| 摘要 |
A pulse width modulation circuit comprising an input circuit (1) inputting a voltage (Vin) through an input end, a voltage difference calculating circuit (2), and a simulation light modulation circuit (3), wherein the voltage difference calculating circuit (2) comprises a resistor (21) and a subtracter (22), one end of the resistor (21) is connected to an output end of the input circuit (1), the other end is taken as an output end of the pulse width modulation circuit, two input ends of the subtracter (22) are respectively connected to two ends of the resistor (21) for calculating a voltage difference between the two ends of the resistor (21), an input end of the simulation light modulation circuit (3) is connected to an output end of the subtracter (22), an output end of the simulation light modulation circuit (3) is connected to a control end of the input circuit (1) for receiving the voltage difference output by the voltage difference calculating circuit (2), and the voltage difference is converted into a pulse width modulation signal which is output to the input circuit (1) for current feedback. According to the pulse width modulation circuit, current feedback can be realized to make the circuit operate in a continuous current mode, ensuring circuit voltage stability. |
