Control circuit of switching power supply

Abstract

The invention discloses a control circuit of a switching power supply, and belongs to the technical field of over-current protection of the switching power supply. The control circuit of the switching power supply comprises a voltage stabilization circuit, a time-delay circuit, a regulating circuit and a detection circuit, wherein the time-delay circuit is respectively connected with the voltage stabilization circuit and the regulating circuit; the regulating circuit is connected with the detection circuit; the voltage stabilization circuit is connected with the voltage output end of the switching power supply; the voltage stabilization circuit is used for suppressing the output voltage of the switching power supply to be a preset voltage value; the time-delay circuit controls the on-off of the regulating circuit by regulating the voltage; the regulating circuit enables the detection circuit to work in a high-resistance state or in a low-resistance state by the on-off of the regulating circuit; the detection circuit comprises a current generation element; the current generation element generates a corresponding detection current according to an output current of the switching power supply; the detection circuit outputs the detection voltage. The control circuit of the switching power supply has the advantages that the over-current protection capacity is not lowered while the switching power supply improves the capacitive load capacity, achievement is easy, and the achievement cost is low.

Description

technical field [0001] The invention relates to the technical field of switching power supply overcurrent protection, in particular to a switching power supply control circuit. Background technique [0002] As the integration of electronic products becomes higher and higher, an electronic product may include several or even dozens of functional modules, thus requiring the power adapter to provide several amperes or even tens of amperes of current. Often in this case, a large-capacity load capacitor needs to be connected to the output of the power adapter to prevent the output voltage from causing a voltage jump when the load changes. The capacitance of the above-mentioned external capacitor is usually several thousand microfarads (μF) . In addition, some Netcom products in the prior art, such as DSL (Digital Subscriber Line, Digital Subscriber Line) products, are billed by time, which requires adding a Dying gasp function to these Netcom products. The so-called Dying gasp ...

AI Technical Summary

Problems solved by technology

The above technical solution also only discloses the composition of the overcurrent protection unit, which cannot solve the problems in the prior art

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