PCA9544AZQNR

Specialized Overview

The PCA9544AZQNR is a 4-channel bidirectional translating I2C multiplexer manufactured by Texas Instruments. It operates within a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies up to 400 kHz. The device features four active-low interrupt inputs and one active-low interrupt output, allowing for efficient bus management. It includes three hardware address pins (A0–A2) enabling up to eight devices on a single I2C bus. The component provides low standby current consumption and ensures glitch-free power-up with all channels deselected.

Specialized Feature Summary

• Supports voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses
• Provides hot insertion support without generating glitches on power-up
• Includes interrupt logic with four dedicated inputs and a combined output

Specialized Applications

• Servers
• Telecom switching equipment routers
• Factory automation systems
• Resolving I2C slave address conflicts in identical sensor arrays

Specialized Procurement Notes

Verify the specific package suffix ZQNR against the manufacturer's orderable addendum to confirm pinout and thermal characteristics. Ensure the design accounts for the required external pull-up resistors on SCL, SDA, and interrupt lines. Confirm that the operating temperature range meets the application requirements.

Specialized Selection Notes

Select this component when multiple I2C slaves share conflicting addresses or require voltage level shifting from a master. It is suitable for designs needing isolated channel selection via software control. Consider the VQFN package dimensions if space constraints are critical compared to TSSOP or SOIC alternatives.

Specialized Part Context

This part belongs to the PCA9544A family of I2C and SMBus multiplexers. It shares functional similarities with the PCA9545A but differs in channel selection logic, as the PCA9544A allows only one channel to be active at a time. It is distinct from repeaters like the PCA9515A which extend bus distance rather than selecting specific downstream paths.

Specialized Replacement Considerations

The PCA9544APWR and PCA9544ARGYR are direct functional equivalents within the same family, differing primarily in package type (TSSOP vs. VQFN). Verify pin compatibility before substitution.