Lab1-Digital

A 555 timer IC can be used for the following

• Amplify a small signal into a larger signal for better visualization

• Calculate the signal duration

• generate a square wave with pre-determined period and duty cycle

• generate a counter circuit

The Astable 555 timer duty cycle in the circuit below can be determined by

• R1 only

• R1 and R2 only

• R1, R2, C1 and C2

• R1, R2 and C1 only

Calculate the R2 resistor value of the following astable 555 timer to generate a clock with period of 1 second and duty cycle of 50% with R1=1kΩ and C1=100uF, where the frequency f= 1.44/((R1+2R2)C)

• R2=5kΩ

• R2=10kΩ

• R2=6.7kΩ

• R2=7.9kΩ

Mode-6 counter is

• A counter circuit that can count 1-6 in binary

• A counter circuit that can count 1-16 in binary

• A counter circuit that can count 0-15 in binary

• A counter circuit that can count 0-5 in binary

For a counter circuit using 74HC93 IC, which of the following method to modify the circuit into a mod-6 counter? (reset when output 0110b, MSB to LSB QD, QC, QB, QA)

• Connect MR1 to QB and MR2 to QD

• Connect MR1 to QB and MR2 to QC

• Connect MR1 to QA and MR2 to QB

• Connect MR1 and MR2 to 5V Vcc

Based on the given truth table below, the output D is equal to:

• D=0

• D=QdQcQbQa

• D=1

• D=Qd+Qc+Qb+Qa

Based on the given truth table below, the output C can be filled into a K-map and simplified as:

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Based on the given truth table below, the output B can be filled into a K-map and simplified as:

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The following simplified equation can be applied into a logic gates circuit as:

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Which of the following is the correct statement on 7-segment display?

• Common anode 7-segment display has positive common pin and must be connected to Vcc, The segments can be turned on by giving logic 0 to their pins

• Common cathode 7-segment display has negative common pin and must be connected to Vcc, The segments can be turned on by giving logic 0 to their pins

• Common cathode 7-segment display has positive common pin and must be connected to Vcc, The segments can be turned on by giving logic 0 to their pins

• Common anode 7-segment display has positive common pin and must be connected to Vcc, The segments can be turned on by giving logic 1 to their pins