Configurable over-temperature protection circuit applied to switching power supply

Abstract

The invention relates to a configurable over-temperature protection circuit applied to a switching power supply. The configurable over-temperature protection circuit is composed of a biasing circuit,an over-temperature detection module, and a trimming circuit. The biasing circuit obtains a biasing current independent of a power supply voltage under the effect of the power supply voltage and outputs the biasing current to the over-temperature detection module; and the trimming circuit receives the power supply voltage and an externally inputted trimming voltage, obtains a trimming signal, andoutputs the trimming signal to the over-temperature detection module. The over-temperature detection module receives the power supply voltage and the biasing current and adjusts the detection resistance in the over-temperature detection module based on the trimming signal to adjust an over-temperature point; when the ambient temperature exceeds the over-temperature point, state overturning is carried out on an over-temperature protection signal outputted to a switching power supply drive module and thus the switching power supply circuit is turned off. According to the configurable over-temperature protection circuit, over-temperature point configuration can be carried out based on a practical application environment; and the over-temperature point configuration precision can be set. The over-temperature point can be configured dynamically based on needs of application environments, so that the application range and the configuration precision of the over-temperature protection circuitare improved.

Description

technical field [0001] The invention relates to an over-temperature protection circuit, in particular to a configurable over-temperature protection circuit applied in a switching power supply with a wide temperature range, and belongs to the field of switching power supply protection circuits. Background technique [0002] The power consumption of switching power supply is generally very low, but after the adjustment tube in the circuit is packaged, as a heating element, it may appear high temperature for a long time under load, causing damage to the chip, so it is necessary to design an over-temperature protection circuit to prevent Cause thermal damage to other parts of the chip, and even cause greater harm. [0003] The over-temperature point of the existing over-temperature protection circuit cannot be changed according to the requirements of the application environment, which limits the application range of the over-temperature protection circuit. Contents of the inve...

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Problems solved by technology

[0002] The power consumption of switching power supply is generally very low, but after the adjustment tube in the circuit is packaged, as a heating element, it may appear high temperature for a long time under load, causing damage to the chip, so it is necessary to design an over-temperature protection circuit to pr

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