I am studying for ADC Pi, for my Presentation. it uses MCP3424 Chips that uses Delta Sigma ADC.
I know how Successive Approximation ADC Works (on paper).
But how Delta-Sigma ADC Performs the calculation from Analog to Digital. For instance,
If the input Analog voltage is 5volts and the reference voltage is 2.048volts. And I programmed the ADC Pi for 17-bits (3.75 Samples per Seconds)
How these input 5volts will be encoded into digitized form for this very ADC (Delta Sigma / ADC Pi) ????
for instance, let's take an example of Successive approximation ADC , here is what it does,
If there is a 3-bit ADC then and the Reference Voltage is 2volts, then,
2^3 = 8-bits
Now 2volts will be divided in 8 levels.
8/2 = 0.25volts (each level will represent 0.25 volts
000 = 0 -> 0.25 volts 001 = 0.25 -> 0.50 010 = 0.50 -> 0.75 011 = 0.75 -> 1.00 100 = 1.00 -> 1.25 101 = 1.25 -> 1.50 110 = 1.50 -> 1.75 111 = 1.75 -> 2.00
How would i perform such calculation for ADC Pi (Delta Sigma) which is programmed for 17-bit ?
All that i could think of is,
The bit size is
Reference voltage is
2^17 = 131072
Does that mean there will be
131072 levels ?
2.048/131072 = 0.000007812volts Does that mean each level will represent,
0.0000156 volts ?
Now if the input voltage is
3.3volts the digital output will be,
0.0000156 * X = 3.3volts X = 211538D X = 110011101001010010B
Is that right ?
I have tried Googling a lot but couldn't find any basic example for Delta Sigma ADC which is why i eventually posted it here.