LAUSR

In this paper a 0.6 V, 14 bit/500 Hz subthreshold inverter-based sigma–delta modulator is proposed. In the first integrator of the modulator, a bootstrap switch is used to accomplish accurate signal sampling. Without a transconductor operational amplifier (OTA), the sigma–delta modulator adopts a cascode inverter in the subthreshold region to save power consumption. The modulator is fabricated with a 0.13 μm CMOS mixed-signal process. The experiment results show that with the 0.6 V power supply it achieves a maximum SNDR of 69.7 dB and an ENOB of 11.3 bit, respectively, but only consumes 5.07 μw power dissipation.