PCA9554ADWR

I/o Expanders Overview

The PCA9554ADWR is an 8-bit I/O expander for the two-line bidirectional I2C bus, designed for 2.3-V to 5.5-V VCC operation. It provides general-purpose remote I/O expansion via the I2C interface and features an open-drain active-low interrupt output. The device includes one 8-bit Configuration register, Input Port register, Output Port register, and Polarity Inversion register. At power on, the I/Os are configured as inputs with a weak pullup to VCC. Three hardware address pins (A0, A1, A2) allow up to eight devices to share the same I2C/SMBus. The outputs have high-current drive capability for directly driving LEDs.

I/o Expanders Feature Summary

• Open-Drain Active-Low Interrupt Output
• Operating Power-Supply Voltage Range of 2.3 V to 5.5 V
• 5-V Tolerant I/Os
• 400-kHz Fast I2C Bus

I/o Expanders Applications

• ACPI power switch control
• Sensor interface expansion
• Button input monitoring
• LED direct driving

I/o Expanders Procurement Notes

Verify the specific package type and temperature grade against the datasheet before procurement. Confirm that the ordering suffix matches the required tape-and-reel or cut-tape format. Ensure the voltage range and current drive capabilities align with the target application requirements. Check for any errata regarding interrupt handling in the latest documentation.

I/o Expanders Selection Notes

Select this component when 8-bit I/O expansion is needed over an I2C bus with a 2.3-V to 5.5-V supply. Consider the PCA9554A variant if a different fixed I2C address is required compared to the PCA9554. Ensure the system can accommodate the open-drain interrupt structure and the necessary pull-up resistors. Verify compatibility with the microcontroller's I2C speed and voltage levels.

I/o Expanders Part Context

The PCA9554A is part of Texas Instruments' family of remote 8-bit I2C and SMBus expanders. It is pin-to-pin and I2C address compatible with the PCF8574 series but requires software changes due to enhanced features like higher drive capability and configurable polarity. The 'DW' suffix indicates the SOIC-16 package, while 'R' denotes reel packaging.

I/o Expanders Replacement Considerations

PCA9554DWR is a direct replacement with identical functionality but a different fixed I2C address, allowing up to 16 devices on the same bus when combined with PCA9554 variants.