PCA9539DB

I/o Expanders Overview

The PCA9539DB is a 16-bit I/O expander from Texas Instruments designed for I2C and SMBus 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 16 general-purpose I/O pins with an output current capability of 25 mA. It includes configuration registers, an interrupt output pin, and a reset pin for system control. Operating temperatures range from -40°C to +85°C. The component is housed in a 24-pin SSOP package and consumes approximately 100 µA during operation.

I/o Expanders Feature Summary

• Supports I2C and SMBus serial communication protocols for efficient data transfer.
• Includes dedicated interrupt output to notify the host of input state changes without continuous polling.
• Features a hardware reset pin to force internal state machines to default states during power-up or abnormal conditions.

I/o Expanders Applications

• Embedded systems requiring additional digital I/O ports via serial bus.
• Industrial control panels needing remote input monitoring and output driving.
• Consumer electronics utilizing low-power interface expansion.

I/o Expanders Procurement Notes

Verify the specific package variant, as the DB suffix denotes SSOP-24. Confirm end-of-life status with the manufacturer, as this model may be discontinued. Ensure compatibility with existing I2C address configurations and voltage levels before integration into new designs.

I/o Expanders Selection Notes

Select this component when a 16-bit I/O expansion solution is required with I2C connectivity. Consider the SSOP-24 package constraints for PCB layout. Evaluate the need for interrupt-driven versus polled I/O access based on system latency requirements and processor load capabilities.

I/o Expanders Part Context

This part belongs to the PCA9539 series of low-power I/O expanders. It shares functional similarities with other members like the PCA9539PW but differs in packaging. The series is designed to extend microcontroller I/O capabilities over standard serial buses while maintaining low power consumption.

I/o Expanders Replacement Considerations

The TCA9539 is a recommended replacement offering improved power-on reset circuitry and wider voltage support. Verify pin-to-pin compatibility and software register mapping equivalence before substituting the PCA9539DB with newer alternatives.