Does not exist and will not exist as such a beasty is physically
nonsense. Pray do the exercise: take a 2V full scale level, calculate
the equivalent voltage for the LSB, and compare this to the thermal
noise at room temperature of, oh, a 10 Ohms resistor ...
Additionally, the motivation to use delta-sigma converters is the possibility to achieve high signal resolution by the use of low-resolution/fast-sampling converters.
