A 10Mb/s 4ns jitter direct conversion low Modulation Index FSK demodulator for low-energy body sensor network

A high speed and low jitter direct conversion FSK demodulator for low energy body sensor network (BSN) is implemented in 0.18um CMOS technology with 1V supply. Modulation Index (MI) of 1 is used for high data rate, which performs high duty cycling operation for low-energy BSN. To eliminate deterministic jitter at MI of 1, the demodulator employs a delay locked loop (DLL), demodulation logic and a transition predictive detector (TPD), perceiving the exact data transition point. Dual offset-compensated comparators are utilized to reduce the random jitter during transition predictive operation. As a result, the proposed demodulator achieves absolute jitter of 4ns at a 40Mb/s data rate with a 5MHz base band signal.