This paper introduces a VCO-based non-uniform sampling ADC that leverages phase-domain level crossing and VCO linearity calibration without continuous-time comparators and a reference voltage generator. The SQNR is improved by first-order noise shaping and inherent dithering via non-uniform oversampling, as extra samples are naturally created by the free-running oscillation of VCO. This ADC achieves 200MHz BW with 62dB DR and consumes 19.7mW with an active area of 0.13 mm² in 65nm CMOS.