A 0.007 mm2 0.6 V 6 MS/s Low-Power Double Rail-to-Rail SAR ADC in 65-nm CMOS

Abstract

A 0.007mm2 0.6V 6MS/s 10b double rail-to-rail input range SAR ADC is implemented in 65-nm technology. The extended input range broadens the applications of the low-power SAR ADCs such as compute-in-memory. The proposed ADC occupies less area since it only needs additional two series-connected capacitors and a differential-difference comparator for double rail-to-rail operation. The set-and-down operation reduces the input-referred noise of the comparator by over ten times than complementary switching. The novel metal-insulator-metal and metal-oxide-metal capacitor hybrid cap-DAC architecture minimize the gain error of ADC. The prototype achieves SNR of 53.90-dB, SNDR of 52.12-dB, and SFDR of 60.39-dB, power of 12.98- $\\mu \\text{W}$ , and FoM of 6.6-fJ/conv.-step.