A control method for improving the output precision of a switching power supply

Abstract

A control method for improving the output accuracy of a switching power supply in accordance with an embodiment of that present invention, precision control module, error calculation module, the PID module and the PWM module constitute the control system, the control system is connected with the controlled switching power supply to form a closed loop, By detecting an output voltage control mode switch, When the output voltage exceeds the upper limit voltage, the circuit enters the DCM mode by mode switching to reduce the input energy so as to stabilize the output voltage in the regulating range. When the output voltage is lower than the lower limit voltage, the circuit enters the CCM mode by mode switching to increase the input energy so as to quickly restore the output voltage to the regulating range. In the normal regulation process, the output voltage is limited between the upper limit voltage and the lower limit voltage, the voltage output ripple is reduced, and the accuracy is improved.

Description

technical field [0001] The invention relates to a switching power supply, in particular to a control method for improving the output precision of the switching power supply, which can reduce the output ripple of the switching power supply and improve the output precision of the switching power supply. Background technique [0002] Switching power supplies are usually used as power supplies for various types of electrical equipment to convert unadjusted AC or DC input voltages into adjusted AC or DC output voltages. Since the switching power supply needs to adapt to different working conditions, the output accuracy performance requirements of the power supply are getting higher and higher. As the size of the process gradually decreases, the withstand voltage of the devices in the chip also decreases. If the power supply voltage is too large at this time, it is easy to cause damage to the chip device due to excessive voltage or excessive power consumption, while the output of ...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the limitations and deficiencies of the prior art, the present invention proposes a control method for improving the output precision of the switching power supply, which belongs to the steady-state regulation. Aiming at the problem of large output ripple and low precision of the system under stable output load, corresponding solutions are proposed. The algorithm can limit the overshoot and undervoltage of the output voltage within a certain range, reduce the output ripple, and improve the output accuracy. It will not cause system instability in multi-mode control, making the output accuracy of the circuit better.

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