Gated ring oscillator for a time-to-digital converter with shaped quantization noise

A method for determining a measurement time, the measurement time having a plurality of enable periods to be included in the determination and at least one disable period to be excluded from the determination, the method comprising:

• enabling propagation of a transitioning signal through a plurality of delay stages at a first enable time, the delay stages being interconnected to allow sustained transitions to propagate through the delay stages during the enable time and preservation of a state of the delay stages during a disable time allowing the phase of a gated ring oscillator to be preserved and phase integration to resume when an enable signal is asserted having a pulse with a duration substantially equal to a time period to be measured, each delay stage having multiple weighted delay elements and connection to said multiple delay elements are made to the outputs of said delay stages using a connection matrix in such a manner that reduces the delay for each delay stage;
• disabling the propagation of the transitioning signal through the delay stages at a disable time;
• storing the state of the delay stages at the disable time;
• and
• enabling the propagation of the transitioning signal through the delay stages at a second enable time, wherein the propagation resumes at the state of the delay stages stored at the disable time allowing another measurement time to start using the stored state of the delay stages from a previous measurement time and wherein the state represents a voltage on a capacitance of said delay stage.