| 摘要 |
PURPOSE:To accurately follow up the response of an output signal for an input signal to a fast switching operation by constituting the title circuit of an NPN type transistor small in capacity being attached on a base area such as between a base and a collector and between the base and the ground. CONSTITUTION:When a signal of L is inputted to an input terminal 12 and and a signal of H to an input terminal 13, the emitter current I1 of a transistor(TR)1 is decreased, and the emitter current I2 of a TR2 is increased. The current I1 goes to the collector current I2 of a TR4 by the current mirrors of the TRs 3 and 4. Then, a current difference I2-I1 goes to the base current of a TRs, thereby, the TR5 is turned ON. Adversely, when the signal of M is inputted to the terminal 12 and the signal of L to the terminal 13, the I1 of the TR1 is increased, and the I2 of the TR2 is decreased. Then, the base current (I2-I2) of the TR5 disappears, thereby, the TR5 is turned OFF. By selecting values in which no saturation of TRs 6 and 7 are generated as the current values of the constant current source of a differential circuit consisting of the TRs 6 and 7 and resistors 8 and 9 by the switching operation, and eliminating a saturation area to decelerate the operating speed of the TR, it is possible to follow up the fast switching operation. |
