CY8C9540A-24PVXIT

Overview

The CY8C9540A-24PVXIT is a 40-bit I/O expander with integrated EEPROM, operating within a 3 V to 5.25 V supply range and supporting temperatures from -40 °C to +85 °C. It features an I²C interface compatible with SMBus, allowing up to 128 devices on a single bus via extendable soft addressing. The device provides 40 independently configurable GPIO pins across five ports (GPort 0–4), eight 8-bit PWM sources, and 11 Kbytes of user-available EEPROM. It includes an interrupt output for input changes or PWM state updates, an internal power-on reset, and a configurable watchdog timer.

Feature Summary

• Supports 40 individually configurable general-purpose I/O pins with multiple drive modes including strong drive, open drain, and resistive pull-up/down.
• Integrates eight independent 8-bit PWM outputs clocked by selectable internal sources.
• Includes 11 Kbytes of serial EEPROM for data storage and persistent configuration defaults.
• Features extendable soft addressing algorithm enabling flexible I²C address assignment using available GPIO pins.

Applications

• Monitoring and controlling board-level devices such as LEDs and system intrusion detection sensors.
• Storing error codes or manufacturing data in onboard EEPROM for diagnostic read-back.
• Expanding microcontroller I/O capabilities in systems requiring high pin counts over I²C.

Procurement Notes

Verify the ordering suffix against the manufacturer's current datasheet to confirm package type and temperature grade. Ensure the I²C master supports clock stretching, as required by this device. Confirm that the application design accounts for the specific pinout of the SSOP-48 package and the electrical characteristics defined in the official documentation.

Selection Notes

Select this component when a system requires more than 20 I/O lines but fewer than 60, specifically needing integrated PWM generation and non-volatile storage. Compare against CY8C9520A for lower pin counts or CY8C9560A for higher density. Ensure the I²C bus speed and addressing scheme align with the system architecture requirements.

Part Context

This part belongs to the CY8C95xxA family of multi-port I/O expanders, which also includes the CY8C9520A and CY8C9560A. All devices in the family share identical operational logic but differ in the number of I/O pins, PWM sources, and EEPROM size. The CY8C9540A serves as the mid-range option with 40 bits and 11 Kbytes of EEPROM.

Replacement Considerations

CY8C9540A-24PVXI