PCA9543AD,112

Specialized Overview

The PCA9543AD,112 is a bidirectional translating switch controlled by the I2C-bus, designed to fan out an upstream SCL/SDA pair to two downstream pairs. It operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies from 0 Hz to 400 kHz. The device features low on-state resistance, ranging from approximately 49 Ω to 65 Ω depending on voltage conditions. It includes two active LOW interrupt inputs and one combined interrupt output. The component is housed in a 14-lead SOIC package (SO14) with an operating temperature range of -40 °C to +85 °C.

Specialized Feature Summary

• Provides hardware-selectable address pins allowing up to four devices on a single I2C bus segment.
• Supports voltage level translation between different bus voltages such as 1.8 V, 2.5 V, 3.3 V, and 5 V without external protection.
• Includes an active LOW reset input to recover from stuck bus states and deselect all channels.

Specialized Applications

• Expanding I2C bus capacity in embedded systems by connecting multiple slave devices.
• Isolating I2C buses with different voltage levels to enable communication between 5 V and lower voltage components.
• Managing interrupt signals from multiple downstream I2C devices through a consolidated interrupt output.

Specialized Procurement Notes

Verify the ordering suffix '112' corresponds to the standard tube packaging format specified in the NXP data sheet. Confirm that the SO14 package dimensions match the required PCB footprint. Ensure the procurement source provides documentation confirming the device meets the specified -40 °C to +85 °C operating temperature range and RoHS compliance standards.

Specialized Selection Notes

Select this component when a 2-channel I2C switch with interrupt logic is required. The PCA9543A variant uses a fixed slave address starting with bits 11100, distinct from the PCA9543B variant. Consider the SO14 package availability if surface mount space allows for a 3.9 mm body width. Verify that the system design accommodates the maximum power dissipation of 400 mW and the thermal resistance characteristics of the SO14 package.

Specialized Part Context

The PCA9543AD,112 belongs to the PCA9543A/43B family of 2-channel I2C-bus switches. The 'AD' designation indicates the SO14 plastic small outline package variant, while 'PCA9543A' specifies the fixed portion of the slave address. This part is functionally identical to the PCA9543BPW except for the address mapping and package type.

Specialized Replacement Considerations

The PCA9543APW serves as a pin-compatible alternative in the TSSOP14 package. The PCA9543B series offers an alternate slave address configuration for resolving address conflicts in larger systems. Texas Instruments equivalents such as the TCA9543A may be considered but require verification of electrical parameter compatibility.