PCAL9554CBS,128

I/o Expanders Overview

The PCAL9554CBS,128 is a low-voltage 8-bit General Purpose Input/Output (GPIO) expander designed for I2C-bus and SMBus applications. It features an operating power supply voltage range of 1.65 V to 5.5 V and supports Fast-mode communication at up to 400 kHz. The device includes an open-drain active LOW interrupt output and internal weak pull-up resistors. It utilizes the Agile I/O architecture, offering programmable output drive strength, latchable inputs, and configurable pull-up/pull-down resistors. The component is housed in a 16-HVQFN package with dimensions of 3x3 mm.

I/o Expanders Feature Summary

• Agile I/O capabilities including programmable output drive strength and input latching
• Open-drain interrupt output with maskable functionality and status register
• Configurable internal pull-up and pull-down resistors on all I/O pins
• Power-on reset ensures all channels are configured as inputs upon startup

I/o Expanders Applications

• ACPI power switches
• Sensor interface circuits
• Push button arrays
• LED driving modules
• Fan control systems

I/o Expanders Procurement Notes

Verify the specific ordering suffix '128' against official NXP documentation, as standard datasheets list 'PCAL9554CBS' with packing methods like Reel or HP variants. Confirm that the requested part number corresponds to the HVQFN16 package and matches the required temperature range of -40°C to +85°C before finalizing procurement.

I/o Expanders Selection Notes

Select the PCAL9554CBS variant over the PCAL9554BBS when a distinct fixed I2C address base is required to prevent conflicts with other devices on the bus. Ensure the system design accommodates the 16-HVQFN package requirements, specifically the exposed thermal pad connection to VSS for proper electrical and thermal performance.

I/o Expanders Part Context

This component belongs to the PCAL9554 family, which serves as an enhanced replacement for the PCA9554 and PCA9554A series. The PCAL9554C variant specifically replaces the PCA9554A, distinguished by its unique fixed I2C address bits. This allows for increased device density on a single bus without address collisions compared to the B variant.

I/o Expanders Replacement Considerations

The PCAL9554CBS is a pin-for-pin replacement for the PCA9554A. While software backward compatible with the PCA9554 family, the Agile I/O registers require additional configuration. Verify that existing firmware accounts for the default interrupt masking state at power-up.