TCA9554A

• I²C to Parallel Port Expander
• Open-Drain Active-Low Interrupt Output
• Operating Power-Supply Voltage Range of 1.65 V to 5.5 V
• 5-V Tolerant I/O Ports
• 400-kHz Fast I²C Bus
• Three Hardware Address Pins Allow up to Eight Devices on the I²C/SMBus
• Input and Output Configuration Register
• Polarity Inversion Register
• Internal Power-On Reset
• Low Standby Current Consumption
• 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)
  • 1000-V Charged-Device Model (C101)

The TCA9554A 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. The device can operate with a power supply voltage ranging from 1.65 V to 5.5 V. The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. I/O expanders such as the TCA9554A provide a simple solution when additional I/Os are needed for switches, sensors, push-buttons, LEDs, fans, and other similar devices.

The features of the TCA9554A include an interrupt that is generated on the INT pin whenever an input port changes state. The A0, A1, and A2 hardware selectable address pins allow up to eight TCA9554A devices on the same I²C bus. The device can also be reset to its default sate by cycling the power supply and causing a power-on reset.