Fast charging circuit based on discrete depletion type GaN device

Abstract

The invention discloses a fast charging circuit based on a discrete depletion type GaN device. The fast charging circuit comprises an alternating current power supply, a rectifier bridge, an input electrolytic capacitor, a transformer, an absorption circuit, an output rectifier tube, an output capacitor, a load, a GaN HEMT tube and a low-voltage silicon tube. According to the invention, the cascade form of the discrete high-voltage D mode GaN device and the low-voltage silicon device is adopted, and the external capacitor is used for compensating the mismatching of the capacitor, so that the low-voltage silicon can work in a reasonable voltage interval.

Description

technical field [0001] The invention relates to the technical field of fast charging circuits, in particular to a fast charging circuit based on discrete depletion-type GaN devices. Background technique [0002] With the development of communication technology, consumers have higher and higher requirements for mobile phone chargers. Small size and high efficiency are the main demands of consumers. Fast charging technology has emerged as the times require. The current fast charging technology mainly uses such figure 1 In the flyback converter shown, there are currently three main solutions for the main switch S11: 1. Directly use high-voltage Si devices; 2. Use E mode GaN devices; 3. Use D mode GaN packaged cascode devices. [0003] The disadvantage of Option 1 is that the frequency cannot be increased, the loss is large, and the efficiency is low; the disadvantage of Option 2 is that the driving voltage range is relatively narrow, and there is a risk of reliability; the disa...

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Problems solved by technology

[0003] The disadvantage of Option 1 is that the frequency cannot be increased, the loss is large, and the efficiency is low; the disadvantage of Option 2 is that the driving voltage range is relatively narrow, and there is a risk of reliability; the disadvantage of Option 3 is that the ceramic substrate used for sealing is expensive, and the cost of sealing is high. D mode GaN and LV silicon devices have capacitance matching problems, and debugging is not flexible

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