A 12-Bit 200 MS/s Pipelined-SAR ADC Using Back-Ground Calibration for Inter-Stage Gain

Junjie Wu, Jianhui Wu
2020 Electronics  
A 12-bit 200 MS/s pipelined successive-approximation-register (SAR) analogue-to-digital-converter (ADC) implemented in 40 nm CMOS is presented. Such an ADC consists of two asynchronous SAR ADCs and a dynamic amplifier, which consumes a static power of 1.2 mW (the total power is 8 mW) and occupies an area of 0.046 mm2. The inter-stage gain is affected by the parasitic capacitance in SAR ADCs as well as the gain of the dynamic amplifier, which is variable with respect to
more » ... s-voltage-temperature (PVT). A background calibration of the inter-stage gain is proposed to adjust the inter-stage gain and to track the PVT variables. The measurement results show that, with calibration, the spurious-free-dynamic-range (SFDR) and signal-to-noise-and-distortion-ratio (SINAD) can be improved from 68 dB and 61 dB to 78 dB and 63 dB, respectively. The dynamic performance was stable under different VT conditions.
doi:10.3390/electronics9030507 fatcat:kecjg747vbed5kf3eq7rdp2xmu