pankaj jha
Full Member level 3
hello everyone!!
I am reading the book "CMOS cascade sigma delta modulators for sensors and telecom - Error analysis and practical design".
In the first chapter, while discussing about the DAC errors in ∑Δ modulators it says--
"" for a 4-bit sigma delta Modulator with 16-bit linearity, the required matching of the unit elements in the DAC should be better than 0.01% (13 bits). Unfortunately, component matching that can be achieved in present-day standard CMOS processes is in the range of 0.1% (10 bits), so that the required accuracy in the unit elements could only be obtained through the parallel connection of many (over 64) large components. ""
Can anyone elaborate on this? My question is how a matching of 0.01% corresponds to 13 bits. Is there any formula which connects the two?
I am reading the book "CMOS cascade sigma delta modulators for sensors and telecom - Error analysis and practical design".
In the first chapter, while discussing about the DAC errors in ∑Δ modulators it says--
"" for a 4-bit sigma delta Modulator with 16-bit linearity, the required matching of the unit elements in the DAC should be better than 0.01% (13 bits). Unfortunately, component matching that can be achieved in present-day standard CMOS processes is in the range of 0.1% (10 bits), so that the required accuracy in the unit elements could only be obtained through the parallel connection of many (over 64) large components. ""
Can anyone elaborate on this? My question is how a matching of 0.01% corresponds to 13 bits. Is there any formula which connects the two?