A high-precision DC measurement read-out integrated circuit (ROIC) is implemented from a low-noise capacitively-coupled chopper instrumentation amplifier (CCIA) followed by a high-resolution incremental discrete-time delta-sigma modulator (DTΔΣΜ) analog-to-digital converter (ADC). In this paper, a doubled sampling-time (DST) incremental DTΔΣΜ is proposed to reduce CCIA’s bandwidth. Through the proposed technique, the power consumption of the traditionally power-hungry IA is halved, while the desired system specifications such as output data rate (ODR) and effective resolution (ER) are maintained. Implemented in a standard 0.13-μm CMOS process, the ROIC’s effective resolution is 21.0 bit at gain 1 and that of 19.8 bit at gain 64. The analog part draws only 114.4 μA from 3-V supply.