A Calibration Technique for DVMC with Delay Time Controllable Inverter

: This paper presents a novel calibration method for Delay Value Measurement Circuit (DVMC), a class of embedded time to digital converter (TDC), using a variable clock generator for accurate delay measurement. The proposed method uses a design for calibration as well as a variable clock generator. The design utilizes a delay time controllable (DTC) inverter. It also uses two OR-NAND gates which work as selectors; we reconfigure the construction of the ring oscillator (RO) in DVMC when calibrating the DTC inverter. The proposed scheme accomplishes more accurate calibration compared to the traditional calibration which only uses the variable clock generator. For example, when using a variable clock generator with the resolution of 5.2ps, the resolution of the proposed method is 0.58ps while the traditional method is 5.2ps.