PCA9556PW,118

I/o Expanders Overview

The PCA9556PW,118 is an octal SMBus and I2C registered interface manufactured by NXP USA Inc. It provides parallel input/output expansion for SMBus applications within a 16-pin TSSOP package. The device operates with a supply voltage range of 3.0 V to 5.5 V and supports SMBus frequencies up to 100 kHz. It features eight configurable I/O pins that default to inputs upon power-on reset. Key electrical characteristics include a maximum operating current of 1500 μA at 5 V and a standby current of 100 μA. The component includes an active low reset pin, polarity inversion registers, and noise filters on SCL/SDA inputs.

I/o Expanders Feature Summary

• Configurable as input or output via internal configuration register
• Active high polarity inverter register for input signal manipulation
• Internal power-on reset initializes registers and SMBus state machine
• External active low reset pin allows system-level initialization without depowering

I/o Expanders Applications

• SMBus compliant system peripheral expansion
• I2C bus interface logic integration
• Low leakage current power-down scenarios

I/o Expanders Procurement Notes

Verify the specific ordering code PCA9556PW against the required temperature range of -40 to +85 °C. Confirm the package type matches the 16-lead plastic TSSOP (SOT403-1) specification. Ensure compatibility with the fixed 3.3V voltage levels associated with SMBus compliance before finalizing procurement orders.

I/o Expanders Selection Notes

Select this component when designing systems requiring octal I/O expansion specifically for SMBus environments. Note that the PCA9557 serves as a higher-performance pin-for-pin replacement offering I2C support up to 400 kHz. Verify that the 100 kHz SMBus frequency limit meets the system clock requirements.

I/o Expanders Part Context

This part belongs to the Philips Semiconductors integrated circuit family designed for parallel input/output expansion. It functions as a registered interface allowing system masters to control port directions and data states via serial communication protocols.

I/o Expanders Replacement Considerations

The PCA9557 is documented as the higher performance pin-for-pin replacement for the PCA9556.

I/o Expanders FAQ

What is the default state of the I/O pins upon power-up?

All eight I/O pins default to inputs with high impedance output drivers.

How does the external reset function operate?

Asserting a LOW signal on the RESET pin causes the registers and SMBus state machine to return to their default states without requiring the device to be depowered.

What is the maximum SMBus operating frequency?

The maximum SMBus operating frequency is 100 kHz.