Power conversion system and control chip and power supply control circuit thereof

Abstract

The invention provides a power conversion system and a power supply control circuit and a control chip thereof. The power supply control circuit is used for supplying power to the control drive circuit, the control drive circuit is used for controlling a power device of the power conversion system, and the power supply control circuit obtains power supply input voltage by being coupled with an auxiliary winding of the power conversion system and comprises a switching circuit and a linear circuit; and the output end of the switching circuit and the output end of the linear circuit are compounded and provide power supply voltage for supplying power to the control driving circuit. According to the power supply transformation system and the control chip and the power supply control circuit thereof, the output range of the output voltage can be expanded, meanwhile, reliable power supply and lower standby loss are achieved, and higher power density and power supply efficiency are achieved.

Description

technical field [0001] The present invention relates to the field of electronics, specifically but not limited to a power conversion system and its control chip and power supply control circuit. Background technique [0002] Power converters are essential components in electronic systems. As we all know, power converters include two main types, linear converters and switching power converters, and can be divided into two types: isolated and non-isolated in terms of conversion methods. In the case of switching power supplies, isolated converters are widely used, because isolated switching power converters can protect the load from high-voltage impact and damage of the input bus, and have a wide range of applications in telecommunications wireless networks, automobiles and medical equipment. Among the various topologies of isolated converters, because the flyback converter (Flyback Converter) topology does not require an output filter inductor, has a simple circuit structure,...

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Problems solved by technology

[0004] However, in the case of PD fast charging, the output voltage Vout required by the load provided by the power conversion system has a large range of variation. For example, for PD3.0, the output voltage Vout varies from 3V to 21V, which requires the working range of the power supply voltage VDD big change

For example, when the minimum operating voltage of the power supply voltage VDD is 10V, it means that the power supply voltage VDD needs to provide a power supply voltage of 10V even when the output voltage Vout is very low, such as when the voltage is 3V. Correspondingly, when the output voltage Vout is 21V, The power supply voltage VDD may be as high as 70V, but a high power supply voltage means that the withstand voltage of the power supply voltage pin VDD is required to be high. Fever is a bigger problem

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