Flyback switching power supply circuit

Abstract

The invention discloses a flyback switching power supply circuit. The flyback switching power supply circuit comprises a multi-path output power supply, a feedback loop, a power supply controller module, a first switch and an active clamping control circuit; the multi-path output power supply comprises an input power supply, a transformer, a main output and an auxiliary output, and the main outputand the auxiliary output are coupled and connected with the input power supply through the transformer; the feedback loop is connected with the main output and is used for generating a feedback signal based on a voltage signal of the main output; the power supply controller module is connected with the feedback loop and is used for generating a PWM signal based on the feedback signal; the first switch is connected with the power supply controller module and is used for controlling the input power supply to supply power to the main output and the auxiliary output based on the PWM signal; and the active clamping control circuit which is connected with the power supply controller module and is used for controlling the voltage value of the auxiliary output based on the PWM signal. Thus, the voltage cross adjustment rate of multipath output of the switching power supply circuit can be effectively improved.

Description

technical field [0001] The invention relates to a power supply circuit, in particular to a flyback switching power supply circuit. Background technique [0002] With the rapid development of power electronics technology, switching power supplies have entered various electronic and electrical equipment fields one after another. For example, switching power supplies have been widely used in program-controlled switches, communications, electronic testing equipment power supplies, and control equipment power supplies. [0003] In related technologies, flyback switching power supplies are often used for multi-channel power output. For example, when a single-transformer flyback switching power supply is used for multiple output voltages, the channel with low output voltage and large output current change is usually used as the closed-loop main feedback control. , the output voltage of other auxiliary circuits has no feedback regulation. Because the magnetic core of the flyback tr...

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Problems solved by technology

Because the magnetic core of the flyback transformer needs to open an air gap (to prevent transformer saturation) and the limitation of the winding process leads to the existence of leakage inductance, the greater the leakage inductance, the worse the coupling between the primary and secondary sides, plus the resistance of the winding and the current loop Influenced by parasitic parameters, when the load difference between the output voltage of the main circuit and the auxiliary circuit is large, the amplitude of the output voltage of the auxiliary circuit changes greatly

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