PCA9501BS,118

I/o Expanders Overview

The PCA9501BS,118 is an 8-bit I/O expander with integrated 2-kbit EEPROM in a 20-terminal HVQFN package. It operates on a 2.5 V to 3.6 V supply and supports I2C-bus/SMBus interfaces up to 400 kHz. The device features six hardware address pins allowing up to 64 devices on the bus, an active LOW open-drain interrupt output, and 5 V tolerant inputs/outputs. It includes internal power-on reset, noise filters, and hot insertion support.

I/o Expanders Feature Summary

• Integrated 2-kbit EEPROM for board configuration and diagnostic data storage
• Active LOW interrupt output indicating input state changes
• Supports hot insertion for removable backplane systems
• Five-volt tolerant I/Os with internal pull-ups on address lines

I/o Expanders Applications

• Board version tracking and configuration
• Multi-card systems in telecom and networking infrastructure
• Field recall and troubleshooting functions for installed boards

I/o Expanders Procurement Notes

Verify component authenticity through authorized NXP distributors or direct manufacturer channels. Confirm RoHS compliance status and check for recent Product Change Notices (PCN) regarding manufacturing site updates or material substitutions before finalizing procurement orders.

I/o Expanders Selection Notes

Select this model when system design requires 8-bit expansion combined with non-volatile memory storage. Ensure operating voltage remains within the 2.5 V to 3.6 V range. Verify that the HVQFN20 package dimensions fit the available PCB footprint and thermal requirements.

I/o Expanders Part Context

This component belongs to the PCA9501 series of I2C-bus I/O expanders. It serves as a functional replacement for the PCF8574 while adding integrated EEPROM capabilities. The BS suffix specifically denotes the HVQFN20 package variant designed for high-density surface mount applications.

I/o Expanders Replacement Considerations

PCA9501PW,118

I/o Expanders FAQ

How many PCA9501 devices can share a single I2C bus?

Up to 64 devices can be connected to the same I2C-bus/SMBus using the six hardware address pins.

What is the function of the Write Control (WC) pin?

The WC pin must be set to a LOW logic level to enable write operations to the EEPROM; setting it HIGH protects the memory data.

How does the interrupt circuit reset?

The interrupt resets upon reading from or writing to the port that generated the interrupt, or when the port data returns to its original setting.