Active clamp flyback circuit

A switch-mode power supply, wherein the switch-mode power supply comprises an active clamp flyback converter, wherein the active clamp flyback converter comprises:

• a transformer, wherein the transformer comprises a primary-side winding, a primary-side auxiliary winding, and a secondary-side winding;
• a primary power switching transistor, wherein the primary power switching transistor is connected to the primary-side winding, and the primary power switching transistor is configured to control the transformer to store energy by using the primary power switching transistor;
• and
• an active clamp flyback circuit, wherein the active clamp flyback circuit is connected to the primary-side winding, the primary-side auxiliary winding, and the primary power switching transistor, and the active clamp flyback circuit is configured to absorb leakage inductance energy of the transformer, and
• the active clamp flyback circuit comprises:
• a clamp capacitor, wherein the clamp capacitor is connected to the primary-side winding and is configured to absorb leakage inductance energy of the primary-side winding;
• an auxiliary switching transistor, wherein the auxiliary switching transistor is configured to control the clamp capacitor to perform reverse excitation power charging on the primary-side winding by using the auxiliary switching transistor;
• a first diode, wherein the first diode is connected in series between the clamp capacitor and the auxiliary switching transistor;
• and
• a second diode, wherein the second diode is connected between the first diode and the clamp capacitor, and the second diode is connected in series between the clamp capacitor and the primary-side auxiliary winding, and
• the primary-side winding is connected between the primary power switching transistor and the auxiliary switching transistor, and an electrical connection exists between the primary power switching transistor and the auxiliary switching transistor to form a half-bridge structure.