1. General description
The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlled
by the I2C-bus. The low ON-state resistance of the switch allows connections to be made
with minimal propagation delay. Any individual A to B channel or combination of channels
can be selected via the I2C-bus, determined by the contents of the programmable Control
register. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow from
Port A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open,
creating a high-impedance state between the two ports, which stops the data flow.
An active LOW reset input (RESET) allows the PCA9549 to recover from a situation
where the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-bus
state machine and causes all the bits to be open, as does the internal power-on reset
function.
Three address pins allow up to eight devices on the same bus.
2. Features
n8-bit bus switch (CBT)
n5 switch connection between two ports
nI2C-bus interface logic; compatible with SMBus standards
nActive LOW RESET input
n3 address pins allowing up to 8 devices on the I2C-bus
nBit selection via I2C-bus, in any combination
nPower-up with all bits deselected
nLow Ron switches
nNo glitch on power-up
nSupports hot insertion
nLow standby current
nOperating power supply voltage range of 2.3 V to 5.5 V
n5 V tolerant inputs
n0 Hz to 400 kHz clock frequency
nESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per
JESD22-A115 and 1000 V CDM per JESD22-C101
nLatch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
nPackages offered: SO24, TSSOP24, HVQFN24
PCA9549
Octal bus switch with individually I2C-bus controlled enables
Rev. 02 — 13 July 2009 Product data sheet
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 2 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
3. Ordering information
3.1 Ordering options
4. Block diagram
Table 1. Ordering information
Type number Package
Name Description Version
PCA9549D SO24 plastic small outline package; 24 leads;
body width 7.5 mm SOT137-1
PCA9549PW TSSOP24 plastic thin shrink small outline package; 24 leads;
body width 4.4 mm SOT355-1
PCA9549BS HVQFN24 plastic thermal enhanced very thin quad flat package;
no leads; 24 terminals; body 4 ×4×0.85 mm SOT616-1
Table 2. Ordering options
Type number Topside mark Temperature range
PCA9549D PCA9549D 40 °C to +85 °C
PCA9549PW PCA9549 40 °C to +85 °C
PCA9549BS 9549 40 °C to +85 °C
Fig 1. Block diagram
SWITCH CONTROL LOGIC
PCA9549
RESET
CIRCUIT
002aaa991
1A
2A
3A
4A
5A
6A
7A
8A
VSS
VDD
RESET
I2C-BUS
CONTROL
INPUT
FILTER
SCL
SDA
A0
A1
A2
1B
2B
3B
4B
5B
6B
7B
8B
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 3 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
5. Pinning information
5.1 Pinning
Fig 2. Pin configuration of SO24 Fig 3. Pin configuration of TSSOP24
Fig 4. Pin configuration of HVQFN24 (transparent top view)
PCA9549D
A0 VDD
A1 SDA
RESET SCL
1A A2
1B 8A
2A 8B
2B 7A
3A 7B
3B 6A
4A 6B
4B 5A
VSS 5B
002aaa992
1
2
3
4
5
6
7
8
9
10
11
12
14
13
16
15
18
17
20
19
22
21
24
23
PCA9549PW
A0 VDD
A1 SDA
RESET SCL
1A A2
1B 8A
2A 8B
2B 7A
3A 7B
3B 6A
4A 6B
4B 5A
VSS 5B
002aaa993
1
2
3
4
5
6
7
8
9
10
11
12
14
13
16
15
18
17
20
19
22
21
24
23
002aaa994
PCA9549BS
Transparent top view
6A
3A
3B
7B
2B 7A
2A 8B
1B 8A
1A A2
4A
4B
VSS
5B
5A
6B
RESET
A1
A0
VDD
SDA
SCL
terminal 1
index area
613
514
4 15
3 16
2 17
118
7
8
9
10
11
12
24
23
22
21
20
19
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 4 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
5.2 Pin description
[1] HVQFN24 package die supply ground is connected to both the VSS pin and the exposed center pad. The
VSS pin must be connected to supply ground for proper device operation. For enhanced thermal, electrical,
and board-level performance, the exposed pad needs to be soldered to the board using a corresponding
thermal pad on the board, and for proper heat conduction through the board thermal vias need to be
incorporated in the PCB in the thermal pad region.
Table 3. Pin description
Symbol Pin Description
SO24, TSSOP24 HVQFN24
A0 1 22 address input 0
A1 2 23 address input 1
RESET 3 24 active LOW reset input
1A 4 1 input
1B 5 2 output
2A 6 3 input
2B 7 4 output
3A 8 5 input
3B 9 6 output
4A 10 7 input
4B 11 8 output
VSS 12 9[1] supply ground
5B 13 10 output
5A 14 11 input
6B 15 12 output
6A 16 13 input
7B 17 14 output
7A 18 15 input
8B 19 16 output
8A 20 17 input
A2 21 18 address input 2
SCL 22 19 serial clock line
SDA 23 20 serial data line
VDD 24 21 supply voltage
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 5 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
6. Functional description
6.1 Device addressing
Following a START condition, the bus master must output the address of the slave it is
accessing. The address of the PCA9549 is shown in Figure 5. To conserve power, no
internal pull-up resistors are incorporated on the hardware selectable address pins and
they must be pulled HIGH or LOW.
The last bit of the slave address defines the operation to be performed. When set to
logic 1 a read is selected, while a logic 0 selects a write operation.
6.2 Control register
Following the successful acknowledgement of the slave address, the bus master will send
a byte to the PCA9549, which will be stored in the Control register. If multiple bytes are
received by the PCA9549, it will save the last byte received. This register can be written
and read via the I2C-bus.
6.2.1 Control register definition
One or several bits are selected by the contents of the Control register. This register is
written after the PCA9549 has been addressed. The entire control byte is used to
determine which bit is to be selected. When a bit is selected to close, the bit will close
after the Acknowledge has been placed on the I2C-bus.
Fig 5. Slave address
002aaa962
1 1 1 0 A2 A1 A0 R/W
fixed hardware
selectable
Fig 6. Control register
002aab254
B7 B6 B5 B4 B3 B2 B1 B0
channel selection bits
(read/write)
76543210
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
bit 8
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 6 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
[1] Several bits can be enabled at the same time. For example, B7 = 0, B6 = 1, B5 = 0, B4 = 0, B3 = 1, B2 = 1,
B1 = 0, B0 = 0, means that bit 8, bit 6, bit 5, bit 2, and bit 1 are disabled and bit 7, bit 4, and bit 3 are
enabled.
6.3 RESET input
The RESET input is an active LOW signal which may be used to recover from a bus fault
condition. By asserting this signal LOW for a minimum of tw(rst)L, the PCA9549 will reset its
registers and I2C-bus state machine and will open all bits. The RESET input must be
connected to VDD through a pull-up resistor.
6.4 Power-on reset
When power is applied to VDD, an internal Power-On Reset (POR) holds the PCA9549 in
a reset state until VDD has reached VPOR. At this point, the reset condition is released and
the PCA9549 registers and I2C-bus state machine are initialized to their default states, all
zeroes causing all the bits to be open (high-impedance state).
6.5 CBT characteristic over VDD range
The bus switch is optimized at 5.0 V but can operate over the entire supply range with
lower Vo(sw) voltage and higher gate resistance.
Table 4. Control register
Write = channel selection; read = channel status.
B7 B6 B5 B4 B3 B2 B1 B0 Command
XXXXXXX0 bit 1 disabled
1 bit 1 enabled
XXXXXX0Xbit 2 disabled
1 bit 2 enabled
XXXXX0XX
bit 3 disabled
1 bit 3 enabled
XXXX0XXX
bit 4 disabled
1 bit 4 enabled
XXX0XXXX
bit 5 disabled
1 bit 5 enabled
XX0XXXXX
bit 6 disabled
1 bit 6 enabled
X0XXXXXX
bit 7 disabled
1 bit 7 enabled
0XXXXXXX
bit 8 disabled
1 bit 8 enabled
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 7 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
Figure 7 shows the voltage characteristics of the pass gate transistors (note that the
PCA9549 is only tested at the points specified in Section 9 “Static characteristics”). In
order for the PCA9549 to act as a voltage translator, the Vo(sw) voltage should be equal to,
or lower than the lowest bus voltage. For example, if the main bus was running at 5 V, and
the downstream buses were 3.3 V and 2.7 V, then Vo(sw) should be equal to or below 2.7 V
to effectively clamp the downstream bus voltages. Looking at Figure 7, we see that Vo(sw)
(maximum) will be at 2.7 V when the PCA9549 supply voltage is 3.5 V or lower so the
PCA9549 supply voltage could be set to 3.3 V. Pull-up resistors can then be used to bring
the bus voltages to their appropriate levels (see Figure 16).
(1) maximum.
(2) typical.
(3) minimum.
Fig 7. Vo(sw) voltage versus VDD
VDD (V)
2.0 5.54.53.0 4.0
002aaa964
3.0
2.0
4.0
5.0
Vo(sw)
(V)
1.0 3.5 5.02.5
(1)
(2)
(3)
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 8 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
7. Characteristics of the I2C-bus
The I2C-bus is for 2-way, 2-line communication between different ICs or modules. The two
lines are a serial data line (SDA) and a serial clock line (SCL). Both lines must be
connected to a positive supply via a pull-up resistor. Data transfer may be initiated only
when the bus is not busy.
7.1 Bit transfer
One data bit is transferred during each clock pulse. The data on the SDA line must remain
stable during the HIGH period of the clock pulse as changes in the data line at this time
will be interpreted as control signals (see Figure 8).
7.1.1 START and STOP conditions
Both data and clock lines remain HIGH when the bus is not busy. A HIGH-to-LOW
transition of the data line while the clock is HIGH is defined as the START condition (S).
A LOW-to-HIGH transition of the data line while the clock is HIGH is defined as the STOP
condition (P) (see Figure 9).
7.2 System configuration
A device generating a message is a ‘transmitter’; a device receiving is the ‘receiver’. The
device that controls the message is the ‘master’ and the devices which are controlled by
the master are the ‘slaves’ (see Figure 10).
Fig 8. Bit transfer
mba607
data line
stable;
data valid
change
of data
allowed
SDA
SCL
Fig 9. Definition of START and STOP conditions
mba608
SDA
SCL P
STOP condition
S
START condition
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 9 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
7.3 Acknowledge
The number of data bytes transferred between the START and the STOP conditions from
transmitter to receiver is not limited. Each byte of eight bits is followed by one
acknowledge bit. The acknowledge bit is a HIGH level put on the bus by the transmitter,
whereas the master generates an extra acknowledge related clock pulse.
A slave receiver which is addressed must generate an acknowledge after the reception of
each byte. Also a master must generate an acknowledge after the reception of each byte
that has been clocked out of the slave transmitter. The device that acknowledges has to
pull down the SDA line during the acknowledge clock pulse, so that the SDA line is stable
LOW during the HIGH period of the acknowledge related clock pulse; set-up and hold
times must be taken into account.
A master receiver must signal an end of data to the transmitter by not generating an
acknowledge on the last byte that has been clocked out of the slave. In this event, the
transmitter must leave the data line HIGH to enable the master to generate a STOP
condition.
Fig 10. System configuration
002aaa966
MASTER
TRANSMITTER/
RECEIVER
SLAVE
RECEIVER SLAVE
TRANSMITTER/
RECEIVER
MASTER
TRANSMITTER MASTER
TRANSMITTER/
RECEIVER
SDA
SCL
I2C-BUS
MULTIPLEXER
SLAVE
Fig 11. Acknowledgement on the I2C-bus
002aaa987
S
START
condition
9821
clock pulse for
acknowledgement
not acknowledge
acknowledge
data output
by transmitter
data output
by receiver
SCL from master
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 10 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
7.4 Bus transactions
Data is transmitted to the PCA9549 control register using the Write mode as shown in
Figure 12.
Data is read from the PCA9549 using the Read mode as shown in Figure 13.
8. Limiting values
[1] The performance capability of a high-performance integrated circuit in conjunction with its thermal
environment can create junction temperatures which are detrimental to reliability. The maximum junction
temperature of this integrated circuit should not exceed 125 °C.
Fig 12. Write control register
Fig 13. Read control register
002aac430
B7 B6 B5 B4 B3 B2 B1 B01 1 0 A2 A1 A0 0 AS 1 A P
slave address
START condition R/W acknowledge
from slave acknowledge
from slave
control register
SDA
STOP condition
002aac431
1 1 0 A2 A1 A0 1 AS 1 A P
slave address
START condition R/W acknowledge
from slave no acknowledge
from master
control register
SDA
STOP condition
last byte
B7 B6 B5 B4 B3 B2 B1 B0
Table 5. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
[1]
Symbol Parameter Conditions Min Max Unit
VDD supply voltage 0.5 +7.0 V
VIinput voltage 0.5 +7.0 V
IIinput current 20 +20 mA
IOoutput current 25 +25 mA
IDD supply current 100 +100 mA
ISS ground supply current 100 +100 mA
Ptot total power dissipation - 400 mW
Tstg storage temperature 60 +150 °C
Tamb ambient temperature operating 40 +85 °C
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 11 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
9. Static characteristics
[1] For operation between published voltage ranges, refer to the worst-case parameters in both ranges.
[2] VDD must be lowered to 0.2 V in order to reset part.
Table 6. Static characteristics at VDD = 2.3 V to 3.6 V
V
SS
= 0 V; T
amb
=
40
°
C to +85
°
C; unless otherwise specified. See Table 7 on page 12 for V
DD
= 4.5 V to 5.5 V
[1]
.
Symbol Parameter Conditions Min Typ Max Unit
Supply
VDD supply voltage 2.3 - 3.6 V
IDD supply current Operating mode; VDD = 3.6 V; no load;
VI=V
DD or VSS; fSCL = 100 kHz -2050µA
Istb standby current Standby mode; VDD = 3.6 V; no load;
VI=V
DD or VSS
- 0.1 1 µA
VPOR power-on reset voltage no load; VI=V
DD or VSS [2] - 1.6 2.1 V
Input SCL; input/output SDA
VIL LOW-level input voltage 0.5 - +0.3VDD V
VIH HIGH-level input voltage 0.7VDD -6 V
IOL LOW-level output current VOL = 0.4 V 3 - - mA
VOL = 0.6 V 6 - - mA
ILleakage current VI=V
DD or VSS 1-+1 µA
Ciinput capacitance VI=V
SS - 6 21 pF
Select inputs A0 to A2, RESET
VIL LOW-level input voltage 0.5 - +0.3VDD V
VIH HIGH-level input voltage 0.7VDD -V
DD + 0.5 V
ILI input leakage current pin at VDD or VSS 1-+1 µA
Ciinput capacitance VI=V
SS -25 pF
Pass gate
Ron ON-state resistance VDD = 3.0 V to 3.6 V; VO= 0.4 V;
IO=15mA -712
VDD = 2.3 V to 2.7 V; VO= 0.4 V;
IO=10mA -815
Vo(sw) switch output voltage Vi(sw) =V
DD = 3.3 V; Io(sw) =100 µA - 1.9 - V
Vi(sw) =V
DD = 3.0 V to 3.6 V;
Io(sw) =100 µA1.6 - 2.8 V
Vi(sw) =V
DD = 2.5 V; Io(sw) =100 µA - 1.5 - V
Vi(sw) =V
DD = 2.3 V to 2.7 V;
Io(sw) =100 µA1.0 - 2.0 V
ILleakage current VI=V
DD or VSS 1-+1 µA
Cio input/output capacitance VI=V
SS -35 pF
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 12 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
[1] For operation between published voltage ranges, refer to the worst-case parameters in both ranges.
[2] VDD must be lowered to 0.2 V in order to reset part.
Table 7. Static characteristics at VDD = 4.5 V to 5.5 V
V
SS
= 0 V; T
amb
=
40
°
C to +85
°
C; unless otherwise specified. See Table 6 on page 11 for V
DD
= 2.3 V to 3.6 V
[1]
.
Symbol Parameter Conditions Min Typ Max Unit
Supply
VDD supply voltage 4.5 - 5.5 V
IDD supply current Operating mode; VDD = 5.5 V;
no load; VI=V
DD or VSS;
fSCL = 100 kHz
- 65 100 µA
Istb standby current Standby mode; VDD = 5.5 V;
no load; VI=V
DD or VSS
- 0.6 2 µA
VPOR power-on reset voltage no load; VI=V
DD or VSS [2] - 1.7 2.1 V
Input SCL; input/output SDA
VIL LOW-level input voltage 0.5 - +0.3VDD V
VIH HIGH-level input voltage 0.7VDD -6 V
IOL LOW-level output current VOL = 0.4 V 3 - - mA
VOL = 0.6 V 6 - - mA
IIL LOW-level input current VI=V
SS 1- 1 µA
IIH HIGH-level input current VI=V
SS 1- 1 µA
Ciinput capacitance VI=V
SS - 6 21 pF
Select inputs A0 to A2, RESET
VIL LOW-level input voltage 0.5 - +0.3VDD V
VIH HIGH-level input voltage 0.7VDD -V
DD + 0.5 V
ILI input leakage current pin at VDD or VSS 1 - +50 µA
Ciinput capacitance VI=V
SS -25 pF
Pass gate
Ron ON-state resistance VDD = 4.5 V to 5.5 V; VO= 0.4 V;
IO=15mA -58
Vo(sw) switch output voltage Vi(sw) =V
DD = 5.0 V;
Io(sw) =100 µA- 3.6 - V
Vi(sw) =V
DD = 4.5 V to 5.5 V;
Io(sw) =100 µA2.6 - 4.5 V
ILleakage current VI=V
DD or VSS 10 - +10 µA
Cio input/output capacitance VI=V
SS -35 pF
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 13 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
10. Dynamic characteristics
[1] Pass gate propagation delay is calculated from the 6 typical Ron and the 50 pF load capacitance.
[2] After this period, the first clock pulse is generated.
[3] A device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the VIH(min) of the SCL signal) in order to
bridge the undefined region of the falling edge of SCL.
[4] Cb= total capacitance of one bus line in pF.
Table 8. Dynamic characteristics
Symbol Parameter Conditions Standard-mode
I2C-bus Fast-mode I2C-bus Unit
Min Max Min Max
tPD propagation delay A to B;
VDD = 4.5 V to 5.5 V - 0.25[1] - 0.25[1] ns
fSCL SCL clock frequency 0 100 0 400 kHz
tBUF bus free time between a STOP and
START condition 4.7 - 1.3 - µs
tHD;STA hold time (repeated) START condition [2] 4.0 - 0.6 - µs
tLOW LOW period of the SCL clock 4.7 - 1.3 - µs
tHIGH HIGH period of the SCL clock 4.0 - 0.6 - µs
tSU;STA set-up time for a repeated START
condition 4.7 - 0.6 - µs
tSU;STO set-up time for STOP condition 4.0 - 0.6 - µs
tHD;DAT data hold time 0[3] 3.45 0[3] 0.9 µs
tSU;DAT data set-up time 250 - 100 - ns
trrise time of both SDA and SCL
signals - 1000 20 + 0.1Cb[4] 300 ns
tffall time of both SDA and SCL signals - 300 20 + 0.1Cb[4] 300 ns
Cbcapacitive load for each bus line - 400 - 400 pF
tSP pulse width of spikes that must be
suppressed by the input filter - 50 - 50 ns
tVD;DAT data valid time HIGH-to-LOW - 1 - 1 µs
LOW-to-HIGH - 0.6 - 0.6 µs
tVD;ACK data valid acknowledge time - 1 - 1 µs
RESET
tw(rst)L LOW-level reset time 4 - 4 - ns
trst reset time SDA clear 500 - 500 - ns
tREC;STA recovery time to START condition 0 - 0 - ns
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 14 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
Fig 14. Definition of timing on the I2C-bus
tSP
tBUF
tHD;STA PP S
tLOW
tr
tHD;DAT
tf
tHIGH tSU;DAT tSU;STA
Sr
tHD;STA
tSU;STO
SDA
SCL
002aaa986
Fig 15. Definition of RESET timing
SDA
SCL
002aac314
50 %
70 %
50 % 50 %
trec(rst) tw(rst)L
RESET
START
trst
ACK or read cycle
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 15 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
11. Application information
Remark: B can also be input and A can also be output as shown in bit 8.
Fig 16. Typical application
PCA9549
1A
1B
A1
A0
VSS
SDA
SCL
RESET
VDD = 5.0 V
VDD = 5.0 V
I2C-bus/SMBus
MASTER
SDA
SCL bit 1
A2
2A
2B bit 2
3A
3B bit 3
4A
4B bit 4
5A
5B bit 5
6A
6B bit 6
7A
7B bit 7
8A
8B bit 8
002aaa995
Fig 17. Custom multiplexer or demultiplexer application
RESET
SCL
SDA
002aac279
AB C D E
ABCDE
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 16 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
12. Test information
Fig 18. 2 channel 4-to-1 multiplexer or demultiplexer
RESET
SCL
SDA
002aac280
AA AB
AB
AC AD BA BB BC BD
CL= load capacitance includes jig and probe capacitance.
RL= load resistance.
RT= termination resistance; should be equal to Zo of pulse generator.
Fig 19. Test circuit
PULSE
GENERATOR
VO
CL
50 pF
RL
002aac315
RT
VDD
DUT
2VDD
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 17 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
13. Package outline
Fig 20. SO24 package outline (SOT137-1)
UNIT A
max. A1A2A3bpcD
(1) E(1) (1)
eH
ELL
pQZ
ywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm
inches
2.65 0.3
0.1 2.45
2.25 0.49
0.36 0.32
0.23 15.6
15.2 7.6
7.4 1.27 10.65
10.00 1.1
1.0 0.9
0.4 8
0
o
o
0.25 0.1
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
Note
1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included.
1.1
0.4
SOT137-1
X
12
24
wM
θ
A
A1
A2
bp
D
HE
Lp
Q
detail X
E
Z
c
L
vMA
13
(A )
3
A
y
0.25
075E05 MS-013
pin 1 index
0.1 0.012
0.004 0.096
0.089 0.019
0.014 0.013
0.009 0.61
0.60 0.30
0.29 0.05
1.4
0.055
0.419
0.394 0.043
0.039 0.035
0.016
0.01
0.25
0.01 0.004
0.043
0.016
0.01
e
1
0 5 10 mm
scale
SO24: plastic small outline package; 24 leads; body width 7.5 mm SOT137-1
99-12-27
03-02-19
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 18 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
Fig 21. TSSOP24 package outline (SOT355-1)
UNIT A1A2A3bpcD
(1) E(2) (1)
eH
ELL
pQZywv θ
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 0.15
0.05 0.95
0.80 0.30
0.19 0.2
0.1 7.9
7.7 4.5
4.3 0.65 6.6
6.2 0.4
0.3 8
0
o
o
0.13 0.10.21
DIMENSIONS (mm are the original dimensions)
Notes
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.
0.75
0.50
SOT355-1 MO-153 99-12-27
03-02-19
0.25 0.5
0.2
wM
bp
Z
e
112
24 13
pin 1 index
θ
A
A1
A2
Lp
Q
detail X
L
(A )
3
HE
E
c
vMA
X
A
D
y
0 2.5 5 mm
scale
TSSOP24: plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT355-1
A
max.
1.1
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 19 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
Fig 22. HVQFN24 package outline (SOT616-1)
0.51 0.2
A1Eh
b
UNIT ye
REFERENCES
OUTLINE
VERSION EUROPEAN
PROJECTION ISSUE DATE
IEC JEDEC JEITA
mm 4.1
3.9
Dh
2.25
1.95
y1
4.1
3.9 2.25
1.95
e1
2.5
e2
2.5
0.30
0.18
c
0.05
0.00 0.05 0.1
DIMENSIONS (mm are the original dimensions)
SOT616-1 MO-220 - - -- - -
0.5
0.3
L
0.1
v
0.05
w
0 2.5 5 mm
scale
SOT616-1
HVQFN24: plastic thermal enhanced very thin quad flat package; no leads;
24 terminals; body 4 x 4 x 0.85 mm
A(1)
max.
AA1c
detail X
y
y1C
e
L
Eh
Dh
e
e1
b
712
24 19
18
13
6
1
X
D
E
C
BA
e2
01-08-08
02-10-22
terminal 1
index area
terminal 1
index area
AC
CB
vM
wM
1/2 e
1/2 e
E(1)
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
D(1)
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 20 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
14. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note
AN10365 “Surface mount reflow
soldering description”
.
14.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
14.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
Through-hole components
Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
14.3 Wave soldering
Key characteristics in wave soldering are:
Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
Solder bath specifications, including temperature and impurities
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 21 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
14.4 Reflow soldering
Key characteristics in reflow soldering are:
Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 23) than a SnPb process, thus
reducing the process window
Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 9 and 10
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 23.
Table 9. SnPb eutectic process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350
< 2.5 235 220
2.5 220 220
Table 10. Lead-free process (from J-STD-020C)
Package thickness (mm) Package reflow temperature (°C)
Volume (mm3)
< 350 350 to 2000 > 2000
< 1.6 260 260 260
1.6 to 2.5 260 250 245
> 2.5 250 245 245
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 22 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
For further information on temperature profiles, refer to Application Note
AN10365
“Surface mount reflow soldering description”
.
15. Abbreviations
MSL: Moisture Sensitivity Level
Fig 23. Temperature profiles for large and small components
001aac844
temperature
time
minimum peak temperature
= minimum soldering temperature
maximum peak temperature
= MSL limit, damage level
peak
temperature
Table 11. Abbreviations
Acronym Description
CBT Cross Bar Technology
CDM Charged-Device Model
DUT Device Under Test
ESD ElectroStatic Discharge
HBM Human Body Model
I2C-bus Inter-Integrated Circuit bus
MM Machine Model
PCB Printed-Circuit Board
SMBus System Management Bus
TTL Transistor-Transistor Logic
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 23 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
16. Revision history
Table 12. Revision history
Document ID Release date Data sheet status Change notice Supersedes
PCA9549_2 20090713 Product data sheet - PCA9549_1
Modifications: The format of this data sheet has been redesigned to comply with the new identity
guidelines of NXP Semiconductors.
Legal texts have been adapted to the new company name where appropriate.
Table 8 “Dynamic characteristics”:
Symbol tf: changed Unit from “µs” to “ns”.
Symbol Cb: changed Unit from “µs” to “pF”.
Updated soldering information.
PCA9549_1 20060711 Product data sheet - -
PCA9549_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 13 July 2009 24 of 25
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
17. Legal information
17.1 Data sheet status
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
17.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
17.3 Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, NXP Semiconductors does not give any representations or
warranties, expressed or implied, as to the accuracy or completeness of such
information and shall have no liability for the consequences of use of such
information.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) may cause permanent
damage to the device. Limiting values are stress ratings only and operation of
the device at these or any other conditions above those given in the
Characteristics sections of this document is not implied. Exposure to limiting
values for extended periods may affect device reliability.
Terms and conditions of sale — NXP Semiconductors products are sold
subject to the general terms and conditions of commercial sale, as published
at http://www.nxp.com/profile/terms, including those pertaining to warranty,
intellectual property rights infringement and limitation of liability, unless
explicitly otherwise agreed to in writing by NXP Semiconductors. In case of
any inconsistency or conflict between information in this document and such
terms and conditions, the latter will prevail.
No offer to sell or license — Nothing in this document may be interpreted
or construed as an offer to sell products that is open for acceptance or the
grant, conveyance or implication of any license under any copyrights, patents
or other industrial or intellectual property rights.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from national authorities.
17.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
18. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Document status[1][2] Product status[3] Definition
Objective [short] data sheet Development This document contains data from the objective specification for product development.
Preliminary [short] data sheet Qualification This document contains data from the preliminary specification.
Product [short] data sheet Production This document contains the product specification.
NXP Semiconductors PCA9549
Octal bus switch with individually I2C-bus controlled enables
© NXP B.V. 2009. All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 13 July 2009
Document identifier: PCA9549_2
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
19. Contents
1 General description. . . . . . . . . . . . . . . . . . . . . . 1
2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Ordering information. . . . . . . . . . . . . . . . . . . . . 2
3.1 Ordering options. . . . . . . . . . . . . . . . . . . . . . . . 2
4 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2
5 Pinning information. . . . . . . . . . . . . . . . . . . . . . 3
5.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
6 Functional description . . . . . . . . . . . . . . . . . . . 5
6.1 Device addressing . . . . . . . . . . . . . . . . . . . . . . 5
6.2 Control register. . . . . . . . . . . . . . . . . . . . . . . . . 5
6.2.1 Control register definition . . . . . . . . . . . . . . . . . 5
6.3 RESET input. . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.4 Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.5 CBT characteristic over VDD range. . . . . . . . . . 6
7 Characteristics of the I2C-bus. . . . . . . . . . . . . . 8
7.1 Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.1.1 START and STOP conditions . . . . . . . . . . . . . . 8
7.2 System configuration . . . . . . . . . . . . . . . . . . . . 8
7.3 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.4 Bus transactions. . . . . . . . . . . . . . . . . . . . . . . 10
8 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 10
9 Static characteristics. . . . . . . . . . . . . . . . . . . . 11
10 Dynamic characteristics . . . . . . . . . . . . . . . . . 13
11 Application information. . . . . . . . . . . . . . . . . . 15
12 Test information. . . . . . . . . . . . . . . . . . . . . . . . 16
13 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 17
14 Soldering of SMD packages . . . . . . . . . . . . . . 20
14.1 Introduction to soldering . . . . . . . . . . . . . . . . . 20
14.2 Wave and reflow soldering . . . . . . . . . . . . . . . 20
14.3 Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 20
14.4 Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . 21
15 Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . 22
16 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 23
17 Legal information. . . . . . . . . . . . . . . . . . . . . . . 24
17.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 24
17.2 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
17.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 24
17.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 24
18 Contact information. . . . . . . . . . . . . . . . . . . . . 24
19 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25