Monolithic dc offset self-calibration method for adaptive on-time control buck converter

In this paper, a monolithic self-calibration method is proposed to reduce DC offset of output voltage in buck converter with adaptive on-time control. The calibration system senses the average output voltage of converter and dynamically reduces offset by digital tuning the comparing reference. DC offset at output voltage caused by parasitic ESR, ESL of filter capacitor and loop delay can be effectively calibrated. The proposed calibration method doesn´t impact fast transient response of the converter. Moreover, the calibration system can also be generally used to reduce output voltage DC offset of converter with bang-bang control.