DC-DC CONVERTOR HAVING OVER-VOLTAGE/OVER-CURRENT PROTECTION FUNCTION AND LED DRIVING CIRCUIT COMPRISING THE SAME

摘要

A DC-DC converter having an over-current/over-voltage protection function and an LED driving circuit comprising the same are provided to block the operation of the circuit before a circuit breakdown is generated, by detecting an over-current and an over-voltage phenomenon due to open-circuit or short-circuit of a load in advance. In a DC-DC converter for providing a constant voltage to a load by controlling on/off time of a switch(160) by controlling the width of a switching pulse outputted from a PWM control part(150), a micro controller(120) detects a voltage from one end of the load and generates an abnormal signal when a detected voltage is higher than a pre-established voltage. A digital-analog conversion part(130) outputs a voltage of 0V by receiving the abnormal signal. An analog dimming part(140) generates a control signal changing the on-time of the switching pulse outputted from the PWM control part into zero by receiving the 0V voltage from the digital-analog conversion part and then provides the control signal to the PWM control part.