Q. A Schmitt trigger has VT+ = 2.0 V and VT– = 1.2 V. What is the hysteresis voltage of the Schmitt trigger?
✅ Correct Answer: (C)
0.8 volt
Digital Electronics MCQs and Notes
Q. Why would a delay gate be needed for a digital circuit?
✅ Correct Answer: (D)
to provide for setup times and hold times
Q. The ________ circuit overcomes the problem of switching caused by jitter on the inputs.
✅ Correct Answer: (D)
schmitt trigger
Q. How many flip-flops are required to produce a divide-by-128 device?
✅ Correct Answer: (D)
7
Q. How is a J-K flip-flop made to toggle?
✅ Correct Answer: (D)
j = 1, k = 1
Q. Propagation delay time, tPLH, is measured from the ________.
✅ Correct Answer: (A)
triggering edge of the clock pulse to the low-to-high transition of the output
Q. Which statement BEST describes the operation of a negative-edge-triggered D flip-flop?
✅ Correct Answer: (A)
the logic level at the d input is transferred to q on ngt of clk.
Q. Determine the output frequency for a frequency division circuit that contains 12 flip-flops with an input clock frequency of 20.48 MHz.
✅ Correct Answer: (B)
5 khz
Q. Settling time is normally defined as the time it takes a DAC to settle within ________.
✅ Correct Answer: (C)
1/2 lsb of its final value when a change occurs in the input code