| 摘要 |
<p>A logic circuit comprises OR gates 11A, 11B, 11C, connected into the inputs of an AND gate, and is capable of operating with OR gate inputs either from GaAs circuits with logic levels of -0.3v and -1.7v or ECL currents with logic levels of -0.8v and -1.6v. The AND gate comprises diodes 21 with a pull-up transistor Q1 and pull-down transistors Q2, Q3 and Q4 and forms part of a voltage-shifting network including also additional diodes 18, 19. The resulting voltages at the AND gate output are -1.7v and -3.1v (GaAs input) or -2.2v and -3.0v (ECL input). A suitable choice of amplifier (13) will yield from either set of voltages an output suitable for driving GaAs logic, or, with a source-follower output stage, an output suitable for ECL. </p> |
