Abstract: A 1-1 MASH delta-sigma time-to-digital converter using charge-pump based time-amplifier and gain calibration technique is proposed. The TDC using two cascaded gated-ring-oscillator based TDCs and achieved 2nd order noise shaping. By adopting of a high gain charge-pump based time amplifier, the quantization noise of proposed TDC is further diminished. The proposed TDC is designed and simulated on SMIC 40 nm 1P8M CMOS process, achieved high bandwidth, high resolution (low integrated noise) and large dynamic range.