The present invention discloses a
magnetic isolation drive circuit, comprising a first input end, a second input end, a first output end, a second output end, a switch tube Q10, a
diode D10, a TVS
diode, a
transformer B, a primary winding, a secondary winding, and an acceleration switch-off circuit at the
secondary side, wherein the acceleration switch-off circuit includes at least one switch tubeQ11, the positive
electrode of the TVS
diode is connected to the first input end, the negative
electrode of the TVS diode is connected to the negative
electrode of the diode D10, the positive electrode of the diode D10 is connected to a drain electrode of the switch tube Q10, and a source electrode of the switch tube Q10 is connected to the second input end, and two ends of the primary winding are respectively connected to the first input end and the second input end. In first few cycles of the circuit, when a primary side MOS
transistor is turned off, a primary
voltage of the
transformer isclamped to a set value by the TVS, and the
secondary side can generate a sufficiently large
induced voltage and a
reverse current to drive operation of the acceleration switch-off circuit, to achievea fast switch-off of a driven power switch component, so that the circuit is no longer out of control in the first few cycles.