A Negative Feedback Circuit for Rapid Discharge of Inductive Current at Load Terminal

Abstract

The invention discloses a negative feedback circuit for rapid discharge of induced current at a load end, comprising: an induced negative pressure conduction unit used for the base voltage input terminal V when the inductive load is turned off BB When the voltage difference with the output terminal OUT reaches a preset value, an induced current signal is generated at the output terminal of the induced negative pressure conduction unit; the current mirror unit is used to generate a current signal for turning on the power tube according to the induced current signal. The mirror current signal of the negative feedback unit; the power tube negative feedback unit is used to turn on the power tube according to the mirror current signal, so that the power tube generates a feedback current signal, and reduces the inductive load on the inductive load through the feedback current signal. The rate of change of the current makes the output voltage return to zero potential. The negative feedback circuit provided by the present invention adopts the power tube as the energy discharge channel of the inductive load, which reduces the chip area, reduces the power consumption, and reduces the difficulty of the process while realizing the fast demagnetization of the inductive load, and at the same time enhances the reliability of the chip operation sex.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a negative feedback circuit for rapid discharge of induced current at a load end. Background technique [0002] In the application of integrated circuits in many fields such as aviation, navigation, and industrial control, the loads in the circuit are often strong inductive loads such as motors, relays, and transformers, such as power switching circuits. When the inductive load is turned off, due to the sudden decrease of the load current, the inductive load will produce a self-inductance to hinder the decrease of the current, thereby generating a reverse electromotive force, making the output voltage negative. This poses a huge challenge to the carrying capacity of the chip itself, as well as the drive, load open circuit protection and other modules. [0003] Traditional demagnetization circuits mostly use clamping diodes or Zener diodes as the discharge...

AI Technical Summary

Problems solved by technology

[0004] However, for high-power loads, additional clamping and bleeder channels will result in a doubled increase in chip area and doubled chip power consumption. However, due to the limited current capability of clamping diodes or Zener diodes, if the bleeder is enlarged The current will inevitably increase the chip area, which is not conducive to the reliability of the chip work, and has higher requirements for the chip design process.

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