Abstract: A 2-0 cascade gated-ring-oscillator (GRO) based ΔΣ time-to-digital converter (TDC) using time-skew shaping technique is presented in this paper. The proposed TDC includes a ring digital-to-time converter (Ring-DTC) and a time-register (TR) based time-domain adder. By sharing the intrinsic gated-ring quantizer of GRO-TDC, the Ring-DTC has performed no additional matching requirement, calibration free and low power consumption. By dividing the outputs of the GRO quantizer into an MSB segment and an LSB segment, the resolution requirement of Ring-DTC is further released. With the proposed time skew shaping technique, the time-skew of GRO is 1^st order shaped, and the dead-zone effect is solved. At the same time, 2^nd order quantization noise shaping is achieved. This technique is simple to implement and well suited for low-power and wide-band applications.