A low-power PPM demodulator has been developed for remotely powered batteryless implantable devices. The required power is harvested by the magnetic coupling with external powering coils placed under the living space of the animal. The remote powering is turned off only 1% of a bit duration during data transmission. The PPM demodulator consumes only 22.7 mu W at 1.8 V and has 5.55 kb/s data rate. Entire system and basic blocks integrated using a 0.18 mu m CMOS technology are presented. Experimental results show the effectiveness of the PPM demodulator and the communication system.