Gate driving circuit with self-adaptive dead time

Abstract

The invention, which belongs to the technical field of electronic circuits, provides a gate driving circuit with self-adaptive dead time, wherein the gate driving circuit is suitable for a switch power supply circuit. With control by a drive logic control circuit, crossed condition of high-end and low-end driving units is realized, so that the self-adaptive dead time function is realized. A level shift circuit enables a control signal generated by the drive logic control circuit to be lifted to a power rail with high-end driving; and a bootstrap circuit generates the power rail with high-end driving by means of a charge pump. A first driving enhancement circuit and a second driving enhancement circuit enhance drive control signals to be gate drive signals with ampere levels. A power drive stage of the switch power supply circuit is connected to a gate drive signal generated by a gate drive circuit and an output voltage Vout is generated. According to the invention, the dead time is adjusted adaptively based on the dimension of the power tube to avoid penetration; and the control way is simple and self-adaptive dead time control is realized with low costs; and the universality is high.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to a gate drive circuit with self-adaptive dead zone time. Background technique [0002] In the switching power supply circuit using synchronous rectification technology, in order to ensure that the upper and lower tubes are not turned on at the same time, so as to avoid damage to the circuit, it is necessary to set a dead time during the switching conversion process to protect the safe operation of the circuit. [0003] Such as figure 1 Shown is the gate drive circuit for the switching power supply circuit. The power driving stage in the switching power supply circuit includes a switching tube M1, a rectifying tube M2, an inductor L and a capacitor C. Both the switching tube M1 and the rectifying tube M2 are NMOS power tubes. The drain of the tube M1 is connected to the input voltage Vin, its source is connected to the drain of the rectifier tube M2 and connected to the ...

AI Technical Summary

Problems solved by technology

[0010] Although the traditional fixed dead time is relatively simple in design, in order to ensure that the upper and lower power tubes will not break through under all conditions, the dead time needs to be designed quite long, which will inevitably result in a long time body The diode conducts, increasing the power loss

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