| 摘要 |
PURPOSE:To measure the gate leak current and the appropriate maximum applying voltage for the subject transistor by a method wherein a prescribed voltage is applied in between a gate and a source through the intermediary of a resistor and the amount of variation of a drain current for the voltage variation between the drain and the source is calculated. CONSTITUTION:A resistor R and a source of variable current VGS are connected between the gate and the source of a junction type FETQ, the source of variable current VGS is connected between the drain and the source through the intermediary of an ammeter and is used as a measuring current. In this measuring current, when there exists a gate leak current IGSX, the terminal voltage of the gate increase to the extent of IGSX.R from the applied voltage. Therefore, the variation of the drain current ID for the VDS, which is the parametered VGS, is forming the characteristics as shown by the solid lines and it differs from the tendency in the ordinary case of R=0 as shown by the dotted lines. Through these procedures, the variation characteristic of IGSX for the variation of VDS can be calculated from the measured value of ID when R is added. Also, the difference of ID between the solid lines and the dotted lines is measured and an appropriate maximum applying voltage can be established using the voltage obtained when the difference value becomes constant. |
