Switching power supply control circuit having loop compensation function

Abstract

The invention discloses a switching power supply control circuit having a loop compensation function. The switching power supply control circuit includes a control chip where an amplifier is integrated. A resistance-capacitance network double-pole compensation circuit is connected between a first pin and a second pin of the control chip, and the resistance-capacitance network double-pole compensation circuit is connected with a first resistor and a second resistor to be used for sampling signals. A soft-start circuit is connected between the first pin and an eighth pin of the control chip; anoscillating circuit is connected between the eighth pin and a fourth pin of the control chip, and a sixth pin of the control chip is connected with a switching tube. A third pin is connected with an RC filter circuit composed of a resistor and a capacitor. A seventh pin of the control chip is connected with a VCC. A fifth pin of the control chip is in grounded connection. Compensation is made fora control loop of a switching power supply through the double-pole compensation circuit. The circuit is simple and ingenious in design, the reliability of the operation of the switching power supply control circuit is ensured, and the switching power supply control circuit is simple in structure and low in cost and can improve the working performance, safety and reliability of an entire system.

Description

technical field [0001] The invention belongs to the technical field of switching power supply control, and in particular relates to a switching power supply control circuit with loop compensation. Background technique [0002] Switching Mode Power Supply (Switching Mode Power Supply), also known as switching power supply, switching converter, is a high-frequency power conversion device. Its function is to convert a level of voltage into the voltage or current required by the user through different forms of architecture. [0003] Switching power supply is a kind of power supply that uses modern power electronic technology to control the time ratio of switching on and off to maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. With the development and innovation of power electronics technology, switching power supply technology is constantly innovating. At present, switching power supply is wide...

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Problems solved by technology

And as the switching frequency increases, the transfer function gain increases accordingly, but the phase angle will decrease. If it is not filtered out (compensated), positive feedback will be formed, which will invalidate the control system of the entire switching power supply and cause damage to the entire circuit.

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