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cjm181
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Homework Statement
.[/B]The full range input of a12-bit, successive-approximation type ADC is 1 volt. Determine:
- a) the maximum input change required to give a one bit change in output of the ADC
- b) The number of approximations made to complete the conversion of an input signal of 0.8125 V and the final binary result of the conversion process.
Homework Equations
The Attempt at a Solution
a) Vres = Vref / ((2^n)-1) = 1 / ((2^12)-1) = 2.442x10^-4
b) Going to type this backwards!
0 to 1v input range, output range 0 to 4095 hex for a 12 bit system. So, to find the hex value for an input of 0.8125v:
4095 * 0.8125 = 3327.188 or 3327. So convert this to binary gives an output of 11 00 11 11 11 11.
So the number of approximations made! the bit i am struggling with!
As 3327 was not reached until all 12 bits had run thru the system, does this mean 12 approximations were made?
Say the hex input was 2048 (10 00 00 00 00 00), would the number of approximations be 1?
Thanks
Craig