An 88dB 48KHz full feed-forward sigma-delta modulator

摘要

This paper examines the design of full feed-forward sigma-delta modulator which is much more suitable for the CMOS digital process with low supply voltage than the traditional second-order feedback loop. The full feed-forward system reduces the modulator's sensitivity of the circuit non-idealities and decreases the internal signal swing to half the full scale. An implementation in a 0.35um CMOS technology achieved dynamic range of 88dB, bandwidth of 48KHz and power consumption of 5mW. It can operate from supply voltages ranging from 2.4v-3.3v. The architecture is quite useful for low voltage SOC applications, such as portable biomedical system.