PWM (Pulse-Width Modulation) switching power supply control circuit with excellent anti-electromagnetic-interference capability

Abstract

The invention discloses a PWM (Pulse-Width Modulation) switching power supply control circuit with an excellent anti-electromagnetic-interference capability. The PWM switching power supply control circuit is characterized by comprising a power supply and driving module, a protection module and a multi-mode control module, wherein the power supply and driving module comprises an inner starting module, a standard voltage module, a current sampling device, an error amplifier and an output driving module; the protection module comprises an overheating protection module, an overload protection module, an overvoltage protection module and an overcurrent protection module; the multi-mode control module comprises a feedback input end, an oscillator, a load detection module for changing switching frequency, a zero-current detection circuit, a valley bottom detector for realizing a valley bottom conduction mode and a mode selector for switching a plurality of types of working modes. The PWM switching power supply control circuit disclosed by the invention adopts various methods for reducing electromagnetic interference and has a relatively good anti-electromagnetic-interference capability; a lot of peripheral circuits can be saved in an actual application process and the power supply conversion efficiency can also be greatly improved; the switching loss is reduced.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a PWM switching power supply control circuit with excellent anti-electromagnetic interference capability. Background technique [0002] Switching power supply is a high-frequency power conversion device. It is named because the device in the power supply that adjusts the voltage regulation control function always works in a switching mode. required voltage or current. The main working principle of the switching power supply is to use modern power electronics technology to control the time ratio of the switching tube on and off to maintain a stable output voltage. [0003] Usually switching power supply is composed of switching power supply control circuit and switching tube (MOSFET). The block diagram of the switching power supply is attached figure 1 As shown, there are many working modes of the switching power supply control circuit, the most common one is the pulse width ...

AI Technical Summary

Problems solved by technology

These protection measures can improve the anti-electromagnetic interference ability of the switching power supply through the design of the peripheral circuit, but doing so will make the design of the entire switching power supply more complicated, requiring the addition of many peripheral devices, resulting in an increase in the overall cost of the switching power supply

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