PCA9538D,112

I/o Expanders Overview

The PCA9538D,112 is an 8-bit I/O expander in a 16-pin SO package. It operates on a supply voltage of 2.3 V to 5.5 V and supports I2C/SMBus communication up to 400 kHz. The device provides 8 configurable GPIOs with an open-drain interrupt output and an active-low reset input. It includes registers for configuration, polarity inversion, and data storage. Operating temperatures range from -40 °C to +85 °C.

I/o Expanders Feature Summary

• Provides 8 bits of general-purpose parallel input/output expansion via I2C-bus or SMBus.
• Features an active-low interrupt output that activates when any input state differs from its corresponding Input Port register state.
• Includes an active-low reset input pin that initializes the device state machine without requiring power cycling.
• Supports hardware address selection using two pins (A0 and A1) to allow up to four devices on the same bus.

I/o Expanders Applications

• ACPI power switches
• Sensor interfaces
• Push-button scanning
• LED control circuits

I/o Expanders Procurement Notes

Verify the specific ordering suffix '112' corresponds to tube packaging as indicated in official documentation. Confirm the manufacturer designation matches NXP Semiconductors specifications. Ensure the component meets RoHS requirements and check for any product discontinuance notifications prior to finalizing procurement plans.

I/o Expanders Selection Notes

Select this component when additional digital I/O lines are required for systems utilizing I2C or SMBus protocols. It is suitable for applications needing low standby current and 5 V tolerant inputs. Consider the SO16 package dimensions and thermal characteristics during PCB layout design.

I/o Expanders Part Context

This part belongs to the PCA9538 family of I/O expanders developed by NXP Semiconductors. It is functionally identical to the PCA9554 but lacks internal I/O pull-up resistors to reduce power consumption. The device replaces the A2 address pin with a dedicated RESET pin and utilizes a different I2C address range.

I/o Expanders Replacement Considerations

PCA9554: Functionally similar but includes internal I/O pull-up resistors.

I/o Expanders FAQ

How does the PCA9538 handle power-on reset?

An internal Power-On Reset (POR) holds the device in a reset condition until VDD reaches the VPOR threshold, after which registers initialize to default states.

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

At reset, all eight I/O pins are configured as inputs with high-impedance output drivers.

Can the polarity of the input data be inverted?

Yes, the Polarity Inversion register allows the user to invert the polarity of the Input Port register data for active HIGH or active LOW operation.