RT9742QNGJ5

Overview

The RT9742QNGJ5 is a single N-channel high-side power switch IC designed for USB applications. It operates within a load voltage range of 2.7V to 6V and features an on-resistance of 55mΩ or 70mΩ depending on the specific current rating variant. The device integrates comprehensive protection mechanisms including fixed over-current protection, short circuit fold-back, thermal shutdown, and under-voltage lockout (UVLO). A flag output indicates fault conditions to the host controller. It utilizes a TSOT-23-5 package and supports an operating temperature range of -40°C to 85°C.

Feature Summary

• Integrates an embedded delay function to prevent misoperation caused by inrush current.
• Provides a status flag output to signal fault conditions to the local USB controller.
• Combines low switch-on resistance with low supply current for efficient power management.

Applications

• USB power supply circuits
• Portable electronic devices requiring high-side switching
• Battery-powered systems needing load protection

Procurement Notes

Verify the specific suffix codes against the manufacturer's official datasheet to confirm exact electrical parameters such as on-resistance and maximum continuous current ratings. Ensure the 'Q' designation aligns with required automotive or industrial qualification standards if applicable. Confirm package availability matches the TSOT-23-5 form factor specified in the component documentation.

Selection Notes

Select this component when a cost-effective, low-voltage single-channel high-side switch is required for USB interfaces. Consider the integrated protections like UVLO and thermal shutdown for robust system reliability. Evaluate the on-resistance value relative to the expected load current to ensure efficiency meets design constraints without exceeding thermal limits.

Part Context

The RT9742 series consists of low-voltage, single N-MOSFET high-side power switches optimized for USB applications. Available in multiple packages including TSOT-23-5 and SOT-23-3, these ICs offer flexible integration options. The family emphasizes low on-resistance and low quiescent current while providing essential protection features for portable electronics.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material. Consult the manufacturer's official documentation for direct replacements or pin-compatible alternatives within the same product family.

FAQ

What protection features are integrated into the RT9742?

The device includes over-current protection, short fold-back circuitry, thermal shutdown, and under-voltage lockout (UVLO).

How does the device handle inrush current?

An embedded delay function is integrated to prevent misoperation resulting from inrush current during turn-on.