Adaptive Dead Zone Generation Circuit for Switching Converter Based on Body Diode Conduction Detection

Abstract

The invention relates to a switching converter self-adaptive dead zone generation circuit based on body diode conduction detection, which belongs to the technical field of electronic circuits. The voltage comparator compares the signals at its first and second input terminals, and outputs the comparison signal. The adaptive dead zone logic circuit extracts the conduction signal of the body diode in the comparison signal as the shutdown signal of the power tube, and outputs it to the dead zone selection judgment circuit; the dead zone selection judgment circuit processes the fixed dead zone and the adaptive dead zone according to the working mode of the switching converter, and then the signal is input to the power tube drive circuit to ensure that both the continuous mode CCM and the discontinuous current mode DCM It can output an ideal driving signal with adaptive dead zone. The invention can effectively detect the conduction condition of the body diode in the switch converter, and turn on the power tube based on this, realizing the near ideal dead zone time.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to an adaptive dead zone generation circuit for a switching converter based on body diode conduction detection. Background technique [0002] In a DC-DC switching converter with synchronous rectification, the size of the two power transistors is usually large, and the turn-on and turn-off delays cannot be ignored. If a single control signal is used for switching control, two power transistors will be turned on at the same time. , the current flowing through the power tube will be very large, especially in high-frequency applications, the power consumption of the chip will be greatly increased, the common solution is to divide the control signal into two and add dead time, dead time That is, the time when two power tubes are turned off at the same time. [0003] For dead time processing, the traditional solution is to use a fixed length of dead time, which has the advantag...

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Problems solved by technology

At present, there are not many methods to set the dead time by detecting the conduction of the body diode. The literature Zhen S, Zhang B, Luo P, et al.A high efficiency synchronous buckconverter with adaptive dead time control for dynamic voltage scaling applications[C] / / Ieee / ifip, International Conference on Vlsi and System-On-Chip.IEEE, 2011:43-48. involves a method of measuring the conduction of the body diode, but this method has poor versatility, and the requirements for the process higher disadvantage

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