Question

In digital circuits, why are normal transistors less preferred compared to Schottkey transistors?

(a) Lower propagation delay
(b) Higher propagation delay
(c) Lower power dissipation
(d) Higher power dissipation

Answer 1

Schottky transistors are preferred in digital circuits over normal transistors mainly because of their lower propagation delay which allows for faster switching, essential for high-speed digital applications.

Step-by-step explanation:

In digital circuits, Schottky transistors are often preferred over normal transistors due to their lower propagation delay. Propagation delay is the time it takes for a signal to pass through a device, usually measured from when the input to a transistor changes until the output reaches a certain percentage of its final value. The lower the delay, the faster the circuit can operate.

Schottky transistors have a design that incorporates a Schottky barrier between a semiconductor and a metal contact. This barrier reduces the capacitance of the transistor's junction and therefore decreases the time it takes for the transistor to turn on and off. As a result, Schottky transistors can switch faster than normal transistors, which is critical in high-speed digital applications where rapid switching is essential.

Furthermore, digital signals in circuits, as represented in binary code, require quick transitions between states to accurately represent ones and zeroes. As transistors serve as the on-off switches for these signals, having a lower propagation delay, as seen in Schottky transistors, improves the overall performance of digital electronic devices.