| 摘要 |
PURPOSE:To shorten the accumulation time of a switching transistor even in a fine-current region and also to prevent its malfunction by providing a discharge passage of a transistor and resistance betweem the base and emitter of the switching transistor. CONSTITUTION:Once the base current of switching transistor 1 is cut off, charge accumlated in the base-emitter junction of transistor 1 is discharged by way of resistance 5 and the base of transistor 3. As a result, transistor 3 turns ON to flow a collector current, equivalent to a current obtained by multiplying a base current by a current amplification factor, as a discharge current. The sum of this discharge current flowing momentarily is between tens pice to several nano A. The accumulated charge is therefore discharged without being limited by resistance 4 and transistor 1 can immediately be turned OFF. In this way, a high-speed switching circuit can be obtained which has its accumulation time shortened even in a fine-current region and is hard to malfunction. |
