| 摘要 |
PURPOSE:To omit a terminating resistance needed for the integrated circuit of a ternary pulse generating circuit used for a digital repeater, etc., by generating a ternary pulse rising rapidly by a small number of elements. CONSTITUTION:A ternary pulse generating circuit is constituted by providing input terminals 1, 2 and 4', reference voltage terminal 5, and power voltage terminal 6 in addition to transistors Tr7-Tr9, and output transistor 11 constituting a current switching circuit. A pulse corresponding to a positive-polarity output is applied from terminal 1 to the base of Tr7 of this circuit, and that corresponding to a negative-polarity output from terminal 2 to the base of Tr8; and the NOR pulse of a base-applied signal applied to Trs7 and 8 is applied to the base of Tr9 and while in-phase and out-of-phase primary windings of transformer 11 is conneced to collectors of Trs7 and 8, constant-current circuit 10 is connected to emitters of Trs7, 8 and 9 in common. Then, Trs7, 8 and 9 constituting the current switching circuit are driven complementarily to improve the rising time of a waveform outputted from output terminal 3, so that the need for the terminating resistance of an integrated circuit will be eliminated. |
