JPH0444735U

JPH0444735U -

Info

Publication number: JPH0444735U
Application number: JP8763990U
Authority: JP
Priority date: 1990-08-22
Filing date: 1990-08-22
Publication date: 1992-04-16

Description

[Brief explanation of the drawing]

第１図は請求項１に関わる考案の一実施例の構
成図、第２図は第１図例における電位変化波形図
、第３図は請求項２に関わる考案の一実施例のブ
ロツク図、第４図は第３図例の具体的回路図、第
５図は第３図例における入力容量電荷量の変化波
形図、第６図は請求項２に関わる考案の他の実施
例のブロツク図、第７図は第６図例の具体的回路
図、第８図は請求項２に関わる考案のさらに他の
実施例のブロツク図、第９図は第８図例の具体的
回路図、第１０図はパワーＭＯＳＦＥＴの寄生
容量説明図、第１１図はパワーＭＯＳＦＥＴの
ゲート電極入力端交流等価回路図、第１２図およ
び第１３図は従来例における入力容量電荷量の変
化波形図である。１……ゲート電極オーバードライブ用電源部、
２……パワーＭＯＳＦＥＴオン状態保持用電源
部、３，３ａ……ゲート電極印加電圧選択部、４
……ゲート電極電位レベル検知部、５，５ａ……
パワーＭＯＳＦＥＴ駆動回路部、６……パワー
ＭＯＳＦＥＴ、７……負荷電流検知部、８……
ＶＤＳ電圧検出部。 FIG. 1 is a block diagram of an embodiment of the invention related to claim 1, FIG. 2 is a potential change waveform diagram in the example of FIG. 1, and FIG. 3 is a block diagram of an embodiment of the invention related to claim 2. 4 is a specific circuit diagram of the example in FIG. 3, FIG. 5 is a waveform diagram of changes in input capacitance charge in the example in FIG. 3, and FIG. 6 is a block diagram of another embodiment of the invention related to claim 2. , FIG. 7 is a specific circuit diagram of the example shown in FIG. 6, FIG. 8 is a block diagram of still another embodiment of the invention related to claim 2, FIG. 9 is a specific circuit diagram of the example shown in FIG. Fig. 10 is an explanatory diagram of the parasitic capacitance of the power MOS FET, Fig. 11 is an AC equivalent circuit diagram of the gate electrode input terminal of the power MOS FET, and Figs. 12 and 13 are change waveform diagrams of the input capacitance charge amount in the conventional example. . 1...Power supply section for gate electrode overdrive,
2...Power supply unit for maintaining the power MOS FET on state, 3, 3a...Gate electrode applied voltage selection unit, 4
...Gate electrode potential level detection section, 5, 5a...
Power MOS FET drive circuit section, 6... Power MOS FET, 7... Load current detection section, 8...
VDS voltage detection section.

Claims

[Claims for Utility Model Registration] (1) A Zener diode connected between the gate electrode and source electrode of a MOS field effect transistor, the Zener voltage of which is close to the threshold voltage of the MOS field effect transistor; A voltage higher than the threshold voltage is applied to the M in accordance with the MOS type field effect transistor drive command signal.
A driving device for a MOS type field effect transistor, comprising: means for supplying the gate electrode to the gate electrode of the OS type field effect transistor. (2) detection means for detecting whether the MOS field effect transistor is in the on state or the off state; and generating a first voltage near the threshold voltage necessary for the MOS field effect transistor to be in the on state. a first voltage source that generates a second voltage higher than the first voltage; and a second voltage source that generates a second voltage higher than the first voltage;
When the OS type field effect transistor is in the off state, the second voltage from the second voltage source is selected, and when the MOS type field effect transistor is in the on state, the first voltage is selected. voltage selection means for selecting a first voltage from the source; and voltage selection means for selecting a first voltage from the MOS field effect transistor drive command signal, and applying the first voltage or second voltage selected by the voltage selection means to the MOS field effect transistor drive command signal. A driving device for a MOS field effect transistor, comprising: driving means for supplying power to an effect transistor and driving the MOS field effect transistor.