| 摘要 |
PURPOSE:To preclude the increase in kinds of power supplies for the titled circuit and to reduce the power consumption by using a photocoupling element for the level conversion between an ECL system circuit and a TTL system circuit. CONSTITUTION:A TTL element 10 in the TTL system circuit 1 drives an ECL element 20 in the ECL system circuit 2, the isolation of the power supply between the circuits is ensured and the electric level conversion is applied. The ECL element 22 drives a photodiode 111 of the photocoupler 11 in the circuit 1 by using a-5.2V power supply in the circuit 2. A resistor RC decides the forward current of the photo diode 111. A diode D0 is a reverse votlage preventing protection circuit applied to the photo diode 111 of the photocoupler 11. The photo transistor 112 of the element 11 drives the TTL element 12 of the next stage and a resistor RD decides the collector current. As a result, the ECL element 22 drives the TTL element 12 to apply electric level conversion between the circuits.
|
