Method for detecting load current

Abstract

The invention discloses a method for detecting a load current. In the prior art, an existing load current detection error is large. In the invention, the above problem is mainly solved. The method comprises the following steps of (S1) accessing a threshold voltage VS0-deltaV0 provided with a voltage threshold to a positive input end of a comparator, and accessing a VS voltage of a voltage on a detecting capacitor C to a negative input end of the comparator; (S2) comparing the threshold voltage VS0-deltaV0 with the VS voltage in a fixed time interval through the comparator; and (S3) when the VSvoltage is less than the threshold voltage VS0-deltaV0, outputting a high level by the comparator, wherein at this time, the voltage of the capacitor C drops significantly, which indicates that the load current of a load connected to the capacitor C is large, otherwise, the load current of the load connected to the capacitor C is small. In the above scheme, the load current in a circuit can be accurately determined and a high practical value and a high popularization value are achieved.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a method for detecting load current. Background technique [0002] In the charging system, it is generally judged by detecting the magnitude of the load current whether the load terminal is fully charged or whether it has been unplugged. The existing technology basically judges the load size by directly sampling the current on the charging path. There are two general methods: the first is to connect a sense resistor in series on the charging path, and the circuit will measure the voltage across the sense resistor. The second is to directly sample the voltage difference between the two ends of the isolation tube. The first way (such as figure 1 As shown), the charging device controls the entire charging process by controlling the gate VDRV voltage of the isolation tube. In order to stabilize the input voltage of the charging load, a load capacitor of seve...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for detecting load current, which mainly solves the problem of large detection error of existing load current existing in the prior art

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