1 Features

1. 1-of-4 Bidirectional Translating Switches

. I2C Bus and SMBus Compatible

. Four Active-Low Interrupt Inputs

. Active-Low Interrupt Output

. Three Address Pins, Allowing up to Eight

TCA9544A Devices on the I2C Bus

. Channel Selection Via I2C Bus

. 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

JESD 78

. 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 (For

Example, Multiple, Identical Temp Sensors)

3 Description

The TCA9544A is a 4-channel, bidirectional

translating I2C Muliplexer. The master SCL/SDA

signal pair is directed to one of the four channels of

slave devices, SC0/SD0-SC3/SD3. Four interrupt

inputs (INT3–INT0), one for each of the downstream

pairs, are provided. One interrupt output (INT) acts as

an AND of the four interrupt inputs.

A power-on reset function returns the registers to

their default state and initializes the I2C state

machine, with all channels deselected.

The pass gates of the switches are constructed such

that the VCC pin can be used to limit the maximum

high voltage which will be passed by the TCA9544A.

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

pins are 5.5 V tolerant.