PCA9535CD,118

I/o Expanders Overview

The PCA9535CD,118 is a 24-pin CMOS I/O expander providing 16 bits of General Purpose parallel Input/Output expansion for I2C-bus and SMBus applications. It operates within a supply voltage range of 2.3 V to 5.5 V with a maximum clock frequency of 400 kHz. The device features an active LOW interrupt output, polarity inversion registers, and noise filters on SCL/SDA inputs. It supports up to eight devices sharing the same bus via hardware address pins A0, A1, and A2. The component includes internal power-on reset functionality and ESD protection exceeding 2000 V HBM.

I/o Expanders Feature Summary

• Provides 16-bit GPIO expansion with individual input/output configuration capabilities
• Features an open-drain interrupt output activated by input state changes
• Includes polarity inversion registers to support active HIGH or active LOW operations

I/o Expanders Applications

• ACPI power switch control
• Sensor interface expansion
• Push button scanning
• LED driver control
• Fan speed monitoring

I/o Expanders Procurement Notes

Verify the specific ordering suffix '118' corresponds to the REEL 13" Q1/T1 packing method as documented in the official NXP datasheet. Confirm that the SO24 package variant matches the required board layout dimensions. Ensure the procurement source provides valid traceability documentation for the NXP Semiconductors manufacturer.

I/o Expanders Selection Notes

Select this component when 16-bit I/O expansion is required over standard I2C interfaces. Choose the PCA9535CD variant specifically if open-drain outputs are acceptable or preferred for the application logic levels. Verify compatibility with the system's I2C bus voltage levels and ensure the operating temperature range meets the environmental requirements.

I/o Expanders Part Context

This part belongs to the PCA9535 family of low-power I/O port expanders. It is pin-to-pin and I2C-bus address compatible with the PCF8575, though software modifications are necessary due to architectural enhancements. It differs from the PCA9555 by the removal of internal I/O pull-up resistors, which reduces power consumption when outputs are held LOW.

I/o Expanders Replacement Considerations

The TCA9535 is a register-compatible alternative from Texas Instruments. Software changes may be required due to differences in register mapping and default states compared to the NXP version.