| 摘要 |
PURPOSE:To prevent the saturation of a bipolar transistor (TR) by providing a supply source of a base current independently of a supply source of a collector current in at least one bipolar TR. CONSTITUTION:The bipolar TR Q1A is to charge up an output terminal O and a circuit C1 controls the base current of the TR Q1A. The circuit C2 is to discharge the output terminal O. The off-level is the subtraction of a base-emitter forward voltage VBE from a base potential B of the TR Q1A. Thus, in order to obtain a desired off-level, the circuit C1 and the base current supply source are designed to increase the potential of the base B more than the desired off-level by a value VBE at the charging of the output terminal O. |
