PCA9555DB

I/o Expanders Overview

The PCA9555DB is a remote 16-bit I2C and SMBus I/O expander manufactured by Texas Instruments. It provides general-purpose parallel input/output expansion for I2C/SMBus applications in a 24-pin SSOP package. The device operates with a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. It features an interrupt output pin that activates when any input state differs from its corresponding input port register state. The component includes configuration registers, input/output registers, and polarity inversion registers, allowing individual I/O configuration as inputs or outputs.

I/o Expanders Feature Summary

• Provides 16 bits of general-purpose parallel input/output expansion compatible with I2C and SMBus protocols.
• Features an open-drain interrupt output activated when input states differ from the input port register values.
• Includes configuration registers for selecting input or output modes and polarity inversion registers for active-high or active-low operation.

I/o Expanders Applications

• ACPI power switch control
• Sensor interface expansion
• Pushbutton and LED matrix scanning

I/o Expanders Procurement Notes

Verify the specific suffix 'DB' indicates the SSOP-24 package variant. Confirm RoHS compliance status through official manufacturer documentation. Ensure the operating temperature range meets system requirements. Check for obsolescence notices or lifecycle status updates before finalizing procurement plans.

I/o Expanders Selection Notes

Select this component when 16 additional digital I/O lines are required via I2C or SMBus interfaces. Ensure the system voltage aligns with the 2.3 V to 5.5 V operating range. Consider the interrupt functionality if real-time input change detection is necessary. Verify package availability matches the PCB footprint constraints.

I/o Expanders Part Context

The PCA9555 belongs to the PCA9555 series of I/O expanders designed to enhance Philips family devices. It offers higher drive capability and lower supply current compared to predecessors. The device is software-compatible with PCF8575 but requires adjustments due to enhanced features like configuration registers.

I/o Expanders Replacement Considerations

TCA9555 variants offer extended low-voltage support down to 1.65 V. PCA9535 provides similar functionality with potentially different power characteristics. Verify pinout and register compatibility before substituting with other 16-bit I/O expanders.