PCA9538D,118

I/o Expanders Overview

The PCA9538D,118 is an 8-bit I/O expander in a SOIC-16 package. It operates on a supply voltage of 2.3 V to 5.5 V with a maximum clock frequency of 400 kHz. The device provides 8 general-purpose I/O pins that default to inputs at reset. Key features include an active LOW interrupt output and an active LOW reset input. It supports I2C-bus and SMBus protocols, allowing up to four devices to share the same bus via hardware address pins A0 and A1.

I/o Expanders Feature Summary

• Provides 8 bits of General Purpose parallel Input/Output expansion with interrupt and reset capabilities for I2C-bus/SMBus applications.
• Features an open-drain interrupt output activated when any input state differs from its corresponding Input Port register state.
• Includes an active LOW reset input that initializes registers and the device state machine without requiring power cycling.

I/o Expanders Applications

• ACPI power switches
• Sensors
• Push-buttons
• LEDs
• Fans

I/o Expanders Procurement Notes

Verify the specific ordering suffix '118' indicates reel pack SMD packaging with a minimum order quantity of 1000 units. Confirm the operating temperature range is -40 °C to +85 °C. Ensure the SO16 plastic small outline package matches the design requirements. Cross-reference the manufacturer part number PCA9538D with the full ordering code PCA9538D,118 for accurate procurement.

I/o Expanders Selection Notes

Select this component when additional GPIO expansion is required for I2C or SMBus systems. It is suitable for designs needing low standby current and 5 V tolerant I/Os. Consider the removal of internal pull-up resistors compared to similar models like the PCA9554 for reduced power consumption. Verify compatibility with system voltage levels between 2.3 V and 5.5 V.

I/o Expanders Part Context

The PCA9538 enhances the NXP Semiconductors family of I2C-bus I/O expanders. It is identical to the PCA9554 except for the removal of internal I/O pull-up resistors, replacement of the A2 pin with a RESET pin, and a different address range. This modification significantly reduces power consumption when I/Os are held LOW.

I/o Expanders Replacement Considerations

PCA9538BS,118 (HVQFN16 package)

I/o Expanders FAQ

How does the PCA9538 differ from the PCA9554?

The PCA9538 removes the internal I/O pull-up resistor found in the PCA9554, replaces the A2 address pin with a dedicated RESET pin, and utilizes a different I2C address range.

What triggers the interrupt output on the PCA9538?

The open-drain interrupt output is activated when any input state differs from its corresponding Input Port register state. It deactivates when the input returns to its previous state or the Input Port register is read.

Can multiple PCA9538 devices share the same I2C bus?

Yes, up to four devices can share the same I2C-bus/SMBus by varying the fixed I2C-bus address using the two hardware pins A0 and A1.