An ultra-high precision overpower compensation circuit

Abstract

The invention discloses an ultra-high-precision overpower compensation circuit, which includes a ramp voltage generator circuit, a time parameter setting circuit, a ramp voltage sampling and holding circuit, a ramp voltage compensation circuit and an overpower point comparison circuit, and a ramp voltage generation circuit. The device circuit, the ramp voltage sampling and holding circuit, the ramp voltage compensation circuit and the overpower point comparison circuit are sequentially connected, the time parameter setting circuit is connected with the ramp voltage generator circuit and the ramp voltage compensation circuit, the ramp voltage generator circuit, The slope voltage sampling and holding circuit and the slope voltage compensation circuit are externally connected to the PWM signal output by the switching power supply control unit, and the overpower point comparison circuit is externally connected to the CS port of the switching power supply control unit. Applying the ultra-high-precision overpower compensation circuit of the present invention to a switching power supply can reasonably change the threshold voltage of the peak current of the primary coil of the transformer under different input voltages, thereby making up for the difference caused by the difference in the maximum input power point under different input voltages. influences.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to an ultra-high-precision overpower compensation circuit applied to switching power supplies. Background technique [0002] With the strong consumer demand for electronic products and the upgrading of various electronic products, the requirements for power modules are getting higher and higher. The power module usually provides constant voltage or constant current to the functional modules to ensure their stable operation. [0003] Under full-range AC input conditions, whether it is high-precision output power or high-precision output current, it is required that the peak current difference flowing through the primary inductance of the transformer must be as small as possible under high or low AC input conditions. For the convenience of illustration, it is assumed that the system works in discontinuous mode (DCM). In an ideal state, after the primary inductance curren...

AI Technical Summary

Problems solved by technology

[0005] In actual work, when CS detects that the current sampling voltage value reaches the threshold voltage Later, there is a delay time for the internal control signal to turn off the power tube

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