1 Features

1. 1-of-2 Bidirectional Translating Switches

. I2C Bus and SMBus Compatible

. Two active-low interrupt inputs

. Active-low interrupt output

. Active-low reset input

. Two address pins allowing up to four TCA9543A

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 1.65-V

to 5.5-V

. 5.5-V Tolerant inputs

. 0 to 400-kHz Clock frequency

. Latch-up Performance exceeds 100-mA Per

JESD78

. ESD Protection exceeds JESD 22

. 4000-V Human-body model (A114-A)

. 1500-V Charged-device model (C101)

2 Applications

• Servers

• Routers (telecom switching equipment)

• Factory automation

• Products with I2C slave address conflicts (multiple,

identical temp sensors)

3 Description

The TCA9543A is a dual bidirectional translating

switch controlled by the I2C bus. The SCL/SDA

upstream pair fans out to two downstream pairs, or

channels. Either individual SCn/SDn channel or both

channels can be selected, determined by the

contents of the programmable control register. Two

interrupt inputs (INT1–INT0), one for each of the

downstream pairs, are provided. One interrupt output

(INT) acts as an AND of the two interrupt inputs.

An active-low reset (RESET) input allows the

TCA9543A to recover from a situation where one of

the downstream I2C buses is stuck in a low state.

Pulling RESET low resets the I2C state machine and

causes both of the channels to be deselected, as

does the internal power-on reset function.

The pass gates of the switches are constructed such

that the VCC terminal can be used to limit the

maximum high voltage, which will be passed by the

TCA9543A. This allows the use of different bus

voltages on each pair, so that 1.8-V, 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 terminals are 5.5-V tolerant.