| 摘要 |
PURPOSE:To obtain a constant current source by setting between gate and source the resistance equal to VGS1/ID wherein the drain current - the value at the intersection of the characteristic curves the voltage that are obtained between gate and source when ambient temperature is changed with the voltage between drain and source kept constant are ID and VGS1 respectively. CONSTITUTION:When ambient temperature is changed with the voltage between drain and source kept constant, the characteristic curves of the drain current - the voltage between gate and source intersect each other almost at a point (ID1, VGS1) and the variation of drain current by temperature is minimum at said point. This is utilized in setting the parasitic resistance between gate and source to RS VGS1/ID1 and making a short-circuit between source and gate at a source earthing type circuit so that voltage VGS1 and current ID1 can be maintained at self-saturation type bias by said resistance RS. N-epitaxial layer 2 on a P<+>-type substrate 1 is separated by P<+>-type layer 3, an FET 100 and a resistor 200 are provided on each of thus-obtained divisions of said layer 2, and resistor layer is set to RS. Each of the ends of said resistor 200 is connected to the source 6 of said FET 100 or said separating layer 3, and said substrate 1 is used as the drain of gate N<+> layer 7 so that a constant current source can be obtained. |
