1 Features

. Operating power-supply voltage range of 1.65 V to

5.5 V

. Allows bidirectional voltage-level translation and

GPIO expansion between:

. 1.8-V SCL/SDA and

1.8-V, 2.5-V, 3.3-V, or 5-V P Port

. 2.5-V SCL/SDA and

1.8-V, 2.5-V, 3.3-V, or 5-V P Port

. 3.3-V SCL/SDA and

1.8-V, 2.5-V, 3.3-V, or 5-V P Port

. 5-V SCL/SDA and

1.8-V, 2.5-V, 3.3-V, or 5-V P Port

. I2C to Parallel port expander

. Low standby current consumption of 1 μA

. Schmitt-Trigger action allows slow input transition

and better switching noise immunity at the SCL

and SDA inputs

. Vhys = 0.18 V Typ at 1.8 V

. Vhys = 0.25 V Typ at 2.5 V

. Vhys = 0.33 V Typ at 3.3 V

. Vhys = 0.5 V Typ at 5 V

. 5-V Tolerant I/O ports

. Active-low reset input ( RESET)

. Open-drain active-low interrupt output ( INT)

. 400-kHz Fast I2C Bus

. Input/output configuration register

. Polarity inversion register

. Internal power-on reset

. Power up with all channels configured as inputs

. No glitch on power up

. Noise filter on SCL/SDA inputs

. Latched outputs with high-current drive maximum

capability for directly driving LEDs

. Latch-up performance exceeds 100 mA per JESD

78, class II

. ESD protection exceeds JESD 22

. 2000-V Human-body model (A114-A)

. 200-V Machine model (A115-A)

. 1000-V Charged-device model (C101)

2 Description

This 24-bit I/O expander for the two-line bidirectional

bus (I2C) is designed to provide general-purpose

remote I/O expansion for most microcontroller families

via the I2C interface [serial clock (SCL) and serial data

(SDA)].

The major benefit of this device is its wide VCC range.

It can operate from 1.65 V to 5.5 V on the P-port side

and on the SDA/SCL side. This allows the TCA6424A

to interface with next-generation microprocessors

and microcontrollers on the SDA/SCL side, where

supply levels are dropping down to conserve power.

In contrast to the dropping power supplies of

microprocessors and microcontrollers, some PCB

components, such as LEDs, remain at a 5-V power

supply.