| 摘要 |
PURPOSE:To vary continuously the level shift quantity by controlling a gate voltage of a constant current field effect transistor (FET) of a level shift circuit so as to change the constant current value thereby utilizing a change in the voltage drop of a level shift diode due to a series resistor. CONSTITUTION:A resistor RGS is inserted between a gate and source of a constant current FET Q2, a control terminal CT is provided to a gate of the constant current FET Q2 so as to apply a bias voltage to the control terminal in a level shift circuit where a level shift diode D and the constant current FET Q2 as the 2nd transistor (TR) are connected to an input FET Q1 as the 1st TR in a ways of source follower. The constant current value of the constant current FET Q2 is changed by varying the bias voltage of the control terminal CT to change the voltage drop of the series resistor of the level shift diode D thereby adjusting minutely the level shift voltage.
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