AD7724,pdf datasheet (Modulato

This device consists of two seventh order sigma-delta modulators.

Each modulator converts its analog input signal into a high

speed 1-bit data stream. The part operates from a 5 V power

supply and accepts a differenTIal input range of 0 V to +2.5 V or

±1.25 V centered about a common-mode bias. The analog inputs

are conTInuously sampled by the analog modulators, eliminaTIng

the need for external sample-and-hold circuitry. The input

informaTIon is contained in the output stream as a density of

ones. The original information can be digitally reconstructed

with an appropriate digital filter.