SD0

13

11

3

5

9

6

10

4

8

2

7

1

SC0

TCA9543A

V

= 1.65 V to 5.5 V

DPU0

V

= 1.65 V to 5.5 V

DPU1

Channel 0

Channel 1

SDA

VCC

SCL

I C/SMBus

2

Master

V

= 2.5 V

CC

V

= 1.65 V to 5.5 V

DPUM

INT

INT0

SD1

SC1

INT1

RESET

A1

GND

A0

SDA

SCL

12

17

TCA9543A

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SCPS206B – MARCH 2014 – REVISED NOVEMBER 2019

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9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

Applications of the TCA9543A will contain an I2C (or SMBus) master device and up to two I2C slave devices. The

downstream channels are ideally used to resolve I2C slave address conflicts. For example, if two identical digital

temperature sensors are needed in the application, one sensor can be connected at each channel: 0 and 1.

When the temperature at a specific location needs to be read, the appropriate channel can be enabled and the

other channel switched off, the data can be retrieved, and the I2C master can move on and read the next

channel.

In an application where the I2C bus will contain many additional slave devices that do not result in I2C slave

address conflicts, these slave devices can be connected to any desired channel to distribute the total bus

capacitance across both channels. If both switches will be enabled simultaneously, additional design

requirements must be considered (See Design Requirements and Detailed Design Procedure).

9.2 Typical Application

A typical application of the TCA9543A contains anywhere from 1 to 3 separate data pull-up voltages, VDPUX , one

for the master device (VDPUM) and one for each of the selectable slave channels (VDPU0 and VDPU1). In the event

where the master device and both slave devices operate at the same voltage, then the pass voltage, Vpass =

VDPUX. Once the maximum Vpass is known, Vcc can be selected easily using Figure 17. In an application where

voltage translation is necessary, additional design requirements must be considered (See Design Requirements).

Figure 16 shows an application in which the TCA9543A can be used.

Figure 16. Typical Application Schematic

9.2.1 Design Requirements

The pull-up resistors on the INT1-INT0 terminals in the application schematic are not required in all applications.

If the device generating the interrupt has an open-drain output structure or can be tri-stated, a pull-up resistor is

required. If the device generating the interrupt has a push-pull output structure and cannot be tri-stated, a pull-up

resistor is not required. The interrupt inputs should not be left floating in the application.