Low power DT delta-sigma modulator with ring amplifier SC-integrator

This paper presents a low power DT sigma-delta modulator for wide variety of sensor application using a ring amplifier for SC-integrator. The topology is a second order modulator with single-bit quantizer. Dead-zone effect of the ring amplifier in oversampling ADC is discussed. The fabricated test chip in 65nm CMOS process achieved SNDR of 62dB and 1MHz signal band at sampling frequency of 102.4MHz. The power consumption is 1mW and FoM is 483fJ/conv.step.