A 240-mW 2.1-GS/s 52-dB SNDR Pipeline ADC Using MDAC Equalization

This paper introduces multiplying digital-to-analog converter (MDAC) equalization, a digital correction technique for pipeline ADCs that corrects MDAC gain, settling, and other dynamic errors using successive digital FIR filters operating on sub-ADC output samples. This technique reduces the required MDAC residue amplifier (RA) bandwidth relative to the sampling frequency, thereby reducing ADC power. MDAC equalization is demonstrated in a 240-mW 2.1-GS/s ping-pong pipeline ADC in 40-nm CMOS where MDAC RA power is reduced from 175 to 53 mW by 70%. The ADC achieves 58 dB SNR and 52 dB SNDR.