Semiconductor device

Abstract

A semiconductor device capable of short-circuiting a gate-source capacitance of a FET (Field Effect Transistor) as a main switching device with low impedance is proposed. The above semiconductor device includes a first FET, a second FET, and a package. Both the first FET and the second FET are contained within the package. The first FET constitutes a main switching device. The drain and source of the second FET are connected to the gate and source of the first FET. An outer surface of the package has external terminals of the first and second FETs.

Description

technical field [0001] The present invention relates to a semiconductor device using a plurality of field effect transistors (hereinafter referred to as FETs) and a DC-DC (direct current-direct current) converter using the semiconductor device in a synchronous rectifier circuit. Background technique [0002] High-speed output rectifier diodes have been used in rectifier devices of DC-DC converters. Due to its lower output voltage and higher current, the forward voltage drop of the diode can no longer be ignored. As a countermeasure against this problem, a so-called synchronous rectifier circuit system has been proposed and put into practice, which utilizes a switching device such as a FET to provide a small voltage drop in the on state. [0003] When FETs are used in the rectification device of the synchronous rectifier circuit, because the control is realized by the voltage between the gate and the source, malfunctions may occur, especially in the non-conduction (OFF) stat...

AI Technical Summary

Problems solved by technology

[0009] Therefore, it is impossible to completely prevent the rectifier device Q10 that should be turned off from entering the on state (self-conducting state).

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