DIGITAL SYSTEM
Example 2:
An 8-bit successive approximation ADC is presented with an analog value of 143. Use the successive
approximation method to determine the binary value of its analog input.
1000 0000 128 < 143 1
1100 0000 192 > 143 0
1010 0000 160 > 143 0
1001 0000 144 > 143 0
1000 1000 136 < 143 1
1000 1100 140 < 143 1
1000 1110 142 < 143 1
1000 1111 143 = 143 1
∴ The digital value for = 1000 1111
1. Compare the maximum conversion times of a 9-bit digital ramp ADC and a 9-bit successive
approximation ADC if both utilize a 650kHz clock frequency.
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2. A 5-bit successive approximation ADC has a resolution of 27mV. Determine the digital output for an
analog input of 0.58V and show its conversion diagram.
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3. A 6-bit successive approximation ADC is used to convert the signal from a sensor. The voltage input
range is 0 – 5V.
a) Calculate the resolution of the ADC card.
b) Show the conversion process of the ADC card when the voltage input to the ADC card is 3V.
Determine the binary number as the result of the conversion.
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4. A 10-bit successive approximation ADC is presented with an analog value of 350. Use the successive
approximation method to determine the binary value of its analog input. Assuming that each test takes
a single clock cycle, determine the maximum conversion time for the ADC if it is clocked at 3.2
MHz.
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REFERENCES
Tocci, R. J., Widmer, N. S., & Moss, G. L. (2007). Digital Systems: Principles and Applications
(10th ed.). Upper Saddle River,NJ: Pearson/Prentice Hall.
Muhamad, S., & Mohammed Khalid, M. N. (2013). Digital Electronics. Kuala Lumpur: Oxford
Fajar.
Prasad, P. W. Chandana, Lau, S. H., Singh, A. K., & Suryanata, M. (2002). Digital System
Fundamentals. Malaysia: Prentice Hall.
Bartelt, T. L. M. (2002). Digital Electronics An Integrated Laboratory Approach. Upper Saddle
River, NJ: Prentice Hall.
Tokheim, R. L. (2008). Digital Electronics: Principles & Applications (7th ed.). Boston:
McGraw-Hill Higher Education.
Floyd, T. L., & Buchla, D. M. (2005). The Science of Electronics Digital. Upper Saddle River,
NJ: Pearson/Prentice Hall.
Kleitz, W. (2008). Digital Electronics: A Practical Approach (8th ed.). Upper Saddle River, NJ:
Pearson/Prentice Hall.
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