摘要:
A transistor-transistor logic circuit comprises an input means (10) for receiving an input logic signal (IN), a phase-splitting transistor (13) having its base connected to the input means (10), an output transistor (16) having its base connected to the emitter of the phase-splitting transistor (13), wherein the output transistor (16) supplies an output logic signal responsive to the input logic signal from its collector, and a capacitive element (19) having one terminal connected to the collector of the phase-splitting transistor (13) and another terminal maintained at a predetermined potential. The turn-on-time of the output transistor (16) is shortened by the capacitive element (19).
摘要:
Disclosed is a schmitt trigger circuit having an input-voltage hysteresis characteristicfor reducing noise sensitivity and preventing oscillation, comprising in its input stage a multi-emitter transistor (T 11 ) and in its output stage a second transistor (T 2 ). The multi-emitter transistor comprises a first emitter (E 1 ) and a second emitter (E 2 ). The first emitter is associated with a switching operation in response to the input voltage (Vin) applied to the base of the multi-emitter transistor. The second emitter is associated with the operation of drawing charges from the base of the second transistor (Tz) through the base of the multi-emitter transistor (T 11 ) to the ground. By using the multi-emitter transistor, the input current (I 1L ) does not greatly increase as the input voltage (Vin) falls.