A Programmable 34 nW/Channel Sub-Threshold Signal Band Power Extractor on a Body Sensor Node SoC

We present a synthesizable, sub-threshold, four-channel signal band power extractor for a batteryless body sensor node system on chip (SoC). The power extractor consists of a programmable 30-tap finite impulse response (FIR) filter and signal power circuit (SPC). The filter uses a serial, resource-shared architecture to reduce area, leakage, and power. The FIR supports a programmable number of taps, number of active channels, and coefficient register data. The SPC uses power-of-two arithmetic for reduced complexity, area, and power. The design was synthesized in 130-nm CMOS and consumes 34 nW (32 nW for FIR, 2 nW for SPC) per channel at 350 mV and 29 kHz.