Patent ID: 8742744

Claim:
A method of sensor-less operation and detection of continuous conduction mode (CCM) and discontinuous conduction mode (DCM) in a switching power converter comprising: determining a duty-cycle (D) of a control switch (S u ) of a switching power convertor; determining a duty-cycle width ratio (D 1 ) of a synchronous rectifier switch (S 1 ) of the switching power convertor; and controlling the switching power convertor such that duty-cycle width ratio (D 1 ) duty-cycle width ratio (D 1 ) is a function of the minimization of duty-cycle (D) such that an optimum duty-cycle width ratio (D 1 ) can be detected for CCM and DCM operation of the switching power convertor which allows detection by a sensor-less CCM-DCM (SLCD) power controller of a zero crossing time instant of a current through an inductor of the switching power convertor without sensing the current through the inductor, wherein controlling the power convertor such that duty-cycle width ratio (D 1 ) is a function of the minimization of duty-cycle (D) such that an optimum duty-cycle width ratio (D 1 ) can be detected for CCM and DCM operation of the switching power convertor comprises controlling the switching power convertor such that D 1 =D/D CCM ·(1−D CCM )=D/V o −V in ·(1−V o /V in ), where D CCM is a value of duty-cycle (D) in CCM, V o is an output voltage value of the power convertor, and V in is an input voltage of the power convertor.