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PCA9548A
8-channel I2C-bus switch with reset
Rev. 03 -- 7 July 2009 Product data sheet
1. General description
The PCA9548A is an octal bidirectional translating switch controlled via the I2C-bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individual SCx/SDx channel or combination of channels can be selected, determined by the contents of the programmable control register. An active LOW reset input allows the PCA9548A to recover from a situation where one of the downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-bus state machine and causes all the channels to be deselected as does the internal Power-on reset function. The pass gates of the switches are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9548A. This allows the use of different bus voltages on each pair, so that 1.8 V or 2.5 V or 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5 V tolerant.
2. Features
I I I I I I I I I I I I I I I 1-of-8 bidirectional translating switches I2C-bus interface logic; compatible with SMBus standards Active LOW reset input 3 address pins allowing up to 8 devices on the I2C-bus Channel selection via I2C-bus, in any combination Power-up with all switch channels deselected Low Ron switches Allows voltage level translation between 1.8 V, 2.5 V, 3.3 V and 5 V buses No glitch on power-up Supports hot insertion Low standby current Operating power supply voltage range of 2.3 V to 5.5 V 5 V tolerant inputs 0 Hz to 400 kHz clock frequency ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101 I Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA I Three packages offered: SO24, TSSOP24, and HVQFN24
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
3. Ordering information
Table 1. Ordering information Package Name PCA9548ABS PCA9548AD PCA9548APW HVQFN24 SO24 TSSOP24 Description Version plastic thermal enhanced very thin quad flat package; SOT616-1 no leads; 24 terminals; body 4 x 4 x 0.85 mm plastic small outline package; 24 leads; body width 7.5 mm plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT137-1 SOT355-1 Type number
3.1 Ordering options
Table 2. Ordering options Topside mark 548A PCA9548AD PCA9548A Temperature range -40 C to +85 C -40 C to +85 C -40 C to +85 C Type number PCA9548ABS PCA9548AD PCA9548APW
PCA9548A_3
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Product data sheet
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
4. Block diagram
PCA9548A
SC0 SC1 SC2 SC3 SC4 SC5 SC6 SC7 SD0 SD1 SD2 SD3 SD4 SD5 SD6 SD7
VSS VDD RESET
SWITCH CONTROL LOGIC
RESET CIRCUIT
SCL SDA
INPUT FILTER
A0 I2C-BUS CONTROL A1 A2
002aab202
Fig 1.
Block diagram of PCA9548A
PCA9548A_3
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Product data sheet
Rev. 03 -- 7 July 2009
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
5. Pinning information
5.1 Pinning
A0 A1 RESET SD0 SC0 SD1 SC1 SD2 SC2
1 2 3 4 5 6 7 8 9
24 VDD 23 SDA 22 SCL 21 A2 20 SC7 19 SD7 18 SC6 17 SD6 16 SC5 15 SD5 14 SC4 13 SD4
002aab199
A0 A1 RESET SD0 SC0 SD1 SC1 SD2 SC2
1 2 3 4 5 6 7 8 9
24 VDD 23 SDA 22 SCL 21 A2 20 SC7 19 SD7 18 SC6 17 SD6 16 SC5 15 SD5 14 SC4 13 SD4
002aab200
PCA9548AD
PCA9548APW
SD3 10 SC3 11 VSS 12
SD3 10 SC3 11 VSS 12
Fig 2.
Pin configuration for SO24
24 RESET
Fig 3.
Pin configuration for TSSOP24
20 SDA
23 A1
SD0 SC0 SD1 SC1 SD2 SC2
1 2 3 4 5 6 SD4 10 SC4 11 SD5 12 7 8 9
22 A0
terminal 1 index area
19 SCL 18 A2 17 SC7 16 SD7 15 SC6 14 SD6 13 SC5
002aab201
PCA9548ABS
SD3
SC3
Transparent top view
Fig 4.
Pin configuration for HVQFN24 (transparent top view)
PCA9548A_3
VSS
21 VDD
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
5.2 Pin description
Table 3. Symbol A0 A1 RESET SD0 SC0 SD1 SC1 SD2 SC2 SD3 SC3 VSS SD4 SC4 SD5 SC5 SD6 SC6 SD7 SC7 A2 SCL SDA VDD
[1]
Pin description Pin SO24, TSSOP24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 HVQFN24 22 23 24 1 2 3 4 5 6 7 8 9[1] 10 11 12 13 14 15 16 17 18 19 20 21 address input 0 address input 1 active LOW reset input serial data 0 serial clock 0 serial data 1 serial clock 1 serial data 2 serial clock 2 serial data 3 serial clock 3 supply ground serial data 4 serial clock 4 serial data 5 serial clock 5 serial data 6 serial clock 6 serial data 7 serial clock 7 address input 2 serial clock line serial data line supply voltage Description
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.
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
6. Functional description
Refer to Figure 1 "Block diagram of PCA9548A".
6.1 Device address
Following a START condition, the bus master must output the address of the slave it is accessing. The address of the PCA9548A 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.
1
1 fixed
1
0
A2
A1
A0 R/W
hardware selectable
002aab189
Fig 5.
Slave address
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 PCA9548A, which will be stored in the control register. If multiple bytes are received by the PCA9548A, it will save the last byte received. This register can be written and read via the I2C-bus.
channel selection bits (read/write) 7 B7 6 B6 5 B5 4 B4 3 B3 2 B2 1 B1 0 B0 channel 0 channel 1 channel 2 channel 3 channel 4 channel 5 channel 6 channel 7
002aab204
Fig 6.
Control register
PCA9548A_3
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Product data sheet
Rev. 03 -- 7 July 2009
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
6.2.1 Control register definition
One or several SCx/SDx downstream pair, or channel, is selected by the contents of the control register. This register is written after the PCA9548A has been addressed. The 2 LSBs of the control byte are used to determine which channel is to be selected. When a channel is selected, the channel will become active after a STOP condition has been placed on the I2C-bus. This ensures that all SCx/SDx lines will be in a HIGH state when the channel is made active, so that no false conditions are generated at the time of connection.
Table 4. B7 X X X X X X X 0 1 B6 X X X X X X 0 1 X Control register: Write--channel selection; Read--channel status B5 X X X X X 0 1 X X B4 X X X X 0 1 X X X B3 X X X 0 1 X X X X B2 X X 0 1 X X X X X B1 X 0 1 X X X X X X B0 0 1 X X X X X X X Command channel 0 disabled channel 0 enabled channel 1 disabled channel 1 enabled channel 2 disabled channel 2 enabled channel 3 disabled channel 3 enabled channel 4 disabled channel 4 enabled channel 5 disabled channel 5 enabled channel 6 disabled channel 6 enabled channel 7 disabled channel 7 enabled
Remark: Multiple channels can be enabled at the same time. Example: B7 = 0, B6 = 1, B5 = 0, B4 = 0, B3 = 1, B2 = 1, B1 = 0, B0 = 0, means that channels 7, 5, 4, 1 and 0 are disabled and channels 6, 3, and 2 are enabled. Care should be taken not to exceed the maximum bus capacitance. Default condition is all zeroes.
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 PCA9548A will reset its register and I2C-bus state machine and will deselect all channels. 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 PCA9548A in a reset condition until VDD has reached VPOR. At this point, the reset condition is released and the PCA9548A register and I2C-bus state machine are initialized to their default states (all zeroes) causing all the channels to be deselected. Thereafter, VDD must be lowered below 0.2 V to reset the device.
PCA9548A_3
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Product data sheet
Rev. 03 -- 7 July 2009
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PCA9548A
8-channel I2C-bus switch with reset
6.5 Voltage translation
The pass gate transistors of the PCA9548A are constructed such that the VDD voltage can be used to limit the maximum voltage that will be passed from one I2C-bus to another.
5.0 Vo(sw) (V) 4.0
(1)
002aaa964
3.0
(2) (3)
2.0
1.0 2.0
2.5
3.0
3.5
4.0
4.5
5.5 5.0 VDD (V)
(1) maximum (2) typical (3) minimum
Fig 7.
Pass gate voltage versus supply voltage
Figure 7 shows the voltage characteristics of the pass gate transistors (note that the PCA9548A is only tested at the points specified in Section 10 "Static characteristics" of this data sheet). In order for the PCA9548A 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)(max) will be at 2.7 V when the PCA9548A supply voltage is 3.5 V or lower, so the PCA9548A 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 14). More Information can be found in Application Note AN262: PCA954X family of I2C/SMBus multiplexers and switches.
PCA9548A_3
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Product data sheet
Rev. 03 -- 7 July 2009
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PCA9548A
8-channel I2C-bus switch with reset
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 when connected to the output stages of a device. 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).
SDA
SCL data line stable; data valid change of data allowed
mba607
Fig 8.
Bit transfer
7.2 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).
SDA
SCL S START condition P STOP condition
mba608
Fig 9.
Definition of START and STOP conditions
7.3 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).
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
SDA SCL MASTER TRANSMITTER/ RECEIVER SLAVE RECEIVER SLAVE TRANSMITTER/ RECEIVER MASTER TRANSMITTER MASTER TRANSMITTER/ RECEIVER I2C-BUS MULTIPLEXER
SLAVE
002aaa966
Fig 10. System configuration
7.4 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.
data output by transmitter not acknowledge data output by receiver acknowledge SCL from master S START condition 1 2 8 clock pulse for acknowledgement
002aaa987
9
Fig 11. Acknowledgement on the I2C-bus
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
7.5 Bus transactions
Data is transmitted to the PCA9548A control register using the Write mode as shown in Figure 12.
slave address SDA S 1 1 1 0 A2 A1 A0 0 A B7 B6
control register B5 B4 B3 B2 B1 B0 A P
START condition
R/W
acknowledge from slave
acknowledge from slave STOP condition
002aab205
Fig 12. Write control register
Data is read from PCA9548A using the Read mode as shown in Figure 13.
slave address SDA S 1 1 1 0 A2 A1 A0 1 A B7 B6
control register B5 B4 B3 B2 B1
last byte
B0
NA
P
START condition
R/W
acknowledge from slave
no acknowledge from master STOP condition
002aab206
Fig 13. Read control register
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
8. Application design-in information
VDD = 2.7 V to 5.5 V VDD = 3.3 V V = 2.7 V to 5.5 V
SDA SCL
SDA SCL
SD0 SC0
channel 0
V = 2.7 V to 5.5 V RESET I2C/SMBus master SD1 SC1 V = 2.7 V to 5.5 V
channel 1
SD2 SC2
channel 2
V = 2.7 V to 5.5 V
SD3 SC3
channel 3
PCA9548A
V = 2.7 V to 5.5 V
SD4 SC4
channel 4
V = 2.7 V to 5.5 V
SD5 SC5
channel 5
V = 2.7 V to 5.5 V
SD6 SC6
channel 6
V = 2.7 V to 5.5 V A2 A1 A0 VSS SD7 SC7
002aab203
channel 7
Fig 14. Typical application
PCA9548A_3
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Product data sheet
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
9. Limiting values
Table 5. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to VSS (ground = 0 V).[1] Symbol VDD VI II IO IDD ISS Ptot Tstg Tamb
[1]
Parameter supply voltage input voltage input current output current supply current ground supply current total power dissipation storage temperature ambient temperature
Conditions
Min -0.5 -0.5 -60
Max +7.0 +7.0 20 25 100 100 400 +150 +85
Unit V V mA mA mA mA mW C C
operating
-40
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.
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
10. Static characteristics
Table 6. Static characteristics at VDD = 2.3 V to 3.6 V VSS = 0 V; Tamb = -40 C to +85 C; unless otherwise specified. See Table 7 on page 15 for VDD = 4.5 V to 5.5 V.[1] Symbol Supply VDD IDD Istb VPOR VIL VIH IOL IL Ci VIL VIH ILI Ci Pass gate Ron ON-state resistance VDD = 3.0 V to 3.6 V; VO = 0.4 V; IO = 15 mA VDD = 2.3 V to 2.7 V; VO = 0.4 V; IO = 10 mA Vo(sw) switch output voltage Vi(sw) = VDD = 3.3 V; Io(sw) = -100 A Vi(sw) = VDD = 3.0 V to 3.6 V; Io(sw) = -100 A Vi(sw) = VDD = 2.5 V; Io(sw) = -100 A Vi(sw) = VDD = 2.3 V to 2.7 V; Io(sw) = -100 A IL Cio
[1] [2]
Parameter supply voltage supply current standby current power-on reset voltage LOW-level input voltage HIGH-level input voltage LOW-level output current leakage current input capacitance LOW-level input voltage HIGH-level input voltage input leakage current input capacitance
Conditions
Min 2.3
Typ 30 0.1 1.6 6 9 15 2 11 16 1.9 1.5 3
Max 3.6 50 1 2.1 +0.3VDD 6 +1 21 +0.3VDD VDD + 0.5 +1 5 30 55 2.8 2.0 +1 5
Unit V A A V V V mA mA A pF V V A pF V V V V A pF
operating mode; VDD = 3.6 V; no load; VI = VDD or VSS; fSCL = 100 kHz standby mode; VDD = 3.6 V; no load; VI = VDD or VSS no load; VI = VDD or VSS
[2]
-0.5 0.7VDD
Input SCL; input/output SDA
VOL = 0.4 V VOL = 0.6 V VI = VDD or VSS VI = VSS
3 6 -1 -0.5 0.7VDD
Select inputs A0 to A2, RESET
pin at VDD or VSS VI = VSS
-1 5 7 1.6 1.1 -1 -
leakage current input/output capacitance
VI = VDD or VSS VI = VSS
For operation between published voltage ranges, refer to the worst-case parameter in both ranges. VDD must be lowered to 0.2 V in order to reset part.
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
Table 7. Static characteristics at VDD = 4.5 V to 5.5 V VSS = 0 V; Tamb = -40 C to +85 C; unless otherwise specified. See Table 6 on page 14 for VDD = 2.3 V to 3.6 V.[1] Symbol Supply VDD IDD supply voltage supply current operating mode; VDD = 5.5 V; no load; VI = VDD or VSS; fSCL = 100 kHz standby mode; VDD = 5.5 V; no load; VI = VDD or VSS no load; VI = VDD or VSS
[2]
Parameter
Conditions
Min 4.5 -
Typ 65
Max 5.5 100
Unit V A
Istb VPOR VIL VIH IOL IIL IIH Ci VIL VIH ILI Ci Pass gate Ron Vo(sw)
standby current power-on reset voltage LOW-level input voltage HIGH-level input voltage LOW-level output current LOW-level input current HIGH-level input current input capacitance LOW-level input voltage HIGH-level input voltage input leakage current input capacitance ON-state resistance switch output voltage
-0.5 0.7VDD
0.2 1.7 15 2 9 3.6 3
1 2.1 +0.3VDD 6 +1 +1 21 +0.3VDD VDD + 0.5 +1 5 24 4.5 +1 5
A V V V mA mA A A pF V V A pF V V A pF
Input SCL; input/output SDA
VOL = 0.4 V VOL = 0.6 V VI = VSS VI = VDD VI = VSS
3 6 -1 -1 -0.5 0.7VDD
Select inputs A0 to A2, RESET
pin at VDD or VSS VI = VSS VDD = 4.5 V to 5.5 V; VO = 0.4 V; IO = 15 mA Vi(sw) = VDD = 5.0 V; Io(sw) = -100 A Vi(sw) = VDD = 4.5 V to 5.5 V; Io(sw) = -100 A
-1 4 2.6 -1 -
IL Cio
[1] [2]
leakage current input/output capacitance
VI = VDD or VSS VI = VSS
For operation between published voltage ranges, refer to the worst-case parameter in both ranges. VDD must be lowered to 0.2 V in order to reset part.
PCA9548A_3
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
11. Dynamic characteristics
Table 8. Symbol Dynamic characteristics Parameter Conditions Standard-mode I2C-bus Min tPD fSCL tBUF tHD;STA tLOW tHIGH tSU;STA tSU;STO tHD;DAT tSU;DAT tr tf Cb tSP tVD;DAT tVD;ACK RESET tw(rst)L trst tREC;STA
[1] [2] [3] [4] [5]
Fast-mode I2C-bus Min 0 1.3 0.6 1.3 0.6 0.6 0.6 0[3] 100 20 + 0.1Cb[4] 20 + 0.1Cb[4] 4 500 0 Max 0.3[1] 400 0.9 300 300 400 50 1 0.6 1 -
Unit
Max 0.3[1] 100 3.45 1000 300 400 50 1 0.6 1 -
propagation delay SCL clock frequency bus free time between a STOP and START condition hold time (repeated) START condition LOW period of the SCL clock HIGH period of the SCL clock set-up time for a repeated START condition set-up time for STOP condition data hold time data set-up time rise time of both SDA and SCL signals fall time of both SDA and SCL signals capacitive load for each bus line pulse width of spikes that must be suppressed by the input filter data valid time data valid acknowledge time LOW-level reset time reset time recovery time to START condition
from SDA to SDx, or SCL to SCx
0 4.7
[2]
ns kHz s s s s s s s ns ns ns pF ns s s s ns ns ns
4.0 4.7 4.0 4.7 4.0 0[3] 250 -
HIGH-to-LOW LOW-to-HIGH
[5] [5]
4
SDA clear
500 0
Pass gate propagation delay is calculated from the 20 typical Ron and the 15 pF load capacitance. After this period, the first clock pulse is generated. 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. Cb = total capacitance of one bus line in pF. Measurements taken with 1 k pull-up resistor and 50 pF load.
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Product data sheet
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PCA9548A
8-channel I2C-bus switch with reset
SDA tBUF tLOW SCL tr tf tHD;STA tSP
tHD;STA P S tHD;DAT tHIGH tSU;DAT Sr
tSU;STA
tSU;STO P
002aaa986
Fig 15. Definition of timing on the I2C-bus
START SCL
ACK or read cycle
SDA 30 % trst
RESET
50 % tREC;STA
50 %
50 % tw(rst)L
002aac549
Fig 16. Definition of RESET timing
protocol
START condition (S) tSU;STA
bit 7 MSB (A7) tLOW tHIGH
bit 6 (A6)
bit 0 (R/W)
acknowledge (A)
STOP condition (P)
1/f
SCL
SCL tBUF tr tf
SDA
tHD;STA
tSU;DAT
tHD;DAT
tVD;DAT
tVD;ACK
tSU;STO
002aab175
Fig 17. I2C-bus timing diagram
PCA9548A_3
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Product data sheet
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
12. Package outline
SO24: plastic small outline package; 24 leads; body width 7.5 mm SOT137-1
D
E
A X
c y HE vMA
Z 24 13
Q A2 A1 pin 1 index Lp L 1 e bp 12 wM detail X (A 3) A
0
5 scale
10 mm
DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT mm inches A max. 2.65 0.1 A1 0.3 0.1 A2 2.45 2.25 A3 0.25 0.01 bp 0.49 0.36 c 0.32 0.23 D (1) 15.6 15.2 0.61 0.60 E (1) 7.6 7.4 0.30 0.29 e 1.27 0.05 HE 10.65 10.00 L 1.4 Lp 1.1 0.4 Q 1.1 1.0 0.043 0.039 v 0.25 0.01 w 0.25 0.01 y 0.1 Z
(1)
0.9 0.4
0.012 0.096 0.004 0.089
0.019 0.013 0.014 0.009
0.419 0.043 0.055 0.394 0.016
0.035 0.004 0.016
8 o 0
o
Note 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. OUTLINE VERSION SOT137-1 REFERENCES IEC 075E05 JEDEC MS-013 JEITA EUROPEAN PROJECTION
ISSUE DATE 99-12-27 03-02-19
Fig 18. Package outline SOT137-1 (SO24)
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Product data sheet
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NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
TSSOP24: plastic thin shrink small outline package; 24 leads; body width 4.4 mm
SOT355-1
D
E
A
X
c y HE vMA
Z
24
13
Q A2 pin 1 index A1 (A 3) A
Lp L
1
e bp
12
wM detail X
0
2.5 scale
5 mm
DIMENSIONS (mm are the original dimensions) UNIT mm A max. 1.1 A1 0.15 0.05 A2 0.95 0.80 A3 0.25 bp 0.30 0.19 c 0.2 0.1 D (1) 7.9 7.7 E (2) 4.5 4.3 e 0.65 HE 6.6 6.2 L 1 Lp 0.75 0.50 Q 0.4 0.3 v 0.2 w 0.13 y 0.1 Z (1) 0.5 0.2 8o 0o
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. OUTLINE VERSION SOT355-1 REFERENCES IEC JEDEC MO-153 JEITA EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-19
Fig 19. Package outline SOT355-1 (TSSOP24)
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Product data sheet
Rev. 03 -- 7 July 2009
19 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
HVQFN24: plastic thermal enhanced very thin quad flat package; no leads; 24 terminals; body 4 x 4 x 0.85 mm
SOT616-1
D
B
A
terminal 1 index area A A1 E c
detail X
e1
1/2 e
C b 12 vMCAB wMC 13 e y1 C y
e 7 L 6
Eh
1/2 e
e2
1
18
terminal 1 index area
24 Dh 0
19 X 2.5 scale 5 mm
DIMENSIONS (mm are the original dimensions) UNIT mm A(1) max. 1 A1 0.05 0.00 b 0.30 0.18 c 0.2 D (1) 4.1 3.9 Dh 2.25 1.95 E (1) 4.1 3.9 Eh 2.25 1.95 e 0.5 e1 2.5 e2 2.5 L 0.5 0.3 v 0.1 w 0.05 y 0.05 y1 0.1
Note 1. Plastic or metal protrusions of 0.075 mm maximum per side are not included. OUTLINE VERSION SOT616-1 REFERENCES IEC --JEDEC MO-220 JEITA --EUROPEAN PROJECTION ISSUE DATE 01-08-08 02-10-22
Fig 20. Package outline SOT616-1 (HVQFN24)
PCA9548A_3 (c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
20 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
13. 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".
13.1 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.
13.2 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
13.3 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
PCA9548A_3 (c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
21 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
13.4 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 21) 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
Table 9. SnPb eutectic process (from J-STD-020C) Package reflow temperature (C) Volume (mm3) < 350 < 2.5 2.5 Table 10. 235 220 Lead-free process (from J-STD-020C) Package reflow temperature (C) Volume (mm3) < 350 < 1.6 1.6 to 2.5 > 2.5 260 260 250 350 to 2000 260 250 245 > 2000 260 245 245 350 220 220
Package thickness (mm)
Package thickness (mm)
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 21.
PCA9548A_3
(c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
22 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
temperature
maximum peak temperature = MSL limit, damage level
minimum peak temperature = minimum soldering temperature
peak temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 21. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365 "Surface mount reflow soldering description".
14. Abbreviations
Table 11. Acronym CDM ESD HBM IC I2C-bus I/O LSB MM MSB PCB POR SMBus Abbreviations Description Charged Device Model ElectroStatic Discharge Human Body Model Integrated Circuit Inter-Integrated Circuit bus Input/Output Least Significant Bit Machine Model Most Significant Bit Printed-Circuit Board Power-On Reset System Management Bus
PCA9548A_3
(c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
23 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
15. Revision history
Table 12. Revision history Release date 20090707 Data sheet status Product data sheet Change notice Supersedes PCA9548A_2 Document ID PCA9548_3 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 "s" to "ns" - Symbol Cb: changed Unit from "s" to "pF"
*
PCA9548_2 (9397 750 14726) PCA9548A_1 (9397 750 13297)
Updated soldering information. Product data sheet Product data sheet PCA9548A_1 -
20060925 20050415
PCA9548A_3
(c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
24 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
16. Legal information
16.1 Data sheet status
Document status[1][2] Objective [short] data sheet Preliminary [short] data sheet Product [short] data sheet
[1] [2] [3]
Product status[3] Development Qualification Production
Definition This document contains data from the objective specification for product development. This document contains data from the preliminary specification. This document contains the product specification.
Please consult the most recently issued document before initiating or completing a design. The term `short data sheet' is explained in section "Definitions". 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.
16.2 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.
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.
16.3 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
16.4 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.
17. Contact information
For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com
PCA9548A_3
(c) NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 -- 7 July 2009
25 of 26
NXP Semiconductors
PCA9548A
8-channel I2C-bus switch with reset
18. Contents
1 2 3 3.1 4 5 5.1 5.2 6 6.1 6.2 6.2.1 6.3 6.4 6.5 7 7.1 7.2 7.3 7.4 7.5 8 9 10 11 12 13 13.1 13.2 13.3 13.4 14 15 16 16.1 16.2 16.3 16.4 17 18 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pinning information . . . . . . . . . . . . . . . . . . . . . . 4 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5 Functional description . . . . . . . . . . . . . . . . . . . 6 Device address . . . . . . . . . . . . . . . . . . . . . . . . . 6 Control register . . . . . . . . . . . . . . . . . . . . . . . . . 6 Control register definition . . . . . . . . . . . . . . . . . 7 RESET input . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 7 Voltage translation . . . . . . . . . . . . . . . . . . . . . . 8 Characteristics of the I2C-bus. . . . . . . . . . . . . . 9 Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 START and STOP conditions . . . . . . . . . . . . . . 9 System configuration . . . . . . . . . . . . . . . . . . . . 9 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . 10 Bus transactions . . . . . . . . . . . . . . . . . . . . . . . 11 Application design-in information . . . . . . . . . 12 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 13 Static characteristics. . . . . . . . . . . . . . . . . . . . 14 Dynamic characteristics . . . . . . . . . . . . . . . . . 16 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 18 Soldering of SMD packages . . . . . . . . . . . . . . 21 Introduction to soldering . . . . . . . . . . . . . . . . . 21 Wave and reflow soldering . . . . . . . . . . . . . . . 21 Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 21 Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 22 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 24 Legal information. . . . . . . . . . . . . . . . . . . . . . . 25 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 25 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Contact information. . . . . . . . . . . . . . . . . . . . . 25 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Please be aware that important notices concerning this document and the product(s) described herein, have been included in section `Legal information'.
(c) 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: 7 July 2009 Document identifier: PCA9548A_3

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