A gate drive circuit with adaptive dead time

Abstract

The invention relates to a gate drive circuit for self-adaptive dead zone time, which belongs to the technical field of electronic circuits. Applicable to switching power supply circuits, the drive logic control circuit controls the high-end and low-end drive cross-conduction, and realizes the function of adaptive dead time; the level shift circuit lifts the control signal generated by the drive logic control circuit to the power rail of the high-end drive ; The bootstrap circuit generates a high-side driven power supply rail by means of a charge pump; the first drive enhancement circuit and the second drive enhancement circuit enhance the drive control signal to a gate drive signal with an ampere level; the power drive stage of the switching power supply circuit is connected The gate drive circuit generates a gate drive signal and generates an output voltage Vout. The invention can self-adaptively adjust the dead time according to the size of the power tube to ensure avoidance of punch-through; the control mode is simple, and the purpose of self-adaptive dead time control is realized at a very small cost, and has extremely high versatility.

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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