A composite multifunctional ocp control circuit

Abstract

The invention discloses a composite multifunctional novel OCP control circuit. The composite multifunctional novel OCP control circuit comprises OCP DC voltage input, sampling-end voltage input, an OCP compensation circuit, a logic control circuit, a simulation adder, a comparator and a current pump circuit, wherein the input end of the current pump circuit is connected with the output end of the logic control circuit, the output end of the current pump circuit and the output end of the simulator adder are connected with the same input end of the comparator, the current pump circuit outputs currents periodically changing in oscillation mode according to PWM signals output by the logic control circuit, and output voltages of the simulator adder generate periodical oscillation change along with output currents of the current pump circuit; and the comparator compares the sampling-end voltage input and output voltages of the simulation adder and outputs corresponding logic level to the logic control circuit to enable the logic control circuit to output the corresponding PWM signals so as to control a power switch of a switch power supply. According to the invention, the load carrying capacity of the switch power supply is enhanced, and overpower protection of the switch power supply is also accelerated.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a composite multifunctional OCP control circuit. Background technique [0002] With the increasing demand for switching power supplies, the main control chip of the power supply has more stringent requirements for reducing costs, increasing functions, and optimizing performance. For some specific applications, such as mobile phone chargers, under the condition of full-range AC input (90V / 60Hz~264V / 50Hz), it is necessary to ensure that the maximum output power has a high consistency, and it is also required that the output overpower protection point and The power difference corresponding to the recovery point is as small as possible, and at the same time, higher requirements are put forward for the response speed of the output overpower protection. [0003] Assume the system works in discontinuous mode (DCM). In an ideal state, the output power formula: Lp is the p...

AI Technical Summary

Problems solved by technology

This leads to the following two significant problems in the prior art: First, the power corresponding to the output over-power protection point and the recovery point is quite different, and the user needs to set the output over-power protection point to be much larger than the rated output power. In order to ensure that the normal start-up is completed under the rated full-load output state

Second, the response speed of the output overpower protection is not fast enough, and it may be due to the balance between the reduction of the output voltage and the reduction of the operating frequency, resulting in the failure of the normal protection of the output overpower

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