A digital-to-time converter (DTC) assisted all digital phase locked loop (ADPLL) circuit is disclosed, which comprises: a DTC error compensator arranged to receive a phase offset signal being a processed output from a time-to-digital converter (TDC) circuit, the phase offset signal includes a DTC error corresponding to a phase difference between a reference clock signal processed by a DTC circuit and a feedback clock signal derived from an output signal of the ADPLL circuit. The compensator is arranged to process the phase offset signal for generating a digital signal representative of the DTC error, which is provided as an output signal. Also, the output signal is arranged to be subtracted from the phase offset signal to obtain a phase rectified signal of the phase offset signal.