| 摘要 |
<p>In an ECL circuit comprising a differential type switching circuit (12) having first and second output terminals, a first transistor (a pull-up transistor Q7) connected to a first power source (V1), a second transistor (a pull-down transistor Q5) transistor connected to a second power source (V2), and a capacitor (Cc) connected between the second output terminal of the switching circuit and the base of the second transistor, the ECL circuit further comprises a constant current source (IBIAS) connected between the first power source and the base of the second transistor, and an impedance (2) connected between the base of the second transistor and the second power source. In the above ECL circuit, the base of the second transistor is biased by means of a circuit constituted by the constant current source and the impedance and the static current flowing in the second transistor can be stably maintained by using a constant current source which can be easily obtained in the prior art as the above constant current source. Further, since the base potential of the second transistor can be determined by the second power source potential of the constant current source, the power consumption can be reduced by adequately setting the second power source potential. In addition, since the base impedance of the second transistor can be set to be higher than the base impedance of the transistor Q5 in the conventional circuit shown in Fig. 1, charges injected into the base of the second transistor via the capacitor may effectively function, causing the driving ability of the second transistor to be enhanced. <IMAGE></p> |
