Power converter and switch control module therein

Abstract

The invention discloses a power converter and a switch control module therein. The power converter includes: a transformer having a primary side winding to receive a rectified voltage, and a secondary side winding to generate an output DC voltage; a gallium nitride (GaN) M0SFET, coupled to the primary side winding for controlling a primary side current flowing through the primary side winding; a sensing resistor coupled to the GaN transistor switch, for sensing the primary side current to generate a current sensing signal; and a switch control unit, for controlling the GaN transistor switch according to the current sensing signal. The sensing resistor and the GaN transistor switch are connected at a ground node having a voltage level which is the ground of the primary side.

Description

technical field [0001] The present invention relates to a power converter capable of reducing ringing effect and a switch control module therein, wherein a gallium nitride transistor switch is coupled to a sensing resistor through a node corresponding to the primary side grounded, so as to Reduce the effect of parasitic inductance in the line on fast switching elements. Background technique [0002] refer to figure 1 , which shows a power converter 10 of the prior art, comprising: a transformer 11 having a primary winding 111 to receive a rectified voltage Vp and a secondary winding 112 to generate a DC output voltage Vo; The switch M0 is coupled to the primary winding 111 to control the current Ip passing through the primary winding 111; and a switch control unit 12 has a switch control pin Gate, a current sensing pin CS, and a grounding pin GND. The current sensing pin CS is coupled to the switch M0, and is also coupled to the ground Gp of the primary side via a resisto...

AI Technical Summary

Problems solved by technology

[0003] When the switch M switches between conduction and non-conduction at high frequency, the current sense pin CS is coupled to the line of the primary ground Gp, and the ground pin GND is coupled to the line of the primary ground Gp , there will be an obvious parasitic inductance effect, causing the control signal of the switch M0 (that is, the voltage signal output by the switch control pin Gate) to have an oscillation effect (Ringing effect). This oscillation effect may cause the switch M0 to lose control, and the current Ip will also out of control

In a runaway state, in addition to ineffective power conversion, it may also damage the circuit

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