PCA9675PW,112

I/o Expanders Overview

The PCA9675PW,112 is a remote 16-bit I/O expander for the Fast-mode Plus (Fm+) I2C-bus with an interrupt output. It operates within a supply voltage range of 2.3 V to 5.5 V and features 5.5 V tolerant I/Os. The device provides latched outputs with a sink capability of 25 mA per pin and a total package sink capacity of 400 mA. It supports a 1 MHz I2C-bus interface compliant with Fast and Standard modes, offering an SDA sink capability of 30 mA. The component includes 64 programmable slave addresses via three address pins and operates across a temperature range of -40 °C to +85 °C.

I/o Expanders Feature Summary

• Provides 16-bit quasi-bidirectional I/O expansion with direct LED driving capability through high-current latched outputs.
• Features a 1 MHz Fast-mode Plus I2C-bus interface that allows multiple devices on the bus without requiring external buffers.
• Includes an active LOW open-drain interrupt output to notify microcontrollers of incoming port data without continuous polling.

I/o Expanders Applications

• LED signs and displays
• Servers
• Industrial control systems
• Programmable Logic Controllers (PLCs)
• Cellular telephones

I/o Expanders Procurement Notes

Verify the specific ordering suffix against official NXP documentation to confirm the exact package variant and tape-and-reel specifications. Ensure the procurement channel sources directly from authorized distributors or the manufacturer to guarantee component authenticity and traceability. Cross-reference the part number with the latest datasheet revision to confirm compliance with current RoHS standards and environmental regulations before finalizing purchase orders.

I/o Expanders Selection Notes

Select this component when system design requires expanding I/O capabilities over long distances using the I2C protocol. The high sink current per pin and total package capacity make it suitable for directly driving LEDs without additional transistors. Consider the 64 available addresses if deploying multiple units on a single bus to prevent address conflicts. Verify that the operating voltage range aligns with the target microcontroller's logic levels.

I/o Expanders Part Context

The PCA9675 serves as a drop-in upgrade for the PCF8575, offering significantly higher I2C bus speeds and drive currents. It belongs to the Fm+ family, designed to support more complex peripheral configurations in embedded systems. The TSSOP24 package provides a compact footprint for surface-mount applications, balancing pin count with board space efficiency.

I/o Expanders Replacement Considerations

The PCF8575 is documented as a compatible predecessor, though it lacks the Fm+ speed and higher current drive capabilities. Verify electrical compatibility regarding voltage tolerance and pinout alignment before substitution. Note that the PCF8575 offers fewer programmable addresses and lower bus drive strength compared to the PCA9675.

I/o Expanders FAQ

How are the 64 slave addresses configured?

The addresses are determined by the logic levels applied to the three address pins: AD0, AD1, and AD2. These pins do not have internal pull-up resistors and must be connected to VDD or VSS to select one of the 64 unique addresses.

What is the function of the INT pin?

The INT pin is an active LOW open-drain output that signals the microcontroller when there is incoming data on the I/O ports. It eliminates the need for the master to continuously poll the device for status changes.

Can the PCA9675 reset itself via software?

Yes, the device supports a Software Reset call. The master can send a specific I2C sequence using the General Call address followed by the byte value 06h to reset all registers to their power-up default states.