The TCA6408A is a 16-pin device that provides 8-bits of general purpose parallel input/output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. This device can operate with a power supply voltage ranging from 1.65 V to 5.5 V on both the I2C bus side (VCCI) and on the P-port side (VCCP). This allows the TCA6408A 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.

The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. I/O expanders such as the TCA6408A provide a simple solution when additional I/Os are needed for switches, sensors, push-buttons, LEDs, fans, and so forth.

• I2C to Parallel Port Expander
• Operating Power-Supply Voltage Range of 1.65V to 5.5V
• Allows Bidirectional Voltage-Level Translation and GPIO Expansion Between 1.8-V, 2.5-V, 3.3-V, and 5-V I2C Bus and P-Ports
• Low Standby Current Consumption of 1μA
• 5-V Tolerant I/O Ports
• 400-kHz Fast I2C Bus
• Hardware Address Pin Allows Two TCA6408A Devices on the Same I2C/SMBus Bus
• Active-Low Reset (RESET) Input
• Open-Drain Active-Low Interrupt (INT) Output
• 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
• Schmitt-Trigger Action Allows Slow Input Transition and Better Switching Noise Immunity at the SCL and SDA Inputs
• ESD Protection Exceeds JESD 22
  • 2000-V Human Body Model (A114-A)
  • 1000-V Charged-Device Model (C101)