
It provides "Vcc" supply during the "ON" state. This circuit provides path to the GND in "OFF" state. It combines both line driver circuit and open collector transistor circuits. The figure-3 depicts push pull transistor configuration.

It offers slow switching speed due to relatively long time constant. ➨It uses pull up resistor in KOhm range and hence Vcc) output as required for some applications. ➨The circuit can provide only one output state i.e. To interface different logic families having different voltage/current requirements. ➨Open collector configuration can provide various voltages for "HIGH" output. Open collector gates offer higher current ratings. ➨Standard TTL gates with totem pole output circuit can provide 0.4mA for "HIGH" current output andġ.6 mA for "LOW" current. Hence AND gate circuit can be made by connection of its outputs. This results into logical ANDing of the output. ➨The outputs can be tied directly together. In "OFF" condition, open collector output will float. In "ON" condition, open collector configuration provides path to the GND (Ground). The figure-2 depicts open collector transistor sinking output configuration.

➨The circuit output floats in "OFF" state. ➨It can be used to directly drive the LEDs. Hence it requires sinking input for its proper operation. In "OFF" condition, the circuit output floats. In "ON" condition, the circuit provides "Vcc" at the output. The figure-1 depicts line driver sourcing output circuit. This page compares Line Driver vs Open Collector vs Push Pull transistor configurations and mentionsĭifference between line driver, open collector transistor and push pull transistor with respect to their Difference between Line Driver Open Collector Push Pull transistor Configurations
