RT9742BNGJ5F

Overview

The RT9742BNGJ5F is a single-channel N-channel power distribution switch and load driver manufactured by Richtek USA Inc. It operates within a load voltage range of 2.7V to 6V and supports a maximum output current of 3A. The device features a typical on-resistance of 55 milliohms and utilizes a non-inverting input type with an open/switch interface. Packaged in a TSOT-23-5 (FC) surface-mount case, it functions as a high-side USB switch without requiring a separate VCC/VDD supply voltage.

Feature Summary

• Integrates fixed current limiting, over-temperature protection, reverse current blocking, and under-voltage lockout for comprehensive fault management.
• Provides a status flag output to indicate operational state or fault conditions.
• Supports load release functionality for controlled power disconnection.

Applications

• USB port power switching and protection
• High-side load distribution in portable electronics
• Battery-powered device power management

Procurement Notes

Verify the specific suffix 'B' against the official Richtek datasheet to confirm exact electrical tolerances and pinout compatibility. Ensure the TSOT-23-5 package dimensions match the target PCB footprint. Confirm RoHS3 compliance requirements align with project specifications before finalizing procurement.

Selection Notes

Select this component when a compact, single-channel high-side switch is required for loads up to 3A within a 2.7V to 6V range. The low 55mOhm on-resistance minimizes power loss. Consider the integrated fault protections if system reliability against overcurrent or thermal events is critical. The non-inverting control simplifies logic interfacing.

Part Context

This part belongs to the RT9742 family of power distribution switches. It shares the base architecture with variants like the RT9742AGJ5F and RT9742ENGJ5F, differing primarily in specific manufacturing batches or minor parameter tolerances defined by the suffix. All variants utilize the same TSOT-23-5 package and core functional block diagram.

Replacement Considerations

The RT9742AGJ5F is a confirmed substitute within the same product family, offering identical 3A capability and 55mOhm resistance in the same package. Verify that the specific 'B' suffix parameters of the original part are acceptable replacements for the 'A' suffix variant.

FAQ

Does the RT9742BNGJ5F require a separate supply voltage?

No, the device does not require a separate VCC or VDD supply voltage; it is powered directly through the load path.

What protection features are included?

It includes fixed current limiting, over-temperature shutdown, reverse current blocking, and under-voltage lockout (UVLO).