The RT9730 is an integrated circuit (IC) designed to replace passive device in charging system with extra protection function. It is optimized to protect low voltage system from up to 28V high voltage input. The IC monitors the input voltage to make sure all parameters are operating in normal range. It also monitors its own temperature and turns off the MOSFET when the chip temperature exceeds 140°C. When the input voltage exceeds the threshold, the IC turns off the power MOSFET within 1μs to remove the power before any damage occurs. User can monitor the adapter input voltage from the CHRIN pin, which has 50mA current capability. The gate of the P-MOSFET will be controlled by the external charging controller from GATDRV pin if all parameters are operating in normal range.
The RT9730 is available in a WDFN-8L 2x2 tiny package to achieve best solution for PCB space and total BOM cost saving considerations.