| 摘要 |
PURPOSE:To prevent thermal runaway of an ECL logical gate circuit by providing a temperature response circuit so as to decrease a control potential of a transistor (TR) applying constant voltage drive to a constant current TR being a component of an ECL logical gate circuit at a specific temperature or over. CONSTITUTION:Since no current flows to the temperature response circuit 3 through a resistor R4 from a high potential power supply Vcc of the bias circuit 2, the bias circuit 2 acts like a conventional constant voltage generating circuit to control the current flowing through the constant current TR Q4 of the ECL logical gate circuit 1 so as to keep the output amplitude constant. On the other hand, if the operating temperature rises abnormally to, e.g., 150 deg.C, the bias current drive TR Q4 is turned off by the operation of the temperature response circuit 3 and the output voltage of the bias circuit 2 is decreased. Thus, the gate current flowing to the constant current TR QG4 of the ECL logical gate circuit 1 is zero and the total current of the ECL logical gate circuit 1 is decreased.
|
