Motor drive circuit with dead band time delay

Abstract

The invention discloses a motor drive circuit with dead band time delay. The motor drive circuit comprises an H-bridge circuit connected with a motor. The H-bridge circuit is controlled by a photoelectric isolating circuit, a dead band time delay control circuit and a half-bridge drive control circuit and controls the steering of the motor through adjusting breakover and the check time order of an MOS tube. A pair of complementary input signals are output through a double-path photoelectric coupler, and two paths of signals enter the dead band time delay control circuit. Control signals complementary with two alternative denial gate output paths are in concatenation through two paths. Signals output by the dead band time delay control circuit are respectively input to two symmetric units in the half-bridge drive control circuit. The dead band delay control circuit controls the time of a dead band, and simultaneous breakover of two MOS tubes of the same arm is prevented. Dead band time can be adjusted flexibly. The photoelectric isolating circuit increases anti-interference capacity, and reduces interference of H-bridge control signals to a front-grade circuit when an H-bridge outputs large currents in an instant state or a motor is started. The motor drive circuit can work with power supplied by a single power supply.

Description

[0001] technical field [0002] The invention relates to a motor drive circuit, in particular to a motor drive circuit with dead zone delay, and belongs to the technical field of circuits. Background technique [0003] The power drive circuit of the motor is usually driven by an H-bridge structure circuit. The H-bridge circuit is composed of four power switch MOS tubes. A control structure is used to control the conduction and cut-off of the four switch tubes, so that the motor rotates forward and reverse. turn or stop. After adding complementary signals to the power switch MOS tubes of the upper and lower bridge arms of the H-bridge drive circuit, the turn-off time of the power switch MOS tubes is usually longer than the turn-on time under load conditions. In this way, the power switch MOS tubes of the lower bridge arm are not turned off in time When the upper bridge arm is first opened, the so-called "bridge arm through" fault will occur. This will cause the current to i...

AI Technical Summary

Problems solved by technology

The purpose is to overcome the defects of dual power supply, possible direct connection of the upper and lower bridge arms, and low anti-interference ability in the prior art.

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