1
10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
■ Operates From A Single +3.3V Supply
■ Interoperable With +5V Logic
■ +200mV Receiver Input Sensitivity
■ -7V to +12V Common-Mode Input
Voltage Range
■ Devices Allow Up To 32 Transceivers
On The Serial Bus
■ Driver/Receiver Enable Lines (SP3494)
■ 2nA Low-Power Shutdown Mode (SP3494)
■ Compatible With The MAX3488, LTC490
and 75179 Industry Standard Pinouts
(SP3493)
■ Compatible With The MAX3486 and 75176
Industry Standard Pinouts (SP3494)
+3.3V Low Power
RS-485/RS-422 Transceivers
SP3493/SP3494
DESCRIPTION
The SP3493 and the 3494 devices are +3.3V, low power transceivers that meet the
specifications of the RS-485 and RS-422 serial protocols. The SP3493 and the 3494 devices
are pin-to-pin compatible with the Sipex SP3490 and the SP3481 devices, respectively, as well
as other popular industry standards. The devices feature Sipex's BiCMOS process, allowing
low power operation without sacrificing performance. The partially slew-rate limited drivers
minimize EMI and reduce reflections caused by improperly terminated cables allowing
error-free data transmission. The SP3493 is a full-duplex low power transceiver that will
deliver a data transmission rate up to 250kbps. The SP3494 is a half-duplex partially slew-rate
limited transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is
equipped with a low-power shutdown mode and driver/receiver high-Z enable lines.
1
2
3
45
6
7
8
R
D
Vcc
GND
R
D
A
B
Z
Y
RO 1
RE 2
DE 3
DI 4
8 VCC
7 B
6 A
5 GND
D
R
SP3493 SP3494
®
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
SPECIFICATIONS
TAMB = TMIN to TMAX and VCC = 3.3V ± 5% unless otherwise noted.
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP3493 DRIVER
DC Characteristics
Differential Output Voltage GND VCC Volts Unloaded; R = ∞ Ω;
Figure 1
Differential Output Voltage 2 VCC Volts With Load; R = 50Ω; (RS-422);
Figure 1
Differential Output Voltage 1.5 VCC Volts W
ith Load; R = 27
Ω
; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States 0.2 Volts R = 27Ω or R = 50Ω;
Figure 1
Driver Common-Mode
Output Voltage 3 Volts R = 27Ω or R = 50Ω;
Figure 1
Input High Voltage 2.0 Volts
Input Low Voltage 0.8 Volts
Input Current +10 µA
Driver Short-Circuit Current
VOUT = HIGH +250 mA -7V < VO < +12V
VOUT = LOW +250 mA -7V < VO < +12V
SP3493 DRIVER
AC Characteristics
Maximum Data Rate 250 kbps
Driver Input to Output, tPLH 400 900 1500 ns
Figures 2 and 8
Driver Input to Output, tPHL 400 900 1500 ns
Figures 2 and 8
Differential Driver Skew 10 ns t PHL(Y) - tPLH(Y) , tPHL(Z) - tPLH(Z) ,
Figures 2 and 8
Figures 2 and 8
Driver Rise or Fall Time 10 30 ns From 10% to 90%;
Figures 3 and 9
SP3493
RECEIVER
DC Characteristics
Differential Input Threshold 0.2 +0.2 Volts -7V < VCM < 12V
Input Hysteresis 25 mV VCM = 0V
Output Voltage High VCC-0.4 Volts IO = -1.5mA, VID = +200mV
Output Voltage Low 0.4 Volts IO = +2.5mA, VID = -200mV
Input Resistance 12 15 kΩ-7V < VCM < 12V
Input Current (A, B); VIN = 12V 1.0 mA VIN = 12V
Input Current (A, B); VIN = -7V -0.8 mA VIN = -7V
Short-Circuit Current 60 mA 0V < VO < VCC
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of the device at
these ratings or any other above those indicated in the operation sections
of the specifications below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect reliability.
VCC ............................................................................................ +6.0V
Input Voltages
Drivers ........................................................................ -0.3V to +6.0V
Receivers................................................................................... ±14V
Output Voltages
Drivers ....................................................................................... ±14V
Receivers.................................................................... -0.3V to +6.0V
Storage Temperature ................................................. -65˚C to +150˚
Power Dissipation per Package
8-pin PDIP (derate11.8mW/oC above +70oC) ...................... 1000mW
8-pin NSOIC (derate 6.90mW/oC above +70oC) .................... 600mW
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
SPECIFICATIONS (continued)
TAMB = TMIN to TMAX and VCC = 3.3V ± 5% unless otherwise noted.
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP3493 RECEIVER
AC Characteristics
Maximum Data Rate 250 kbps
Receiver Input to Output, tPLH 35 70 120 ns
Figures 6 and 11
Receiver Input to Output, tPHL 35 70 120 ns
Figures 6 and 11
Differential Receiver Skew 10 ns
Figures 6 and 11
SP3493 POWER REQUIREMENTS
Supply Current 1000 2000 µAD = 0 or VCC
SP3494 DRIVER
DC Characteristics
Differential Output Voltage GND VCC Volts Unloaded; R = ∞;
Figure 1
Differential Output Voltage 2 VCC Volts with load; R = 50Ω; (RS-422);
Figure 1
Differential Output Voltage 1.5 VCC Volts with load; R = 27Ω; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States 0.2 Volts R = 27Ω or R = 50Ω;
Figure 1
Driver Common-Mode
Output Voltage 3 Volts R = 27Ω or R = 50Ω;
Figure 1
Input High Voltage 2.0 Volts Applies to DE, DI, RE
Input Low Voltage 0.8 Volts Applies to DE, DI, RE
Input Current +10 µAApplies to DE, DI, RE
Driver Short-Circuit Current
VOUT = HIGH +250 mA -7V < VO < +12V
VOUT = LOW +250 mA -7V < VO < +12V
SP3494 DRIVER
AC Characteristics
Maximum Data Rate 2.5 Mbps RE = VCC, DE = VCC
Driver Input to Output, tPLH 20 45 75 ns
Figures 2 and 8
Driver Input to Output, tPHL 20 45 75 ns
Figures 2 and 8
Differential Driver Skew 10 ns tDO1 - tDO2 ,
Figures 2 and 9
Driver Rise or Fall Time 30 70 ns From 10% to 90%,
Figures 3 and
9
Driver Enable to Output High 52 120 ns
Figures 4 and 10
Driver Enable to Output Low 60 120 ns
Figures 5 and 10
Driver Disable Time from Low 40 120 ns
Figures 5 and 10
Driver Disable Time from High 60 120 ns
Figures 4 and 10
SP3494
RECEIVER
DC Characteristics
Differential Input Threshold -0.2 +0.2 Volts -7V < VCM < +12V
Input Hysteresis 20 mV VCM = 0V
Output Voltage High V CC-0.4 Volts VID = +200mV, -1.5mA
Output Voltage Low 0.4 Volts VID = -200mV, 2.5mA
Three-State (High Impedance)
Output Current +1 µA 0V < VO < VCC; RE = VCC
Input Resistance 12 15 kΩ-7V < VCM < +12V
Input Current (A, B); VIN = 12V 1.0 mA DE = 0V, VCC = 0V or 3.6V, VIN = 12V
Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 3.6V, VIN = -7V
Short-Circuit Current 7 60 mA 0V < VCM < VCC
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
SPECIFICATIONS (continued)
TAMB = TMIN to TMAX and VCC = +3.3V ± 5% unless otherwise noted.
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP3494 RECEIVER
AC Characteristics
Maximum Data Rate 2.5 Mbps RE = 0V, DE = 0V
Receiver Input to Output, tPLH 40 70 100 ns
Figures 6 and 11
Receiver Input to Output, tPHL 40 70 100 ns
Figures 6 and 11
Differential Receiver Skew 10 ns tRSKEW = tRPHL - tRPLH ,
Figures 6 and 11
Receiver Enable to
Output Low 35 60 ns
Figures 7 and 12
; S1 closed, S2 open
Receiver Enable to
Output High 35 60 ns
Figures 7 and 12
; S2 closed, S1 open
Receiver Disable from Low 35 60 ns
Figures 7 and 12
; S1 closed, S2 open
Receiver Disable from High 35 60 ns
Figures 7 and 12
; S2 closed, S1 open
SP3494 SHUTDOWN TIMING
Time to Shutdown 50 75 200 ns RE = 3.3V, DE = 0V
Driver Enable from Shutdown
to Output High 65 150 ns
Figures 4 and 10
Driver Enable from Shutdown
to Output Low 65 150 ns
Figures 5 and 10
Receiver Enable from
Shutdown to Output High 50 200 ns
Figures 7 and 12;
S2 closed, S1 open
Receiver Enable from
Shutdown to Output Low 50 200 ns
Figures 7 and 12;
S1 closed, S2 open
SP3494 POWER REQUIREMENTS
Supply Current
No Load 1000 2000 µARE, DI = 0V or VCC; DE = VCC
800 1500 µARE = 0V, DI = 0V or VCC; DE = 0V
Shutdown Mode 10 µADE = 0V, RE=VCC
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
PIN FUNCTION - SP3493
Pin 1 - VCC - Positive supply +3.00 < VCC < +3.60
Pin 2 - R - Receiver output.
Pin 3 - D - Driver input.
Pin 4 - GND - Ground connection.
Pin 5 - Y - Non-inverting driver output.
Pin 6 - Z - Inverting driver output.
Pin 7 - B - Inverting receiver input.
Pin 8 - A - Non-inverting receiver input.
1
2
3
45
6
7
8
R
D
Vcc
GND
R
D
A
B
Z
Y
PIN FUNCTION - SP3494
Pin 1 – RO – Receiver Output.
Pin 2 – RE – Receiver Output Enable Active LOW.
Pin 3 – DE – Driver Output Enable Active HIGH.
Pin 4 – DI – Driver Input.
Pin 5 – GND – Ground Connection.
Pin 6 – A – Driver Output/Receiver Input
Non-inverting.
Pin 7 – B – Driver Output/Receiver Input Inverting.
Pin 8 – Vcc – Positive Supply +3.00V < V
CC
< +3.60V
SP3494
Pinout
RO 1
RE 2
DE 3
DI 4
8 VCC
7 B
6 A
5 GND
D
R
SP3493
Pinout
6
10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
DESCRIPTION
The SP3493/3494 are +3.3V transceivers that
meet the electrical specifications of the
RS-485 and RS-422 serial protocols. The
SP3493/3494 feature Sipex's BiCMOS process
allowing low power operation without
sacrificing performance.
The SP3493 device is a +3.3V full-duplex
transceiver that is pin-to-pin compatible with
the Sipex SP3490 and SP490 devices as well as
popular industry standards such as the
MAX3488, the LTC490, and the 75179. The
SP3493 has a driver with a data transmission
rate of 250kbps.
The SP3494 device is a +3.3V half-duplex
transceiver that is pin-to-pin compatible with
the Sipex SP3481 and SP481 devices as well as
popular industry standards such as the MAX3486
and the 75176. The SP3494 has a partially slew-
rate limited driver with a data transmission rate
of 2.5Mbps.
Drivers
The SP3493/3494devices both have differential
outputs. The typical voltage output swing with
no load will bo 0V to VCC. With worst case
loading of 54Ω across the differential outputs,
the driver can maintain greater than 1.5V voltage
levels.
The SP3494 device has an enable control line
which is active HIGH. A logic HIGH on DE (pin
3) will enable the differential driver outputs.
A logic LOW on DE (pin 3) will force the driver
outputs at high impedance (high-Z). The SP3493
device does not have a driver enable.
The SP3493/SP3494 drivers will operate up to
250kbps and 2.5Mbps, respectively. In addition
to adhering to the 250mA ISC maximum limit on
the driver output, the driver output short-circuit
protection will allow the devices to withstand an
infinite short circuit over the -7.0V to +12V
common mode range without damage.
Receivers
The receivers have differential inputs with an
input sensitivity as low +200mV. Input
impedance of the receivers is typically 15kΩ
(12kΩ minimum). A wide common mode range
of -7V to +12V allows for large ground potential
differences between systems.
Both the SP3493/SP3494 receivers are
equipped with fail-safe which guarantees that
the receiver outputs will be in a high state
when the input is left unconnected.
The SP3494 receiver has a high impedance
(high-Z) enable control pin. A logic LOW on
RE (pin 2) will enable the receiver; a logic
HIGH on RE (pin 2) will disable the receiver.
The SP3494 is equipped with a shutdown mode.
To enable the shutdown state, both the driver
and receiver must be disabled simultaneously.
A logic LOW on DE (pin 3) and a logic HIGH
on RE (pin 2) will put the SP3494 into shutdown.
In shutdown, the supply current will drop to 2nA
typical, 1µA maximum.
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
INPUTS OUTPUTS
LINE
RE DE DI CONDITION B A
X11No Fault 0 1
X10No Fault 1 0
X0X X ZZ
INPUTS OUTPUTS
RE DE A - B R
00 +0.2V 1
00 -0.2V 0
00Inputs Open 1
10 X Z
Table 1. Transmit Function Truth Table Table 2. Receive Function Truth Table
Figure 1. Driver DC Test Load Circuit
Figure 7. Receiver Enable and Disable Timing Circuit
R
RVOC
D
VCC
VOD
GENERATOR
(NOTE 1) 50Ω
V
CC
S1
V
DM
R
L
= 27Ω
OUT
C
L
= 15pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1) 50Ω
S1
R
L
= 110Ω
OUT
C
L
= 50pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1) 50Ω
S1 R
L
= 110Ω
OUT
C
L
= 50pF
(NOTE 2)
D
0V OR 3V
V
CC
GENERATOR
(NOTE 1) 50Ω
1.5V
0V
V
ID
ROUT
CL = 15pF
(NOTE 2)
V
OM
= V
CC
2
1.5V
-1.5V
S3
VID
GENERATOR
(NOTE 1) 50Ω
CL = 15pF
(NOTE 2)
R
1k
S1
S2
VCC
Figure 5. Driver Enable and Disable Timing Circuit,
Output LOW
GENERATOR
(NOTE 1) 50Ω
C
L
OUT
D
V
CC
R
L
=
60Ω
C
L
= 15pF (NOTE 2)
Figure 3. Driver Differential Output Delay and
Transition Time Circuit
Figure 2. Driver Propagation Delay Test Circuit
Figure 6. Receiver Propagation Delay Test Circuit
Figure 4. Driver Enable and Disable Timing Circuit,
output HiGH
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
Figure 8. Driver Propagation Delay Waveforms
Figure 12. Receiver Enable and Disable Waveforms
Figure 11. Receiver Propagation Delay Waveforms
Figure 10. Driver Enable and Disable Timing Waveforms
0V
VOH tPLH tPHL
V
OM
tPHL tPLH
3V
VOL
VOH
1.5V 1.5V
INPUT
Y OUTPUT
V
OM
Z OUTPUT
VOL
V
OM
V
OM
V
OM
= V
OH
+ V
OL
2≈ 1.5V
0V
VOH tPZH
0.25V
tPHZ
V
OM
tPZL tPLZ
3V
VOL
VCC
1.5V 1.5V
DE
OUTPUT
HIGH
V
OM
0.25V
0V
OUTPUT
LOW
V
OM
= V
OH
+ V
OL
2≈ 1.5V
3V
0V
VCC tRPLH
1.5V
tRPHL
VOM VOM
0V
1.5V
INPUT
OUTPUT
VOM = VCC
2
3V
0V tPRHZ
1.5V
tPRZH
tPRSH
1.5V
1.5V
10%
0V
VOH
RE
OUTPUT
S1 is open
S2 is closed
S3 = 1.5V 3V
0V t
PRLZ
1.5V
tPRZL
tPRSL
1.5V
1.5V
10%
VCC
RE
OUTPUT
S1 is closed
S2 is open
S3 = -1.5V
VOL
NOTE 1: The input pulse is supplied by a generator with the following characteristics:
PRR=250KHz, 50% duty cycle, tr < 6.0ns, Z0=50Ω.
NOTE 2: CL includes probe and stray capacitance.
IN 1.5V
t
DO1
1.5V
t
DO2
3V
0V
OUT 50% 50%
10% 10%
90% 90%
t
TD
t
TD
2.0V
-2.0V
Figure 9. Driver Differential Output Delay and
Transition Time Waveforms
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10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
D
ALTERNATE
END PINS
(BOTH ENDS)
D1 = 0.005" min.
(0.127 min.)
E
PACKAGE: PLASTIC
DUAL–IN–LINE
(NARROW)
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
A = 0.210" max.
(5.334 max).
E1
C
Ø
LA2
A1 = 0.015" min.
(0.381min.)
B
B1
e = 0.100 BSC
(2.540 BSC) eA = 0.300 BSC
(7.620 BSC)
A2
B
B1
C
D
E
E1
L
Ø
0.115/0.195
(2.921/4.953)
0.014/0.022
(0.356/0.559)
0.045/0.070
(1.143/1.778)
0.008/0.014
(0.203/0.356)
0.355/0.400
(9.017/10.160)
0.300/0.325
(7.620/8.255)
0.240/0.280
(6.096/7.112)
0.115/0.150
(2.921/3.810)
0°/ 15°
(0°/15°)
8–PIN
10
10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
D
EH
PACKAGE: PLASTIC
SMALL OUTLINE (SOIC)
(NARROW)
DIMENSIONS (Inches)
Minimum/Maximum
(mm) 8–PIN
A
A1
Ø
L
Be
h x 45°
A
A1
B
D
E
e
H
h
L
Ø
0.053/0.069
(1.346/1.748)
0.004/0.010
(0.102/0.249
0.014/0.019
(0.35/0.49)
0.189/0.197
(4.80/5.00)
0.150/0.157
(3.802/3.988)
0.050 BSC
(1.270 BSC)
0.228/0.244
(5.801/6.198)
0.010/0.020
(0.254/0.498)
0.016/0.050
(0.406/1.270)
0°/8°
(0°/8°)
11
10/16/02 SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers © Copyright 2002 Sipex Corporation
ORDERING INFORMATION
Model Temperature Range Package
SP3493CN 0˚C to +70˚C 8-pin Narrow SOIC
SP3493CP 0˚C to +70˚C 8-pin Plastic DIP
SP3493EN .-40˚C to +85˚C 8-pin Narrow SOIC
SP3493EP -40˚C to +85˚C 8-pin Plastic DIP
SP3494CN 0˚C to +70˚C 8-pin Narrow SOIC
SP3494CP 0˚C to +70˚C 8-pin Plastic DIP
SP3494EN -40˚C to +85˚C 8-pin Narrow SOIC
SP3494EP -40˚C to +85˚C 8-pin Plastic DIP
Please consult the factory for pricing and availability on a Tape-On-Reel option.
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Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
