Remotely powered PPM demodulator by inductive coupling for rodent applications
A low-power pulse position modulation (PPM) demodulator has been developed for remotely powered batteryless implantable devices. The required power for the implantable device is provided by the magnetic coupling with the external array of powering of coils placed under the living space of the animal. The remote powering is turned off 6 % of one bit duration during data transmission. The remote powering link is optimized to deliver power at 13.56 MHz frequency. The power is transferred from 30 mm distance with 21 % efficiency. An integrated full-wave rectifier and voltage regulator generate 1.8 V supply voltage from induced signal. The integrated PPM demodulator consumes only 27.8 lW and has 8.33 kb/s data rate. The presented entire system and basic blocks are integrated using a 0.18 mu m CMOS technology. Experimental results verify the effectiveness of the PPM demodulator and the downlink communication system.