A highly reliable gate drive circuit with adaptive dead time

Abstract

A high-reliability adaptive dead-time gate drive circuit, the high-end gate drive module generates a high-end logic signal according to the high-end drive logic control signal and the low-end power tube gate drive signal, and introduces a low-end anti-penetration feedback signal, Make the high-end gate drive module turn on the high-end power tube only when the high-side drive logic control signal is high, the gate drive signal of the low-side power tube is low, and the low-side anti-penetration feedback signal is low; The low-side logic signal is generated by the high-side drive logic control signal, the dead zone detection signal, the signal at the connection between the high-end power tube and the low-side power tube, and the low-side anti-penetration feedback signal is introduced at the same time. Only when the low-side drive logic control signal is high and dead zone When the detection signal is low, the signal at the junction of the high-end power tube and the low-end power tube is low, and the high-end anti-penetration feedback signal is low, the low-end power tube is turned on. The invention can self-adapt to the dead zone time, and avoids turning on the high-end power tube and the low-end power tube at the same time.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and relates to a gate drive circuit with high reliability and adaptive dead time. Background technique [0002] The gate drive circuit of the power switch tube is one of the core circuits of chips such as power conversion and LED drive. The characteristics of the drive circuit directly affect the safety, reliability and performance indicators of the switching power supply. 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. Although the traditional fixed dead time is relatively simple in design, in order to ensure that the upper and lower power tubes do not break through under all conditions, the dead time n...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the problem that the dead time design in the traditional fixed dead time detection technology is too long to increase the power loss, and the problem that the high-end power tube gate drive signal and the low-end power tube gate drive signal are likely to overlap, the present invention A gate drive circuit is proposed, which adopts an adaptive dead-time driving strategy to avoid problems such as power loss caused by too long or too short dead-time, so that the power tube can realize reliable switching action; in addition, the present invention also The non-overlap timing structure is added, so that even when the high-side drive logic control signal H_ctrl and the low-side drive logic control signal L_ctrl overlap, it can still ensure that the high-end power tube and the low-side power tube in the switching power supply will not be turned on at the same time, ensuring Reliability of Adaptive Dead Zone Driver Circuit

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