Recent questions in Digital Electronics

Two flip-flops are interconnected as shown in the figure. The present state of the flip flops are: $A=1, B=1$. The input x is given as $1,0,1$ in the next three clock cyc...

The address lines $A_9 \dots A_2$ of a 10 bit, 1.023 V full-scale digital to analog converter $(DAC)$ is connected to the data lines $D_7$ to $D_0$ of an 8-bit microproce...

A $6\frac{1}{2}$ digit timer-counter is set in the ‘time period’ mode of operation and the range is set as ‘ns’. For an input signal, the timer-counter displays $1000000$...

Given $f(A,B,C,D)=\sum m(0,1,2,6,8,9,10,11)+\sum d(3,7,14,15)$ is a Boolean function, where m represents min-terms and d represents don’t-cares. The minimal sum of produc...

The boolean expression for the shaded regions as shown in the figure is _________$(A+B)\bullet (\overline{A}+\overline{B})$$(A+\overline{B})\bullet (\overline{A}+B)$$(\ov...

The boolean operation performed by the following circuit at the output O is _______$O=S_1\oplus S_0$$O=S_1\bullet \overline{S_0}$$O=S_1+S_0$$O=S_0\bullet \overline{S_1}$

The two inputs $A$ and $B$ are connected to an $R-S$ latch via two $AND$ gates as shown in the figure. If $A=1$ and $B=0$, the output $Q\overline{Q}$ is$00$$10$$01$$11$

An $8$-bit microcontroller with $16$ address lines has $3$ fixed interrupts i.e., $\text{Int 1}$, $\text{Int 2}$ and $\text{Int 3}$ with corresponding interrupt vector a...

$\text{A}$ and $\text{B}$ are the logical inputs and $\text{X}$ is the logical output shown in the figure. The output $\text{X}$ is related to $\text{A}$ and $\text{B}$ ...

The circuit shown in the figure below uses ideal positive edge-triggered synchronous J-K flip flops with outputs X and Y. If the initial state of the output is X =0 and Y...

An 8-bit weighted resistor digital-to-analog converter(DAC) has the smallest resistance of 500 $\Omega$. The largest resistance has a value $\_\_\_\_$ k$\Omega$.

The total number of Boolean functions with distinct truth-tables that can be defined over 3 Boolean variables is $\_\_\_\_$.

The figure below shows the i $^{th}$ full-adder block of a binary adder circuit. C${_i}$ is the input carry and C${_i}{_+}{_1}$ is the output carry of the circuit. Assume...

$X=X_1X_0 \;and\;Y=Y_1Y_0$ are 2-bit binary numbers. The Boolean function $S$ that satisfies the condition “If $X>Y$, then $S=1”$, in its minimized form, is$X_1Y_1+X_0Y_0...

In the circuit below, the light dependent resistor $(LDR)$ receives light from the $LED$. The $LDR$ has resistances of $5\;k\Omega$ and $500\;\Omega$ under dark and illum...

The frequency response of a digital filter H($\omega$) has the following characteristicsPassband: 0.95$\le$|H($\omega$|$\le$1.05 for 0$\le$$\omega$$\le$0.3$\pi$ andStopba...

In a microprocessor with a 16 bit address bus, the most significant address lines A15 to A12 are used to select a 4096 word memory unit, while lines A0 to A11 are used to...

The Boolean expression $XY+(X’+Y’)Z$ is equivalent to$XYZ’+X’Y’Z$$X’Y’Z’+XYZ$$(X+Z)(Y+Z)$$(X’+Z)(Y’+Z)$

In the digital circuit given below, $F$ is$XY+Y\overline{Z}$$XY+\overline{Y}Z$$\overline{X}\overline{Y}+Y\overline{Z}$$XZ+\overline{Y}$

A $4$ to $1$ multiplexer to realize a Boolean function $F(X, Y, Z)$ is shown in the figure below. The inputs $Y$ and $Z$ are connected to the selectors of the $MUX$ ($Y$ ...

A synchronous counter using two J-K flip flops that goes through the sequence of states: $Q_1Q_2=00\rightarrow10\rightarrow01\rightarrow11\rightarrow00 \dots$ is required...

A $1$ Kbyte memory module has to be interfaced with an $8$-bit microprocessor that has $16$ address lines.The address lines $A_0$ to $A_9$ of the processor are connected ...

The comparators (output=$’1’$, when input $\underline{>}$ and output=$’0’$, when input$<0$), exclusive-OR gate and the unity gain low-pass filter given in the circuit are...

Consider the logic circuit with input signal $\text{TEST}$ shown in the figure. All gates in the figure shown have identical non-zero delay. The signal $\text{TEST}$ whic...

The logic evaluated by the circuit at the output is $X\overline{Y}+Y\overline{X}$$(\overline{X+Y})XY$$\overline{XY}+XY$$\overline{X}Y+X\overline{Y}+X+Y$

In the circuit shown, the switch is momentarily closed and then opened. Assuming the logic gates to have equal non-zero delay, at steady state, the logic states of X and ...

An $ADC$ is interfaced with a microprocessor as shown in the figure. All signals have been indicated with typical notations. Acquisition of one new sample of the analog i...

For the circuit shown in the figure, the rising edge triggered D-flip flop with asynchronous reset has a clock frequency of $\text{1 Hz}$. The $\text{NMOS}$ transistor ha...

The figure is a logic circuit with inputs $A$ and $B$ and output $Y.V_{95}=+5\;V$. The circuit is of type$NOR$$AND$$OR$$NAND$

An $N-$bit, $ADC$ has an analog reference voltage $V$. Assuming zero mean and uniform distribution of the quantization error, the quantization noise power will be:$\frac{...

A microprocessor accepts external interrupts (Ext INT) through a Programmable Interrupt Controller as shown in the figure. Assuming vectored interrupt, a correct sequence...

The circuit in the figure represents a counter-based unipolar $ADC$. when $SOC$ is asserted the counter is reset and clock is enabled so that the counter counts up and th...

In the circuit shown below, $\text{Q}_1$ has negligible collector-to-emitter saturation voltage and the diode drops negligible voltage across it under forward bias. If $\...

The digital circuit shown below uses two negative edge-triggered D-flip-flops. Assuming initial condition of $Q1$ and $Q0$ as zero, the output $Q1Q0$ of this circuit is $...

A bulb in a staircase has two switches, one switch being at the ground floor and the other one at the first floor. The bulb can be turned $ON$ and also can be turned $OFF...

The state transition diagram for the logic circuit shown is

Consider the given circuit.In the circuit, the race rounddoes not occuroccurs when $\text{CLK}=0$occurs when $\text{CLK}=1$ and $\text{A=B=1}$occurs when $\text{CLK=1}$ a...

In the sum of products function $f(X,\;Y,\;Z)=\sum(2,\;3,\;4,\;5),$ the prime implicants are $\overline{X}Y,\;X\overline{Y}$$\overline{X}Y,\;X\overline{Y}\;\overline{Z},\...

The output $\text{Y}$ of a $2$-bit comparator is logic $1$ whenever the $2$-bit input $\text{A}$ is greater than the $2$- bit input $\text{B}$. The number of combinations...

The sampling rate for Compact Discs $(CDs)$ is $44,000\; samples/s$. If the samples are quantized to $256$ levels and binary coded, the corresponding bit rate (in bits pe...