PCA9555D,118

I/o Expanders Overview

The PCA9555D,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 from 0 Hz to 400 kHz. The component features an active LOW interrupt output, polarity inversion registers, and noise filters on SCL/SDA inputs. It includes internal power-on reset and defaults to 16 inputs at startup. The device offers ESD protection exceeding 2000 V HBM and latch-up testing per JEDEC JESD78 standards.

I/o Expanders Feature Summary

• Provides 16 bits of 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 up to eight devices sharing the same bus via hardware address pins

I/o Expanders Applications

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

I/o Expanders Procurement Notes

Verify the ordering suffix '118' corresponds to the reel packing method specified in the datasheet. Confirm the SO24 package variant matches the required board layout dimensions. Ensure the operating temperature range of -40°C to +85°C aligns with the target environment specifications before finalizing procurement orders.

I/o Expanders Selection Notes

Select this component when additional I/O ports are required for I2C-based systems. It serves as a pin-to-pin compatible replacement for PCF8575, though software adjustments are necessary due to enhanced features. Consider the 5 V tolerant I/Os if interfacing with mixed-voltage logic levels. Verify that the interrupt functionality meets the system's real-time response requirements.

I/o Expanders Part Context

This part belongs to the PCA9555 series developed by NXP Semiconductors to enhance their family of I2C-bus I/O expanders. It improves upon previous generations with higher drive capability, lower supply current, and smaller packaging options. The fixed I2C-bus address is compatible with the PCA9554, allowing mixed device configurations on the same bus.

I/o Expanders Replacement Considerations

PCF8575 is pin-to-pin and address compatible but requires software changes due to functional enhancements in the PCA9555.