Zero current controlled dimming circuit and a method thereof

A zero current controlled dimming circuit, comprising:

• a high side power switch;
• a low side power switch, coupled in series with the high side power switch;
• an inductor, having a first terminal coupled to a connection node of the high side power switch and the low side power switch, and a second terminal coupled to an input voltage or an output voltage;
• an error circuit, configured to provide a compensation signal based on a reference signal and a current sense signal indicative of an output current of the zero current controlled dimming circuit;
• a compensation circuit, configured to provide a compensation off time signal based on the compensation signal and a peak value sample and hold signal indicative of a peak value of an inductor current flowing through the inductor;
• and
• a control signal generating circuit, configured to provide a low side switch control signal to control the low side power switch based on the compensation off time signal, wherein after the inductor current decreases to zero, the low side power switch maintains on for a compensation off time period determined by the compensation off time signal.

A control method of a zero current controlled dimming circuit having a high side power switch, a low side power switch and an inductor, the control method comprising:

• generating a compensation signal based on a current sense signal indicating an output current of the zero current controlled dimming circuit, and a reference signal;
• generating a time period control signal based on the compensation signal and a peak value sample and hold signal indicating a peak value of an inductor current flowing through the inductor of the zero current controlled dimming circuit;
• generating a compensation off time signal based on the time period control signal and a slope reference signal;
• and
• controlling the low side power switch being on for a compensation off time period after the inductor current flowing through the inductor decreases to zero.