LED Driver Circuit of Control Closed Loop Analysis
The article introduces a practical circuit for drive LED using half-bridge switch control with current feedback.A half-bridge driver is used as the main circuit and a transformer is used as an isolation cir-cuit.The resistor is used as the current detection sensor of the LED load,with amplifier and opt coupler isola-tion as a negative feedback loop.The transfer function set of all sub circuits is derived and synthesized into ex-pressions for amplitude frequency characteristics and phase frequency characteristics.MathCAD is used to draw Bode plots of amplitude-frequency characteristics and phase-frequency characteristics.By adjusting the parame-ters of circuit components,the Bode plot stability margin determination method is finally satisfaction.
half-bridge controlclosed feedback loopamplitude frequency and Phase frequencyMath-CADbode plotstability margin
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