High-voltage started high frequency flyback PWM (Pulse Width Modulation) control circuit

Abstract

A high-voltage started high frequency flyback PWM (Pulse Width Modulation) control circuit comprises an alternating current power supply pin, a direct current power supply pin and a starting charging branch circuit which is connected with the direct current power supply pin. The high-voltage started high frequency flyback PWM control circuit is characterized by further comprising a direct current power supply pin voltage detecting circuit connected with the direct current power supply pin and the starting charging branch circuit, wherein the direct current power supply pin voltage detecting circuit is used for detecting the voltage of the direct current power supply pin and controlling the opening and closing of the starting charging branch circuit. The high-voltage started high frequency flyback PWM control circuit preferably further comprises a driving circuit and an oscillator which is connected with the driving circuit, wherein the vibrating frequency of the oscillator is not less than 100 KHz. Through the adoption of the high-voltage started high frequency flyback PWM control circuit provided by the invention, the charging branch circuit during starting is controlled and the charging branch circuit is closed after the starting of the system is finished, so that the energy consumption during the working of the system is reduced, and the working efficiency of the control circuit is increased. The system prefers higher frequency, so that the volume and weight of the system are reduced, and greater convenience for system integration is achieved.

Description

technical field [0001] The invention belongs to the field of electronics, and relates to a high-voltage start-up high-frequency flyback PWM control circuit. Background technique [0002] Pulse Width Modulation (PWM) is the abbreviation of "Pulse Width Modulation" in English, referred to as Pulse Width Modulation. The control circuit establishes a feedback loop by sampling the output, and adjusts the switching duty cycle of the power tube to control the output. For example, for power The tube is NMOS, the gate voltage is a square wave pulse signal, and the duty cycle of the gate voltage signal determines the output voltage and output current. [0003] The PWM control circuit is roughly divided into voltage-type and current-type feedback control according to the amount of feedback. The voltage type only samples the output voltage and introduces loop control, while the current type samples both the output voltage and the power tube current to feed back the control loop. The tw...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the technical defects of power consumption on the starting resistor of the traditional technology and reducing the working efficiency of the circuit, the present invention provides a high-frequency flyback PWM control circuit for high-voltage starting

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