Improved light load detection circuit

Abstract

The invention relates to the technical field of circuits, in particular to an improved light load detection circuit, which comprises a voltage and current conversion module, wherein an input end of the voltage and current conversion module is connected with a first power supply voltage and a second power supply voltage, and the voltage and current conversion module is used for calculating a voltage difference between the first power supply voltage and the second power supply voltage and converting the voltage difference into current; a current mirroring module the input end of which is connected to the output end of the voltage and current conversion module, wherein the current mirroring module is used for copying the current to form threshold current and outputting the threshold current; a load detection module the input end of which is connected to the output end of the current mirror image module, wherein the load detection module is used for detecting whether the load is in a light load state or not according to the threshold current. The light load detection circuit has the beneficial effects that the output threshold current is changed along with the change of the first power supply voltage, so that the change of the first power supply voltage can be compensated, the purpose of keeping the threshold current relatively constant is achieved, an external device and an additional chip pin do not need to be added, and the cost is reduced.

Description

technical field [0001] The invention relates to the field of circuit technology, in particular to an improved light-load detection circuit. Background technique [0002] In many switching power supply applications, lithium-ion batteries are more and more widely used, product performance is improving and power consumption is also increasing. In order to prolong the use time of a single charge, the efficiency of power management is becoming more and more efficient. Many products require light load. Automatically enter standby mode or shutdown mode to reduce power consumption, thereby prolonging battery life, for which light-load automatic detection came into being. [0003] In the prior art, although a light-load detection circuit is proposed, the technical solution for its implementation is too complicated, especially when it is applied to charge a capacitor through a current source, causing the current source to charge the capacitor to be relatively fixed. This leads to the...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, although a light-load detection circuit is proposed, the technical solution for its implementation is too complicated, especially when it is applied to charge a capacitor through a current source, causing the current source to charge the capacitor to be relatively fixed. This leads to the problem that the output threshold current cannot be kept relatively constant when the light load exits under different battery voltage conditions

Therefore, it has become a difficult problem to be solved urgently for those skilled in the art to solve the above-mentioned problems such as the threshold current cannot be kept relatively constant.

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