Switching power supply unit

Abstract

A switching power supply device (100) is provided, comprising: a normally-on transistor (12), a normally-off metal-oxide-semiconductor field-effect transistor (MOSFET) (14), a normally-off MOSFET (14) and a normally-on The source terminal (12S) of the transistor (12) is connected in series, and the driver (16), is connected to the gate terminal (12G) of the normally-on transistor (12) and is arranged to drive the normally-on transistor ( 12) the gate (12G). A switching transistor (28) may then be located between the source terminal (12S) of the normally-on transistor (12) and the common connection (30) of the driver (16) to protect the switching power supply device (100) from harmful The effect of overvoltage and overcurrent peaks.

Description

technical field [0001] The present invention relates to switching power supply devices, particularly switching power supply devices for controlling consumer electronic products or systems. Background technique [0002] Various products and systems such as televisions, electric vehicles, radar systems, motor controllers and uninterruptible power supply systems require a relatively large supply of electrical power, which is usually delivered from a high voltage power source. Various types of semiconductor field effect transistors (FETs) can be used as power switches to perform switching functions required by a product and / or system. [0003] Semiconductor FETs rely on silicon materials and technology. A typical FET will include source and drain terminals for connecting the power supply to the load. Then there is another terminal in FET located between source terminal and drain terminal, known as gate and this gate terminal controls the gate in FET located between source term...

AI Technical Summary

Problems solved by technology

However, this approach has an obvious disadvantage: there is an uncertainty in the potential between the source terminal 12S of the GaN transistor 12 and the source terminal 14S of the MOSFET 14

Voltage peaks above the permissible drain voltage range of low-voltage silicon transistors may occur, and as a result, transistors and other components of the circuit may be damaged, e.g. Figure 1b in the arrangement shown

Furthermore, in a standard cascode configuration, in order to handle large currents on the order of tens of amperes, specific silicon MOSFETs with large gate charges and capacitances must be used, and this usually cannot support efficient high-frequency switching operation

[0014] Adding parallel zener diodes to limit these peaks adds extra capacitance to charge and discharge during each switching cycle, which in turn increases switching losses in the switching power supply unit

An ideal switching power supply unit would switch between on and off states instantly with 0 power loss

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