Fast gain-dependent mix dc offset calibration circuit, method, and zero-if receiver

A gain-dependent DC offset calibration method, applied to a zero-IF receiver, wherein the zero-IF receiver comprising a gain controller and a state controller, and the gain-dependent DC offset calibration method comprises:

• outputting, via a DC offset calibration controller, a first control signal enable_mix based on state information rx_state sent by the state controller of the zero-IF receiver, to start a mix DC offset calibrator;
• determining that the first control signal enable_mix is at a first value, and executing, by a mix DC offset calibrator, a mix DC offset calibration algorithm upon determining that the first control signal enable_mix is at the first value to perform mix DC offset calibration to obtain a calibration codeword;
• and
• determining that the first control signal enable_mix is at a second value, and executing, by a digital-domain DC offset calibrator, a digital-domain DC offset calibration algorithm upon determining that the first control signal enable_mix is at the second value to perform digital-domain DC calibration according to the calibration codeword.

A zero-IF receiver, comprising:

• a mixer, a low-pass filter, an ADC, a digital filter, a gain controller, and a state controller, wherein the zero-IF receiver further comprises a gain-dependent DC offset calibration circuit applied to the zero-IF receiver, and the gain-dependent DC offset calibration circuit comprises:
• a DC offset calibration controller, a mix DC offset calibrator, and a digital-domain DC offset calibrator, wherein:
• the DC offset calibration controller is configured to output a first control signal enable_mix based on state information rx_state sent by a state controller of the zero-IF receiver, to start the mix DC offset calibrator;
• the mix DC offset calibrator is configured to execute a mix DC offset calibration algorithm to perform mix DC offset calibration when the first control signal enable_mix is at a first value, to obtain a calibration codeword;
• and
• the digital-domain DC offset calibrator is configured to execute a digital-domain DC offset calibration algorithm when the first control signal enable_mix is at a second value, and perform digital-domain DC calibration according to the calibration codeword.