Texas Instruments

PCA9544APW

PCA9544APW Description

The PCA9544APW from Texas Instruments is an I²C/SMBus translating switch designed for bidirectional voltage-level translation between 2.3V–5.5V systems. Packaged in a 20-pin TSSOP, this obsolete but robust IC facilitates multiplexed communication across multiple I²C buses, making it ideal for complex backplane and PCB designs. It complies with RoHS3 and REACH standards, ensuring environmental safety, and features a Moisture Sensitivity Level (MSL) of 1, suitable for extended storage.

PCA9544APW Features

• Voltage Flexibility: Operates at 2.3V–5.5V, compatible with mixed-voltage systems.
• I²C/SMBus Compliance: Supports standard (100 kHz) and fast-mode (400 kHz) I²C protocols.
• 4-Channel Multiplexing: Enables seamless switching between four downstream I²C buses, reducing GPIO usage.
• Low Standby Current: Optimized for power-sensitive applications.
• Robust ESD Protection: Withstands 2 kV HBM ESD, enhancing reliability in harsh environments.
• Surface-Mount Design: 20-TSSOP package saves board space while ensuring easy integration.

PCA9544APW Applications

• Industrial Automation: Ideal for PLC backplanes requiring multi-bus I²C communication.
• Telecom Equipment: Enables hot-swappable module detection in carrier-grade systems.
• Consumer Electronics: Used in smart displays and multi-sensor hubs for bus isolation.
• Embedded Systems: Simplifies microcontroller-to-peripheral interfacing in mixed-voltage designs.
• Test & Measurement: Facilitates modular instrumentation with isolated I²C channels.

Conclusion of PCA9544APW

The PCA9544APW excels in multi-bus I²C systems by offering voltage translation, channel multiplexing, and robust ESD protection. While obsolete, its low-power operation, compact footprint, and compliance with industry standards make it a reliable choice for legacy or niche applications. Engineers seeking backplane connectivity or mixed-voltage interfacing will find it particularly valuable despite newer alternatives.