1V 14uW Switched-Opamp ΔΣ-ADC for Bioelectric Data Aquisition

In this paper, a 1V ΔΣ-ADC for bioelectric data acquisition is presented. Low power consumption is the major requirement in this design. Both the biquad low pass filter and the delta-sigma modulator are designed using switched-capacitors & switched-opamps. The low pass filter is used to limit the signal bandwidth to 100Hz. The modulator is a 3 rd order 1-bit topology. The sampling frequency and OSR are 32 kHz and 64 respectively. The digital filter is multi-stage & multi-rate to reduce power consumption. These circuits are a sub-part of a system-on-chip (SoC) for wireless body area sensor networks called the Sensium ™ . The total area of the circuits is ~0.38mm 2 . The ADC achieves 58dB dynamic range (ENOB~9.6 bits) and consumes 14uW of power.