................................................. 32
Figure 9.1 SSOP-28 Package Dimensions ....................................................................................... 36
Figure 9.2 QFN-32 Package Dimensions ......................................................................................... 37
Figure 9.3 Typical Pad Layout for QFN-32 Package .......................................................................... 38
Figure 9.4 Typical Solder Paste Diagram for QFN-32 Package ........................................................... 38
Figure 9.5 FT232R Solder Reflow Profile ........................................................................................ 39
List of Tables
Table 3.1 USB Interface Group ....................................................................................................... 7
Table 3.2 Power and Ground Group ................................................................................................. 8
Table 3.3 Miscellaneous Signal Group .............................................................................................. 8
Table 3.4 UART Interface and CUSB Group (see note 3) .................................................................... 9
Table 3.5 USB Interface Group ..................................................................................................... 10
Table 3.6 Power and Ground Group ............................................................................................... 11
Table 3.7 Miscellaneous Signal Group ............................................................................................ 11
Table 3.8 UART Interface and CBUS Group (see note 3) .................................................................. 12
Table 3.9 CBUS Configuration Control ........................................................................................... 13
Table 5.1 Absolute Maximum Ratings ............................................................................................ 17
Table 5.2 Operating Voltage and Current ....................................................................................... 18
Table 5.3 UART and CBUS I/O Pin Characteristics (VCCIO = +5.0V, Standard Drive Level) .................. 18
Table 5.4 UART and CBUS I/O Pin Characteristics (VCCIO = +3.3V, Standard Drive Level) .................. 18
Table 5.5 UART and CBUS I/O Pin Characteristics (VCCIO = +2.8V, Standard Drive Level) .................. 19
Table 5.6 UART and CBUS I/O Pin Characteristics (VCCIO = +1.8V, Standard Drive Level) .................. 19
Copyright © Future Technology Devices International Limited 45
FT232R USB UART IC Datasheet
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Table 5.7 UART and CBUS I/O Pin Characteristics (VCCIO = +5.0V, High Drive Level) ......................... 19
Table 5.8 UART and CBUS I/O Pin Characteristics (VCCIO = +3.3V, High Drive Level) ......................... 19
Table 5.9 UART and CBUS I/O Pin Characteristics (VCCIO = +2.8V, High Drive Level) ......................... 20
Table 5.10 UART and CBUS I/O Pin Characteristics (VCCIO = +1.8V, High Drive Level) ....................... 20
Table 5.11 RESET# and TEST Pin Characteristics ............................................................................ 20
Table 5.12 USB I/O Pin (USBDP, USBDM) Characteristics ................................................................. 21
Table 5.13 EEPROM Characteristics ............................................................................................... 21
Table 5.14 Internal Clock Characteristics ....................................................................................... 21
Table 5.15 OSCI, OSCO Pin Characteristics – see Note 1 ................................................................. 21
Table 5.16 FT232RL Thermal Characteristics .................................................................................. 22
Table 5.17 FT232RQ Thermal Characteristics .................................................................................. 22
Table 8.1 Default Internal EEPROM Configuration ............................................................................ 35
Table 9.1 Reflow Profile Parameter Values ..................................................................................... 40
Table 10.1 FT232R alternative solutions ........................................................................................ 41
Copyright © Future Technology Devices International Limited 46
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Appendix C – Revision History
Document Title: FT232R USB UART IC Datasheet
Document Reference No.: FT_000053
Clearance No.: FTDI# 38
Product Page: http://www.ftdichip.com/FTProducts.htm
Document Feedback: Send Feedback
Revision
Changes
Date
Version 0.90
Initial Release
August 2005
Version 0.96
Revised Pre-release datasheet
October 2005
Version 1.00
Full Datasheet Release
December 2005
Version 1.02
Minor revisions to datasheet
December 2005
Version 1.03
Manufacturer ID added to default EEPROM
configuration; Buffer sizes added
January 2006
Version 1.04
QFN-32 Pad layout and solder paste diagrams added
January 2006
Version 2.00
Reformatted, updated package info, added notes for
3.3V operation;
Part numbers, TID; added UART and CBUS
characteristics for +1.8V;
Corrected RESET#; Added MTTF data;
Corrected the input switching threshold and input
hysteresis values for VCCIO=5V
June 2008
Version 2.01
Corrected pin-out number in table3.2 for GND pin18.
Improved graphics on some Figures.
Add packing details. Changed USB suspend current
spec from 500uA to 2.5mA
Corrected Figure 9.2 QFN dimensions.
August 2008
Version 2.02
Corrected Tape and Reel quantities.
Added comment “PWREN# should be used with a
10kΩ resistor pull up”.
Replaced TXDEN# with TXDEN since it is active high
in various places.
Added lot number to the device markings.
Added 3V3 regulator output tolerance.
Clarified VCC operation and added section headed
“Using an external Oscillator”
Updated company contact information.
April 2009
Copyright © Future Technology Devices International Limited 47
FT232R USB UART IC Datasheet
Version 2.14
Document No.: FT_000053 Clearance No.: FTDI# 38
Revision
Changes
Date
Version 2.03
Corrected the RX/TX buffer definitions to be relative
to the USB interface
June 2009
Version 2.04
Additional dimensions added to QFN solder profile
June 2009
Version 2.05
Modified package dimensions to 5.0 x 5.0 +/-
0.075mm and Solder paste diagram to 2.50 x 2.50
+/-0.0375mm
Added Windows 7 32, 64 bit driver support
Added FT_PROG utility references
Added Appendix A-references. Figure 2.1 updated.
Updated USB-IF TID for Rev B
December 2009
Version 2.06
Updated section 6.2, Figure 6.2 and the note,
Updated section 5.3, Table 5.13, EEPROM data
retention time
May 2010
Version 2.07
Added USB Certification Logos
July 2010
Version 2.08
Updated USB-IF TID for Rev C
April 2011
Version 2.09
Corrected Rev C TID number
April 2011
Version 2.10
Table 3.9, added clock output frequency within
±0.7%
Edited Table 3.9, TXLED# and TXLED# Description
Added feedback links
March 2012
Version 2.11
Added thermal characteristics (Section 5.5)
Added section 10 highlighting alternative solutions
from FTDI
April 2015
Version 2.12
Updated the links under section A – References –
Useful Application Notes
Updated list of OS with supported drivers
August 2015
Version 2.13
Update Typo error in section heading 7.2 USB to
RS485 Converter
2015-11-18
Version 2.14
Changes made to Bitbang WRn CBUS signal
availability in Table 3.9.
2018-06-27