CAT9555WI-T1

Overview

The CAT9555WI-T1 is a CMOS device providing 16-bit parallel input/output port expansion for I2C and SMBus compatible applications. It consists of two 8-bit configuration ports, input/output registers, polarity inversion registers, and an active low interrupt output. 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 features five address input pins allowing up to eight devices on the same bus. The unit is housed in a 24-lead TSSOP package and operates across an industrial temperature range from -40 °C to +85 °C.

Feature Summary

• Supports I2C and SMBus protocols with individual I/O configuration capabilities
• Features an active low interrupt output indicating input state changes
• Includes internal power-on reset and noise filters on SDA/SCL inputs
• Provides high drive capability with 5 V tolerant I/Os

Applications

• White goods such as dishwashers and washing machines
• Handheld devices including cell phones and digital cameras
• Data communications equipment like routers, hubs, and servers

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation before procurement. The datasheet revision history indicates that certain part numbers, including those with the WI suffix, have been marked as discontinued or removed from the orderable list. Confirm availability status directly with authorized distributors or sales representatives to ensure compliance with current production statuses.

Selection Notes

Select this component when expanding GPIO requirements via standard serial interfaces. Ensure the system master can handle the open-drain interrupt logic and pull-up resistor requirements. Verify that the operating voltage aligns with the 2.3 V to 5.5 V specification. Consider the physical dimensions of the TSSOP-24 package during PCB layout planning.

Part Context

This component belongs to the CAT9555 series of I/O expanders manufactured by onsemi. The series provides general-purpose input/output expansion solutions for embedded systems requiring additional control lines over limited interface buses. The device integrates multiple registers for flexible configuration of port directions and data polarity.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. The datasheet notes that the CAT9555WI variant has been marked as discontinued. Consult official replacement guides or contact the manufacturer for current equivalent components.