80mΩ, 500mA High-Side Power Switches with Flag

The RT9721A/B are low voltage, single N-MOSFET high-side power switches, optimized for self-powered and bus- powered Universal Serial Bus (USB) applications. The RT9721A/B series provides a charge pump circuitry to drive the internal MOSFET switch; the switch's low R_DS(ON), 80mΩ, meets USB voltage drop requirements; and a flag output is available to indicate fault conditions to the local USB controller. Additional features include soft-start to limit inrush current during plug-in, thermal shutdown to prevent catastrophic switch failure from high-current loads, under-voltage lockout (UVLO) to ensure that the device remains off unless there is a valid input voltage present. The maximum current is limited to typically 750mA in dual ports in accordance with the USB power requirements, lower quiescent current as 50μA making this device ideal for portable battery-operated equipment.

The RT9721A is designed without output auto-discharge function and RT9721B is designed with output auto-discharge function.

The RT9721A/B are available in SOT-23-5 package requiring minimum board space and smallest components.