Led driver and operating method thereof

An operating method of an LED driver, wherein the LED driver is configured to be electrically coupled to an AC power source for supplying power to a first LED light source, the LED driver comprises a first conversion circuit, a first switch circuit and a control circuit, a positive output terminal and a negative output terminal of the first conversion circuit are electrically coupled to the first LED light source through two switches of the first switch circuit respectively, the control circuit is electrically coupled to the first conversion circuit and the first switch circuit, and the operating method comprises:

• configuring the control circuit to receive a control command and generate a dimming signal to correspondingly configure the first conversion circuit to generate a first output voltage and a first output current for supplying power to the first LED light source;
• and
• after the control circuit receives a light-off command, generating the dimming signal to configure the first conversion circuit to decrease the first output current by the control circuit, and when the control circuit determines that the first output current flowing through the first switch circuit is less than a turn-off current threshold, configuring the two switches of the first switch circuit to be in a non-conduction state by the control circuit.