| 摘要 |
PURPOSE:To perform switching drive at a high speed with low power consumption by controlling the voltage of a Darlington-connected field-effect transistor (FET). CONSTITUTION:The base of a bipolar transistor (TR) 5 is driven by the FET 5 which is Darlington-connected as a voltage control element to a bipolar TR 1 to be driven. Namely, when a high-level voltage is impressed from a control circuit 4 to the gate of the MOSTR 5, the MOSTR 5 turns on and its drain current is supplied to the base of the bipolar TR 1. Then, the bipolar TR 1 turns on according to the drain current. When the output voltage of the control circuit 4 is lowered to zero, the MOSTR 6 turns off and a pnp TR 6 turns off at the same time. The base forward current to the bipolar TR 1 is therefore cut off and a little remaining carriers in the bipolar TR 1 flow to the earth potential as a base backward current through the pnp TR 6. |
