PCAL9535APW,118

I/o Expanders Overview

The PCAL9535APW,118 is a low-voltage 16-bit General Purpose Input/Output (GPIO) expander with interrupt and reset capabilities for I2C-bus/SMBus applications. It operates within a supply voltage range of 1.65 V to 5.5 V and supports Fast-mode communication up to 400 kHz. The device features Agile I/O enhancements including programmable output drive strength, latchable inputs, and configurable pull-up/pull-down resistors. Packaged in a TSSOP24 format, it provides 16 I/O pins with an open-drain active LOW interrupt output. Standby current consumption is typically 1.5 µA at 5 V and 1.0 µA at 3.3 V.

I/o Expanders Feature Summary

• Agile I/O functionality enabling programmable output drive strength, input latching, and internal pull-up/pull-down resistor configuration.
• Open-drain active LOW interrupt output that signals system masters when input states change without requiring continuous bus polling.
• Hardware address selection via three pins allowing up to eight devices to share the same I2C-bus or SMBus.
• Power-on reset mechanism ensuring all registers initialize to default values and interrupts remain masked during startup.

I/o Expanders Applications

• ACPI power switches
• Sensor interface expansion
• Push-button matrix scanning
• LED control circuits
• Fan speed control systems

I/o Expanders Procurement Notes

Verify the ordering suffix ,118 corresponds to the TSSOP24 package variant. Confirm the temperature range specification matches the application requirements. Ensure the I2C bus pull-up resistors are correctly sized for the operating voltage. Check compatibility with the host microcontroller's interrupt handling logic.

I/o Expanders Selection Notes

Select this component when software backward compatibility with PCA9535 is required alongside enhanced I/O features. Consider the wide voltage range for interfacing with modern low-power processors. Evaluate the need for specific Agile I/O features like input latching or variable drive strength before choosing over standard expanders.

I/o Expanders Part Context

This part belongs to the PCAL9535A series, which serves as a pin-to-pin replacement for the PCA9535 and PCA9535A families. It retains the core register set while adding advanced configuration options. The APW suffix specifically denotes the Thin Shrink Small Outline Package variant suitable for surface mount assembly.

I/o Expanders Replacement Considerations

PCAL9535AHF is the HWQFN24 package equivalent. PCA9535 and PCA9535A are functionally compatible predecessors lacking Agile I/O features. Verify register initialization states and interrupt masking defaults when substituting these variants.