Datasheet AD7470, AD7472 (Analog Devices) - 8

AD7470/AD7472 PIN FUNCTION DESCRIPTIONS (continued) Mnemonic Function
DGND Digital Ground. This is the ground reference point for all digital circuitry on the AD7470 and AD7472. The DGND and AGND voltages should ideally be at the same potential and must not be more than 0.3 V apart even on a transient basis. VIN Analog Input. Single-ended analog input channel. The input range is 0 V to REF IN. The analog input presents a high dc input impedance. VDRIVE Supply Voltage for the Output Drivers, 2.7 V to 5.25 V. This voltage determines the output high voltage for the data output pins. It allows AVDD and DVDD to operate at 5 V (and maximize the dynamic performance of the (ADC), while the digital outputs can interface to 3 V logic. DB0–DB9/11 Data Bit 0 to Data Bit 9 (AD7470) and DB11 (AD7472). Parallel digital outputs that provide the conversion result for the part. These are three-state outputs that are controlled by CS and RD. The output high voltage level for these outputs is determined by the VDRIVE input. –8– REV. B Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ORDERING GUIDE PIN CONFIGURATIONS PIN FUNCTION DESCRIPTIONS TERMINOLOGY Integral Nonlinearity Differential Nonlinearity Offset Error Gain Error Track-and-Hold Acquisition Time Signal to (Noise + Distortion) Ratio Total Harmonic Distortion (THD) Peak Harmonic or Spurious Noise Intermodulation Distortion Aperture Delay Aperture Jitter CIRCUIT DESCRIPTION CONVERTER OPERATION TYPICAL CONNECTION DIAGRAM ADC TRANSFER FUNCTION AC ACQUISITION TIME Reference Input DC ACQUISITION TIME ANALOG INPUT CLOCK SOURCES PARALLEL INTERFACE OPERATING MODES Mode 1 (High Speed Sampling) Mode 2 (Sleep Mode) Burst Mode VDRIVE POWER-UP Power vs. Throughput Mode 1 Mode 2 Typical Performance Characteristics GROUNDING AND LAYOUT POWER SUPPLIES MICROPROCESSOR INTERFACING AD7470/AD7472 to ADSP-2185 Interface AD7470/AD7472 to ADSP-21065 Interface AD7470/AD7472 to TMS320C25 Interface AD7470/AD7472 to PIC17C4x Interface AD7470/AD7472 to 80C186 Interface OUTLINE DIMENSIONS Revision History