PCA9554APW

I/o Expanders Overview

The PCA9554APW is an 8-bit I/O expander for the I2C and SMBus interfaces, manufactured by Texas Instruments. It operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. The device features three hardware address pins (A0, A1, A2) allowing up to eight devices on a single bus. It includes configuration registers, polarity inversion capabilities, and an open-drain active-low interrupt output. The component is housed in a 16-pin TSSOP package and functions across a temperature range of -40°C to +85°C.

I/o Expanders Feature Summary

• Provides remote I/O expansion via standard I2C/SMBus communication protocols
• Features an open-drain interrupt output that signals state changes without continuous polling
• Includes internal power-on reset logic to initialize registers and the I2C state machine upon startup

I/o Expanders Applications

• Microcontroller peripheral expansion for general-purpose digital inputs and outputs
• System interface modules requiring additional control lines over serial buses
• Embedded systems needing low-power I/O management with interrupt-driven notifications

I/o Expanders Procurement Notes

Verify the specific ordering suffix 'PW' corresponds to the TSSOP-16 package variant required for your design. Confirm the manufacturer is Texas Instruments, as other vendors may produce functionally similar parts with different electrical characteristics or pinouts. Ensure the datasheet revision matches your application requirements regarding timing parameters.

I/o Expanders Selection Notes

Select this component when an 8-bit parallel port expansion is needed over an I2C bus with interrupt capability. Compare against the PCA9554 if a different fixed I2C address is required, as they are identical except for addressing. Consider the TCA9554 if operation below 2.3 V is necessary, as it supports lower voltage ranges.

I/o Expanders Part Context

This part belongs to the PCA9554A family of I/O expanders from Texas Instruments. It is designed to be pin-to-pin compatible with the PCF8574A but requires software adjustments due to enhanced register functionality. The 'A' designation distinguishes its fixed I2C address from the standard PCA9554, allowing mixed usage on the same bus.

I/o Expanders Replacement Considerations

The PCA9554 serves as a direct functional substitute with a different fixed I2C address. The TCA9554 offers expanded voltage compatibility down to 1.65 V. Verify that any replacement maintains the 16-pin TSSOP footprint and interrupt signal logic levels.