5-W wireless power transmitter offers foreign object detection

The LTC4125 , a wireless power transmitter complementing the company’s wireless receiver ICs, is a simple, high performance monolithic full bridge resonant driver, capable of delivering up to 5W of power wirelessly to a companion receiver. It functions as the transmit circuit component in a complete wireless power transfer system comprised of transmit circuitry, transmit coil, receive coil and receive circuitry.

The wireless power transmitter improves upon a basic transmitter by providing: an AutoResonant function that maximizes available receiver power, an optimum power search algorithm that maximizes overall wireless power system efficiency, and foreign object detection (FOD) to ensure safe and reliable operation when working in the presence of conductive foreign objects. This AutoResonant switching enables the device to deliver maximum power from a low voltage input supply (3 to 5.5 V) to a tuned receiver such as the LTC4120 wireless receiver and battery charger, via loosely coupled coils. Applications include handheld instruments, industrial/military sensors and similar devices in harsh environments, portable medical devices, and electrically isolated devices. The device is specified for operation from –40° to 125°C.