Datasheet AD7720 (Analog Devices)

a
CMOS Sigma-Delta Modulator AD7720 FUNCTIONAL BLOCK DIAGRAM FEATURES 12.5 MHz Master Clock Frequency 0 V to +2.5 V or
6
1.25 V Input Range AVDD AGND DVDD DGND REF1 Single Bit Output Stream 90 dB Dynamic Range AD7720 Power Supplies: AVDD, DVDD: +5 V
6
5% 2.5V REF2 REFERENCE On-Chip 2.5 V Voltage Reference 28-Lead TSSOP VIN(+) DATA SIGMA-DELTA MODULATOR VIN(–) SCLK MZERO CLOCK XTAL1/MCLK GC CIRCUITRY XTAL2 DVAL CONTROL BIP LOGIC RESETO STBY RESET GENERAL DESCRIPTION
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 common- mode 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 refer- ence input/output function is provided to allow either the inter- nal 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. REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
which may result from its use. No license is granted by implication or
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
otherwise under any patent or patent rights of Analog Devices.
Fax: 781/326-8703 © Analog Devices, Inc., 1997