A dv/dt noise detection and elimination circuit

Abstract

A dv / dt noise detection and elimination circuit is used in a bridge circuit, the bridge circuit includes N groups of bridge arms, each group of bridge arms includes an upper power tube and a lower power tube, and N is a positive integer; dv / dt noise detection and The elimination circuit includes N dv / dt noise detection and elimination units, which are respectively used to detect and eliminate the dv / dt noise of N groups of bridge arms in the bridge circuit; the i-th dv / dt noise detection and elimination unit includes a first resistor, The first capacitor and the first NMOS transistor, the drain of the first NMOS transistor is connected to the gate of the lower power transistor in the i-th group of bridge arms, and the gate of the first NMOS transistor is connected to the i-th group of bridge arms after passing through the first capacitor. The drain of the middle and lower power transistors, on the other hand, is connected to the source of the first NMOS transistor and the source of the middle and lower power transistors of the i-th bridge arm through the first resistor, i∈[1,N]. The invention can detect this phenomenon when the bridge circuit is affected by a large dv / dt and cause the power tube to trigger falsely, and start to eliminate the influence of dv / dt, effectively reducing the possibility of bridge arm through-through, and improving the efficiency of the bridge circuit. reliability.

Description

technical field [0001] The invention belongs to the technical field of power integrated circuits, and relates to a solution to dv / dt noise interference of a high-voltage bridge drive circuit, in particular to a dv / dt noise detection and elimination circuit. Background technique [0002] Today, as the development of science and technology tends to be automated and intelligent, motors have been applied to various fields of social production and life, and the performance of motor drive circuits has also received more attention. The bridge circuit is the core unit of the motor drive circuit, and its performance directly affects the overall performance and stability of the drive circuit. [0003] Taking the half-bridge circuit as an example to illustrate, the structure of the commonly used half-bridge circuit is as follows: figure 1 As shown, the two groups of bridge arms of the half-bridge circuit are the upper power transistor MN1 and the lower power transistor MN2, the upper ...

AI Technical Summary

Problems solved by technology

[0005] In view of the lack of research on the dv / dt noise in the bridge circuit in the above-mentioned existing solutions, there is no simple and effective method to solve the problem that excessively high dv / dt may cause the power tube of the bridge circuit in the off state to turn on by mistake, thereby Cause the bridge arm to pass through directly, and the large current through the pass will cause the problem of burning the power tube. The present invention analyzes the cause of the dv / dt noise generated by the bridge circuit, and proposes a dv / dt noise detection and elimination circuit, which can be applied to the bridge circuit, the dv / dt noise detection and elimination unit is targetedly applied to the specific structure of the bridge circuit to improve specific parameters, and can achieve better anti-dv / dt noise ability

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