A 0.6V 1.63fJ/c.-s. Detective Open-Loop Dynamic System Buffer for SAR ADC in Zero-Capacitor TDDI System

A low-power detective open-loop dynamic (DeOLD) system buffer co-designed with a SAR ADC without using any off-chip decoupling capacitor is proposed. It is pertinent for the zero-capacitor touch with display driver integration (TDDI) system. The system buffer detects the ADC input signal actively to compensate its loss charge back quickly. The dynamic charge sharing technique instead of the well-known pump squeezing technique is adopted to reduce 42.4% power of charger compensators in the buffer. Without the off-chip decoupling capacitor, the DeOLD system buffer co-designed with the 400kS/s 10b SAR ADC consumes 334nW under a 0.6V supply. Its active area is only 0.0098mm2. It achieves an SNDR of 5S.96dB, which results in an FoMw of 1.63fJ/c.-s.

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