Wireless power receiver simplifies contactless battery charging

The device combines a wireless power receiver with a constant current/constant voltage battery charger, functioning as the receive circuit component in a complete wireless power transfer system. The unit accepts a rectified 4.2 to 40V input from the receive coil to power a full featured constant current/constant voltage 400mA battery charger that includes programmable charge current, a programmable 3.5 to 11V battery float voltage with ±1% accuracy, battery preconditioning with half hour timeout, bad battery fault detection, NTC thermal protection, charge status and a two hour safety termination timer. In addition, the LTC4120 features dynamic harmonisation control, a patented technique that enables optimal wireless power transfer across a range of conditions while providing thermal management and overvoltage protection. Typical applications include handheld instruments, industrial/military sensors and portable medical devices.