A 101.6-dB-SNDR Fully Dynamic Zoom ADC Using Miller-Compensated Floating Inverter Amplifiers

This brief presents a fully dynamic zoom analog-to-digital converter (ADC) using a Miller-compensated two-stage floating inverter amplifier (MCFIA). Due to the two-stage design, the proposed MCFIA achieves a sufficient gain for a high-resolution delta-sigma modulator design. Compared to the conventional two-stage design, the stability criterion of MCFIA is advantageous in driving bigger sampling capacitors needed to reduce kT/C noise. Moreover, a zoom ADC architecture mitigates the swing range requirement of the MCFIA. A prototype ADC was implemented in a 180-nm CMOS process and achieved a signal-to-noise and distortion ratio (SNDR) of 101.6 dB with an SNDR-based Schreier figure-of-merit of 174.8 dB at a sampling frequency of 2.56 MHz.