A circuit for suppressing output overshoot and switching power supply chip

Abstract

The invention provides an output overshoot suppression circuit and a switching power supply chip, which relate to the technical field of switching power supplies, wherein the output overshoot suppression circuit includes: a comparison control module, a voltage switching module, a variable voltage generation module, and an error amplifier, so that the switch When the power chip is in abnormal working states such as power-on start-up, short-circuit recovery, and plug-in power-on, the error signal Ve can grow steadily by adjusting the reference voltage of the non-inverting terminal of the error amplifier to avoid overshooting at the system output. Therefore, under the condition that the stability of the loop and the response speed have been reasonably designed, the output overshoot problem can be solved through the circuit for suppressing the output overshoot built in the switching power supply chip.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, in particular to an output overshoot suppression circuit and a switching power supply chip. Background technique [0002] Switching power supply chips are generally divided into constant voltage chips and constant current chips. For constant voltage chips, once the resistance ratio of the external voltage divider network connected to the switching power supply chip is determined, the system output voltage VOUT is also determined according to the internal reference voltage of the switching power supply chip. Sure, but under some abnormal working conditions, the switching power supply chip will have the problem that the system output voltage VOUT exceeds the set value, which is what we often call output overshoot. [0003] Please refer to figure 1 , which is a schematic structural diagram of the sampling comparison circuit inside the switching power supply chip in the prior art. F...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the problem that the error signal Ve rises too fast when the switching power supply chip mentioned in the background technology is in an abnormal working state such as power-on start-up and short-circuit recovery, or the error signal Ve is not fully discharged during the plug-in and power-on process, thereby In order to solve the problem of overshooting of the system output voltage VOUT, an output overshoot suppression circuit and switching power supply chip are provided. When the switching power supply chip is in the above abnormal working state, by adjusting the reference voltage of the non-inverting terminal of the error amplifier EA, the error signal Ve Steady growth to avoid overshoot at system output

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