Patent ID: 9385601
Filing Date: 2016-07-05
CPC Classification: H02M

Claim Text:
1. A switching mode power supply (SMPS) for converting an input voltage at an input terminal into an output voltage at an output terminal, the SMPS comprising: a switch having a control end; an inductor coupled to the switch; a zero current detection circuit coupled to the inductor, the zero current detection circuit configured to detect an inductor current flowing through the inductor and provide a zero current detection signal, wherein the zero current detection signal is in an effective state only when the inductor current is at zero; a load judgment circuit coupled to the zero current detection circuit, the load judgment circuit configured to provide a plurality of status signals based on a zero current duration during when the zero current detection signal is in the effective state uninterruptedly; and a control signal generating circuit coupled to the output terminal and the load judgment circuit, the control signal generating circuit configured to provide a control signal which is coupled to the control end of the switch, wherein the control signal transits from a first state to a second state when a feedback signal indicative of an output signal at the output terminal satisfies a preset condition with a reference signal, and the control signal transits from the second state to the first state after an on time of the switch, and wherein the on time is controlled based on the plurality of status signals.