PCA9555HF,118

I/o Expanders Overview

The PCA9555HF,118 is a 24-pin CMOS device providing 16-bit General Purpose parallel Input/Output (GPIO) expansion for I²C-bus/SMBus applications. 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 an active LOW open-drain interrupt output, polarity inversion registers, and noise filters on SCL/SDA inputs. It includes internal power-on reset and ESD protection exceeding 2000 V HBM. The HWQFN24 package measures 4 × 4 × 0.75 mm.

I/o Expanders Feature Summary

• Provides 16-bit GPIO expansion with individual input/output configuration capabilities
• Features an open-drain interrupt output activated by input state changes
• Includes polarity inversion registers for flexible logic level handling
• Supports multiple devices on the same bus via three hardware address pins

I/o Expanders Applications

• ACPI power switches
• Sensor interfaces
• Push button arrays
• LED control circuits
• Fan management systems

I/o Expanders Procurement Notes

Verify the ordering suffix ,118 corresponds to the HVQFN/HWQFN reel packaging orientation specified in the datasheet. Confirm the manufacturer is NXP Semiconductors. Ensure the component meets RoHS compliance requirements as indicated in official documentation before procurement.

I/o Expanders Selection Notes

Select this variant for designs requiring the HWQFN24 package with a body thickness of 0.75 mm. It serves as an enhanced replacement for PCF8575 but requires software adjustments due to additional configuration registers. Ensure the system controller supports I²C or SMBus protocols for proper communication.

I/o Expanders Part Context

This component belongs to the PCA9555 family of I/O expanders developed by NXP Semiconductors. It enhances previous generations with higher drive capability, 5 V I/O tolerance, and lower supply current. The fixed I²C address is compatible with the PCA9554, allowing mixed device configurations on a single bus.

I/o Expanders Replacement Considerations

PCA9555BS,118

I/o Expanders FAQ

How does the PCA9555 handle input state changes?

The open-drain interrupt output activates when any input state differs from its corresponding input port register state, notifying the system master of the change.

What is the default configuration of the I/O pins at reset?

At power-on reset, all 16 I/O pins are configured as inputs with high-impedance output drivers and weak pull-ups to VDD.

Can the PCA9555 share a bus with PCA9554 devices?

Yes, the fixed I²C-bus address of the PCA9555 is the same as the PCA9554, allowing up to eight devices of either type to share the same bus.