CAT9554AYGI

Overview

The CAT9554AYGI is an 8-bit I/O expander manufactured by onsemi, designed for I2C and SMBus communication interfaces. 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 push-pull outputs with configurable sink/source currents ranging from 8 mA to 24 mA. It is housed in a 16-pin TSSOP package suitable for surface mount applications. The component includes power-on reset (POR) functionality and operates across a temperature range of -40°C to +85°C.

Feature Summary

• Supports standard I2C and SMBus serial communication protocols for system integration.
• Provides interrupt output capability to signal state changes to the host processor.
• Includes internal power-on reset circuitry to ensure reliable initialization upon power-up.

Applications

• Portable devices requiring additional GPIO pins within limited board space.
• Industrial control systems utilizing I2C-based sensor networks.
• Consumer electronics needing expanded input/output capabilities via serial buses.

Procurement Notes

Verify the exact suffix configuration against official datasheets, as variations such as AWI or HV4I indicate different packages or electrical characteristics. Confirm availability status through authorized distributors, noting that specific variants may be discontinued or subject to production change notifications. Ensure compliance with RoHS directives and check for alternate supplier qualifications if sourcing from secondary markets.

Selection Notes

Select this component when an 8-bit parallel-to-serial interface is required over I2C or SMBus. Compare pinout compatibility with existing designs, particularly regarding the TSSOP-16 footprint. Evaluate current drive requirements against the 8 mA to 24 mA output specifications. Consider thermal dissipation limits and operating temperature ranges relative to the target application environment.

Part Context

This part belongs to the CAT9554 family of I/O expanders, which also includes variants like CAT9554AWI and CAT9554HV4I. These devices share core functional architectures but differ in packaging options and specific electrical ratings. The family is designed to replace parallel port expanders in modern serial bus systems.

Replacement Considerations

Direct substitutes include NXP PCA9554 series devices, which offer pin-compatible alternatives. Verify register mapping and timing parameters before substitution. Other onsemi variants within the same family may serve as replacements if package differences are accommodated.