  In this paper we prove optimality of a certain class of Analog to Digital
Converters (ADCs), which can be viewed as generalized Delta-Sigma Modulators
(DSMs), with respect to a performance measure that can be characterized as the
worst-case average intensity of the signal representation error. An analytic
expression for the ADC performance is given. Furthermore, our result proves
separation of quantization and control for this class of ADCs subject to some
technical conditions.
