Power, clock, and data recovery in a wireless neural recording device

For many medical applications, neural recording systems should be fully implantable. Transcutaneous wires must be completely eliminated, and this necessitates the wireless transfer of power, clock, and configuration data to the device. We have developed, fabricated, and tested circuits that recover power from a wireless power transmitter and produce a clock from its carrier. A novel data recovery scheme is also presented that allows configuration and command data to be recovered from the amplitude-modulated power waveform. This scheme is robust against glitches and offsets, and requires a minimum modulation depth of 29%. All of these circuits together consume 0.366 mm(2) of area in a 0.5-mu m CMOS process and have a total current draw of 511 mu A.