A 2.4ps resolution 2.1mW second-order noise-shaped time-to-digital converter with 3.2ns range in 1MHz bandwidth

A time-to-digital converter (TDC) employs a phase-reference second-order continuous-time delta-sigma modulator to achieve high resolution and low power. The modulator operates on the phase of the input signal and generates an equivalent noise-shaped one-bit output data stream. Fabricated in an LP 90nm CMOS process, the prototype TDC achieves better than 2.4ps resolution over a 3.2ns range in a 1MHz signal bandwidth while consuming 2.1mW from a 1.2V supply.