High voltage pulse width modulation LED driver controller circuit diagram

LED light-emitting diode

1. Start input surge current limiting resistor; 2. For a flow-by-flow passive power factor correction (PPFC) circuit, improve the power factor of the circuit by expanding the conduction angle of the AC input commercial rectifier diode. The factor correction circuit (APFC) has the advantage of low cost; 3. The filter capacitor, when the rectified AC input is close to zero crossing, the energy stored by the storage capacitor C3 is the IC power supply, and the IC is a high voltage power supply IC; 4. Oscillation control . The resistor connected to this pin and ground will set the PWM frequency. The IC can be switched to a constant off time (PFM) mode of operation by connecting the ROSC pin between the external MOSFET gate and the external oscillating resistor; 5. LED string and external MOSFET switch Q1 current sense resistor. If the voltage on the current sense resistor RSENSE exceeds the threshold voltage of the current sense pin CS, the external MOSFET switch Q1 is turned off. The electric energy stored in the inductor will cause the current to continue to supply power to the load LED through the freewheeling diode D1. 6. BUCK conversion power switch tube Q1, AC mains rectified output DC voltage through load, inductance L1, BUCK conversion power switch tube Q1 And the current detecting resistor RSENSE to the ground to form a loop. Once the BUCK conversion power switch Q1 is turned off, the magnetic energy stored in the BUCK inductor forms a gray path through the freewheeling diode D1, and continues to supply power to the load. 7. The BUCK inductor is exchanged when the BUCK conversion power switch Q1 is turned on. The mains rectified output DC voltage forms a loop through the load and the BUCK inductor, and stores energy for the BUCK inductor. Once the BUCK conversion power switch Q1 is turned off, the energy stored in the BUCK inductor needs to be supplied to the load; 8. Output filter capacitor, stable load The supply voltage; 9, freewheeling diode D1, once the BUCK conversion power switch is turned off, the energy stored by the BUCK inductor forms a loop through the load and D1 to continue to supply power to the load.