CAT9554AWGI-T2

Overview

The CAT9554AWGI-T2 is an 8-bit I/O expander manufactured by onsemi, designed for I2C and SMBus applications. It features a push-pull output configuration with interrupt capability and power-on reset (POR). The device operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. It is housed in a 16-lead TSSOP package with a width of 4.40 mm. The component functions as a general-purpose input/output port, allowing expansion of microprocessor or microcontroller systems while minimizing interconnections.

Feature Summary

• Provides eight bidirectional general-purpose I/O lines accessible via standard I2C/SMBus protocols.
• Includes an interrupt output pin that signals state changes on inputs or completion of write operations.
• Integrates a power-on reset circuit to ensure outputs are in a known inactive state upon initialization.

Applications

• ACPI power switch control interfaces
• Sensor and push-button input expansion
• LED indicator and fan control management

Procurement Notes

Verify the specific suffix 'W' against official datasheets, as it may denote wide temperature range or specific packaging variations. Confirm RoHS compliance status and check for end-of-life notifications, as similar variants in this series have been discontinued. Ensure the ordering part number matches the exact package and temperature grade required for the design.

Selection Notes

Select this component when additional GPIOs are needed for low-voltage systems operating between 2.3 V and 5.5 V. It is suitable for designs requiring minimal board space due to the compact TSSOP-16 package. Consider the 400 kHz bus speed limit and 8 mA to 24 mA output drive capabilities when interfacing with load devices.

Part Context

This part belongs to the CAT9554 family of I/O expanders, originally developed by Catalyst Semiconductor before its acquisition by onsemi. The family provides a solution for expanding I/O ports in embedded systems using serial communication buses. Variants like the CAT9554AYI-G share similar core functionalities but may differ in package type or temperature rating.

Replacement Considerations

The NXP PCA9554B and PCA9554C are functionally compatible alternatives within the same category. These devices offer similar 8-bit I/O expansion over I2C/SMBus with interrupt support. Verify register compatibility and address configurations when substituting.