CMOS Sigma Delta Modulator AD7720

　　This device is a 7th order sigma-delta modulator that converts the analog input signal into a high speed 1-bit data stream. The part operates from a +5 V supply and accepts a differential input range of 0 V to +2.5 V or ±1.25 V centered about a commonmode bias. The analog input is continuously sampled by the analog modulator， 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 reconstructed with an appropriate digital filter. The part provides an accurate on-chip 2.5 V reference. A reference input/output function is provided to allow either the internal reference or an external system reference to be used as the reference source for the part. The device is offered in a 28-lead TSSOP package and designed to operate from –40°C to +85°C.