A wireless power solution for wearable devices is based on the integrated transmitter power IC NUT1000. It operates at 6.78 MHz with a proprietary controlled magnetic resonance technology and features small receiver and transmitter coils suitable for wearable devices. The transmitter takes 5-V input commonly available from USB ports, and a receiver outputs regulated 5-V power suitable for most battery chargers and small electronic devices. With a 43-mm diameter TX coil and a 32-mm RX coil as thin as 0.25mm it maintains an efficiency of 60% at an output between 1 to 3 W and a peak efficiency of 70% for a 5-V output. For smaller devices, a 15-mm TX winding and a 10-mm RX winding include a magnetic shield and maintain over 50% efficiency over an output power from 1 to 2.5W.
The power management IC integrates all key functional blocks to implement proprietary controlled magnetic resonance architecture in a power transmitter, including power MOSFETs, gate drivers, current sensing, and an I2 C interface. It is provided in a 5 x 5-mm QFN package, and supports an input voltage from 4.5 to 28-V. For more information: , (408) 520 1672, .