Datasheet AD7723 (Analog Devices)

16-Bit, 1.2 MSPS CMOS, Sigma-Delta ADC AD7723 FEATURES FUNCTIONAL BLOCK DIAGRAM 16-bit Σ-∆ ADC 2.5V REF2 1.2 MSPS output word rate AVDD AD7723 REFERENCE REF1 AGND 32×/16× oversampling ratio Low-pass and band-pass digital filter VIN(+) FIR DV MODULATOR DD VIN(–) FILTER DGND Linear phase On-chip 2.5 V voltage reference UNI XTAL_OFF XTAL Standby mode XTAL HALF_PWR CLOCK CLKIN STBY Flexible parallel or serial interface MODE 1 DGND/DB15 Crystal oscillator MODE 2 DGND/DB14 Single 5 V supply SYNC SCR/DB13 DV SLDR/DB12 DD/ CS CFMT/RD CONTROL SLP/DB11 LOGIC DGND/DRDY TSI/DB10 GENERAL DESCRIPTION DGND/DB0 FSO/DB9
The AD7723 is a complete 16-bit, sigma-delta ADC. The part 001 operates from a 5 V supply. The analog input is continuously
DGND/ DGND/ DGND/ DOE/ SFMT/ FSI/ SCO/ SDO/ DB1 DB2 DB3 DB4 DB5 DB6 DB7 DB8
01186- sampled, eliminating the need for an external sample-and-hold. The modulator output is processed by a finite impulse response Figure 1. (FIR) digital filter. The on-chip filtering combined with a high The part provides an on-chip 2.5 V reference. Alternatively, an oversampling ratio reduces the external antialias requirements external reference can be used. to first order in most cases. The digital filter frequency response can be programmed to be either low-pass or band-pass. A power-down mode reduces the idle power consumption to 200 µW. The AD7723 provides 16-bit performance for input bandwidths up to 460 kHz at an output word rate up to 1.2 MHz. The The AD7723 is available in a 44-lead MQFP package and is sample rate, filter corner frequencies, and output word rate are specified over the industrial temperature range from set by the crystal oscillator or external clock frequency. –40°C to +85°C. Data can be read from the device in either serial or parallel Two input modes are provided, allowing both unipolar and format. A stereo mode allows data from two devices to share a bipolar input ranges. single serial data line. All interface modes offer easy, high speed connections to modern digital signal processors.
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Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS CIRCUIT DESCRIPTION APPLYING THE AD7723 ANALOG INPUT RANGE ANALOG INPUT DRIVING THE ANALOG INPUTS APPLYING THE REFERENCE CLOCK GENERATION SYSTEM SYNCHRONIZATION DATA INTERFACING PARALLEL INTERFACE SERIAL INTERFACE TWO-CHANNEL MULTIPLEXED OPERATION SERIAL INTERFACE TO DSPs AD7723 TO ADSP-21xx INTERFACE AD7723 TO SHARC INTERFACE AD7723 TO DSP56002 INTERFACE AD7723 TO TMS320C5x INTERFACE GROUNDING AND LAYOUT OUTLINE DIMENSIONS ORDERING GUIDE