Load Tail Current Elimination Circuit

Abstract

An embodiment of the present invention provides a load tail current elimination circuit, including: an inductive load, a first switch tube, a second switch tube, an internal drive unit, and an absorption unit; the inductive load, the second switch tube, and the first switch tube are connected in series Connected between the positive pole and the negative pole of the DC power supply; the internal drive unit is connected in series between the positive pole of the DC power supply and the first switch tube, and the internal drive unit includes a drive voltage output terminal connected to the control pole of the second switch tube; the absorption unit is connected to Between the inductive load and the connection node of the second switch tube and the test ground, and used for consuming the tail current of the inductive load when the second switch tube is turned off. The embodiments of the present invention can quickly turn off the tail current when the load is disconnected without adding additional control resources.

Description

technical field [0001] The embodiments of the present invention relate to the field of electronic technology, and more specifically, to a load tail current elimination circuit. Background technique [0002] For inductive load circuits, PWM (Pulse Width Modulation, pulse width modulation) is often used for current regulation, so that only one voltage can be used to adjust the magnitude of the current by changing the duty cycle. But for some applications, when the load is turned off, the current needs to drop to 0 rapidly. [0003] The traditional PWM control inductive load current uses a freewheeling circuit, such as figure 1 As shown, when the switch tube Q1 is turned on, the current path is 11 ; when the switch tube Q1 is turned off, the current path is 12 . In this way, the current on the inductive load can be kept at the required value through a higher carrier frequency, and different currents can be obtained by changing the duty cycle of the carrier. The current wavefo...

AI Technical Summary

Problems solved by technology

[0007] The embodiment of the present invention provides a load tailing current elimination circuit, which aims to solve the problem that more control resources are required to quickly turn off the load current in the prior art, and when single control is adopted, the tailing time of the freewheeling current of the diode is very short. Long, unable to meet the needs of some occasions that require rapid current shutdown

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