PCA9545AD,112

Specialized Overview

The PCA9545AD,112 is a quad bidirectional translating switch controlled via the I2C-bus. It fans out one upstream SCL/SDA pair to four downstream pairs (channels). The device supports voltage level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses using the VDD pin to limit passed high voltage. Operating power supply voltage ranges from 2.3 V to 5.5 V. It features four active LOW interrupt inputs and one active LOW interrupt output. An active LOW reset input allows recovery from stuck bus states. The package is SO20 with 20 leads.

Specialized Feature Summary

• Provides four independent bidirectional switches for I2C/SMBus communication
• Enables voltage level translation between different bus voltages without external protection
• Includes interrupt logic with dedicated inputs per channel and a combined output
• Supports hot insertion and low standby current operation

Specialized Applications

• Expanding I2C bus capacity by connecting multiple devices with identical addresses
• Interfacing components operating at different voltage levels (e.g., 5V controllers with 3.3V sensors)
• Isolating faulty downstream I2C buses to prevent system-wide lockups

Specialized Procurement Notes

Verify the specific ordering suffix ',112' corresponds to the tube packing method as defined in the NXP datasheet. Confirm that the component is sourced directly from NXP Semiconductors or authorized distributors to ensure authenticity. Check RoHS compliance status against the latest product data sheet revision before procurement.

Specialized Selection Notes

Select this part when four separate I2C channels are required from a single controller line. Ensure the application requires voltage translation capabilities up to 5.5 V. Verify that the SO20 package fits the PCB layout constraints. Consider the interrupt logic requirements if bus monitoring is necessary for the design.

Specialized Part Context

This component belongs to the PCA9545A family of I2C multiplexers and switches. It is manufactured by NXP Semiconductors. The 'AD' designation indicates the SO20 plastic small outline package variant. The ',112' suffix specifies the standard marking and tube packing configuration for industrial temperature range operation.

Specialized Replacement Considerations

The PCA9545APW (TSSOP20) and PCA9545ABS (HVQFN20) offer the same electrical functionality but in different packages. Cross-package replacement requires PCB footprint modification. Other manufacturers may offer functionally similar I2C switches, but pinouts and control registers should be verified.