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A lambda diode is an electronic circuit that combines a complementary pair of field-effect transistors into a two-terminal device that exhibits an area of differential negative resistance much like a tunnel diode. The term refers to the shape of the V/I curve of the device, which resembles the Greek letter λ ''(lambda)''. Lambda diodes work at higher voltage than tunnel diodes. Whereas a typical tunnel diode〔(1N3712 data sheet )〕 may exhibit negative differential resistance between some 70mV - 350 mV, this region occurs between about 1.5V - 6V in a lambda diode due to the higher pinch-off voltages of typical JFET devices. A lambda diode can therefore not replace a tunnel diode directly. Moreover, in a tunnel diode the current reaches a minimum of some 20% of the peak current before rising again towards higher voltages. The lambda diode current approaches zero as voltage increases, before rising quickly again at a voltage high enough to cause gate-source Zener breakdown in the FETs. It is also possible to construct a device similar to a lambda diode by combining an n-channel JFET with a PNP bipolar transistor.〔(Oscillations and Regenerative Amplification using Negative Resistance )〕 ==Applications== Like the tunnel diode, the negative resistance aspect of the lambda diode lends itself naturally to application in oscillator circuits〔(''A Dip Meter Using the Lambda Negative Resistance Circuit.'' ) Lloyd Butler, ''Amateur Radio'', January 1997.〕 and amplifiers. In addition, bistable circuits such as memory cells have been described.〔United States Patent 4376986: Double Lambda diode memory cell; http://www.wipo.int/pctdb/images4/PCT-PAGES/1983/091983/83001335/83001335.pdf〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lambda diode」の詳細全文を読む スポンサード リンク
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