NMOS power tube gate driving module, driving circuit and switching power supply

Abstract

The invention provides an NMOS power tube gate driving module, a driving circuit and a switching power supply, and relates to the technical field of switching power supplies, and the NMOS power tube gate driving module is realized by adopting a transistor integrated circuit process. The internal circuit of the NMOS power tube gate driving module is simple, and the NMOS power tube gate driving module is suitable for a switching power supply driving circuit and a boost switching power supply. By quickly opening and closing the NMOS power tube, the problem of large opening and closing loss when the NMOS power tube is applied to a switching power supply chip is solved, and the NMOS power tube gate driving module has an over-current detection function and has the advantages of simple structure, low cost and high reliability.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, in particular to an NMOS power transistor grid drive module, a driving circuit and a switching power supply. Background technique [0002] The power tube inside the switching power supply chip has two types: power triode and power MOS tube. The power MOS tube is divided into PMOS power tube and NMOS power tube. The control circuit of the tube as a switch tube is completely different. [0003] Different types of power MOS tubes have different internal majority carriers when they work, and the on-resistance Rdson of NMOS power tubes is smaller than that of PMOS power tubes under the same unit area. In the case of the same on-resistance Rdson, the inter-electrode parasitic capacitance Ciss of the NMOS power transistor is smaller than that of the PMOS power transistor. The greater the on-resistance Rdson of the power MOS tube, the greater the conduction loss of the switching power ...

AI Technical Summary

Problems solved by technology

[0004] When an NMOS power tube is used as a power switch tube in a switching power supply chip, the drive circuit of the NMOS power tube often needs to add an external BOOST capacitor to provide a stable power supply for the drive circuit, and a corresponding capacitor charging circuit, level shifting circuit and Drive circuit, the internal circuit structure is complex

Moreover, in the prior art, overcurrent detection usually realizes overcurrent protection by sampling part of the power tube current and calculating the current value of the entire chip power tube through proportional conversion. The problem of poor current accuracy

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