A 36-mW 1.5-GS/s 7-Bit Time-Interleaved SAR ADC Using Source Follower Based Track-and-Hold Circuit in 65-nm CMOS
This paper presents a 7-bit 1.5-GS/s time-interleaved (TI) SAR ADC. The scheme achieves better isolation between sub-ADCs thanks to embedding a track-and-hold (T/H) amplifier and reference voltage buffer in each sub-ADC. The proposed dynamic T/H circuit enables high-speed, low-power operation. The prototype is fabricated in a 65-nm CMOS technology. The total active area is 0.14 mm(2) and the ADC consumes 36 mW from a 1.2-V supply. The measured results show the peak spurious-free dynamic range (SFDR) and signal-to-noise-and-distortion ratio (SNDR) are 52.4 dB and 39.6 dB, respectively, and an figure of Merit (FoM) of 300 fJ/conv. is achieved.
time-interleaved sar adc dynamic t/h circuit low-power high-speed