| 摘要 |
PURPOSE:To enable effective prevention of electrostatic breakdown in an output transistor, by connecting a protective diode, toward a power voltage terminal and in the forward direction, between an emitter terminal of an output transistor in a bipolar integrated circuit and the power voltage terminal on the plus side of this circuit. CONSTITUTION:when an output circuit 2 instead of an input circuit 3 is connected to an aimed input/output terminal 1 so that it is used as an output pin, aluminium wiring connection is performed on a position shown in alternate-long- and-one-short-dash lines b1-b3. Thus, a diode d2 is connected toward an earth point and in the forward direction between an emitter terminal of an emitter follower transistor (output transistor) Qe connected to an output terminal 1' in an ECL type output circuit 2 and a power voltage terminal such as an earth point. When a plus abnormal voltage is applied, a by-pass current is made to flow toward the earth point via the diode d2. Consequently, breakdown of an emitter. collector junction in the output transistor Qe can be prevented. |
