pankaj jha
Full Member level 3
Hello everyone !!!!
My question is regarding the method to process the digital output of sigma delta ADCs.
For example:
Lets take the example of 3-bit flash ADC. Assume that it outputs a binary 010 for an analog input of 2V. Another flash ADC of the same kind outputs a binary 011 for an analog input of 3V. Now if we wish to find the product of the two analog inputs, we can perform the binary multiplication of 010 and 011 to obtain a binary 110 as the result. Binary 110 is equivalent to analog 6V, which is exactly what we expected( 2V*3V=6V). Hence the binary result is a direct representation of the analog output.
Now, lets take the case of sigma delta ADC. Assume that the following is the output of this ADC.
Result for 20 samples
Input volts Sequence of output bits
0.2 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1
Now if we try to find the product of analog 0.2V with itself, i.e. 0.2*0.2. If we try to find the normal binary product of the the output provided by the sigma delta ADC, we see that the binary result does not directly represent the expected 0.04 analog voltage.
Hence, can anyone tell me how is the processing done in the case of delta sigma ADC, and how is the result obtained post processing is analysed.
---------- Post added at 05:50 ---------- Previous post was at 05:48 ----------
digital processing of digital output of a sigma delta ADC
Hello everyone !!!!
My question is regarding the method to process the digital output of sigma delta ADCs.
For example:
Lets take the example of 3-bit flash ADC. Assume that it outputs a binary 010 for an analog input of 2V. Another flash ADC of the same kind outputs a binary 011 for an analog input of 3V. Now if we wish to find the product of the two analog inputs, we can perform the binary multiplication of 010 and 011 to obtain a binary 110 as the result. Binary 110 is equivalent to analog 6V, which is exactly what we expected( 2V*3V=6V). Hence the binary result is a direct representation of the analog output.
Now, lets take the case of sigma delta ADC. Assume that the following is the output of this ADC.
Result for 20 samples
Input volts------->Sequence of output bits
0.2V--------------> 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1
Now if we try to find the product of analog 0.2V with itself, i.e. 0.2*0.2. If we try to find the normal binary product of the the output provided by the sigma delta ADC, we see that the binary result does not directly represent the expected 0.04 analog voltage.
Hence, can anyone tell me how is the processing done in the case of delta sigma ADC, and how is the result obtained post processing is analysed.
My question is regarding the method to process the digital output of sigma delta ADCs.
For example:
Lets take the example of 3-bit flash ADC. Assume that it outputs a binary 010 for an analog input of 2V. Another flash ADC of the same kind outputs a binary 011 for an analog input of 3V. Now if we wish to find the product of the two analog inputs, we can perform the binary multiplication of 010 and 011 to obtain a binary 110 as the result. Binary 110 is equivalent to analog 6V, which is exactly what we expected( 2V*3V=6V). Hence the binary result is a direct representation of the analog output.
Now, lets take the case of sigma delta ADC. Assume that the following is the output of this ADC.
Result for 20 samples
Input volts Sequence of output bits
0.2 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1
Now if we try to find the product of analog 0.2V with itself, i.e. 0.2*0.2. If we try to find the normal binary product of the the output provided by the sigma delta ADC, we see that the binary result does not directly represent the expected 0.04 analog voltage.
Hence, can anyone tell me how is the processing done in the case of delta sigma ADC, and how is the result obtained post processing is analysed.
---------- Post added at 05:50 ---------- Previous post was at 05:48 ----------
digital processing of digital output of a sigma delta ADC
Hello everyone !!!!
My question is regarding the method to process the digital output of sigma delta ADCs.
For example:
Lets take the example of 3-bit flash ADC. Assume that it outputs a binary 010 for an analog input of 2V. Another flash ADC of the same kind outputs a binary 011 for an analog input of 3V. Now if we wish to find the product of the two analog inputs, we can perform the binary multiplication of 010 and 011 to obtain a binary 110 as the result. Binary 110 is equivalent to analog 6V, which is exactly what we expected( 2V*3V=6V). Hence the binary result is a direct representation of the analog output.
Now, lets take the case of sigma delta ADC. Assume that the following is the output of this ADC.
Result for 20 samples
Input volts------->Sequence of output bits
0.2V--------------> 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1 1 0 1 0 1
Now if we try to find the product of analog 0.2V with itself, i.e. 0.2*0.2. If we try to find the normal binary product of the the output provided by the sigma delta ADC, we see that the binary result does not directly represent the expected 0.04 analog voltage.
Hence, can anyone tell me how is the processing done in the case of delta sigma ADC, and how is the result obtained post processing is analysed.