AN ISOLATED DRIVING CIRCUIT

摘要

An isolated driving circuit applied to the power switch of a switching power supply comprises: a control circuit for generating driving pulse signal, an isolated driving transformer (T1) having one primary windings and one or more secondary windings, a block capacitor (C1) connecting the control circuit and the primary windings of the isolated driving transformer (T1), a driving circuit connected between the secondary windings of the isolated driving transformer (T1) and the power switch for driving the power switch, a discharge circuit and turning off circuit ensuring the switch off the power switch. The isolated driving circuit is capable of turning off the power switch reliably, and can control the power loss of the control circuit generating driving pulse signal.