| 摘要 |
PURPOSE:To prevent the breakdown of a pull-down resistance while increasing a switching speed, by providing a pull-down resistance between an input terminal and a prescribed power source terminal which is held lower than a logical low level and higher than a negative power voltage. CONSTITUTION:The collectors of input transistors Q1 and Q2 are connected in common, transistor Q3 connected in differential form to transistors Q1 and Q2 and transistors Q1 and Q2 are connected in common at emitters, and constant current circuit I0 is connected between this connection point and negative power voltage -VEE, constituting a logic block. Then, an emitter follower output circuit is composed of transistors Q4 and Q5 supplied with the output of the logic block and negative resistance R1 and R2 provided between respective emitters and voltage terminal (-VTT), and pull-down resistances RP1 and RP2 are provided between voltage terminal (-VTT) and input terminals A and B while voltage -VTT is set lower than the logical low level. |
