DTC based carrier shift—online calibration

A method for a digital to time converter (DTC) system, comprising:

• generating a DTC output clock signal at a DTC output frequency, based on a DTC code, at a DTC circuit;
• determining a plurality of period errors respectively associated with a plurality of consecutive edges of the DTC output clock signal, at a period error determination circuit, wherein each period error of the plurality of period errors comprises a difference in a measured time period between two consecutive edges of the DTC output clock signal from a predefined time period;
• determining a correction to be applied to the DTC code based on a subset of the determined period errors, at an integral non-linearity (INL) correction circuit;
• and
• applying the determined correction to the DTC code, at the INL correction circuit.

A transceiver circuit, comprising:

• a transmit path configured to provide a transmit signal at a transmit frequency for subsequent transmission, the transmit path comprising:
• a mixer circuit configured to upconvert an input signal to the transmit signal at the transmit frequency, based on a digital to time converter (DTC) output clock signal;
• and
• a DTC circuit coupled to the mixer circuit and configured to generate the DTC output clock signal at a DTC output frequency, based on a DTC code;
• and
• a calibration circuit, comprising:
• a period error determination circuit configured to determine a plurality of period errors respectively associated with a plurality of consecutive edges of the DTC output clock signal, wherein each period error of the plurality of period errors comprises a difference in a measured time period between two consecutive edges of the DTC output clock signal from a predefined time period;
• and
• an integral non-linearity (INL) correction circuit configured to determine a correction to be applied to the DTC code based on a subset of the determined period errors.