Datasheet AD7821 (Analog Devices) - 3

AD7821–SPECIFICATIONS VDD = +5 V
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5%, GND = 0 V. Unipolar Input Range: VSS = GND, VREF(+) = 5 V, VREF(–) = GND. Bipolar Input Range: VSS = –5 V
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5%, VREF(+) = 2.5 V, VREF(–) = –2.5 V. These test conditions apply unless otherwise stated. All specifications TMIN to TMAX unless otherwise noted. Specifications apply for RD Mode (Pin 7 = 0 V). Parameter K Version1 B, T Versions Unit Comments
UNIPOLAR INPUT RANGE Resolution2 8 8 Bits Total Unadjusted Error3 ±1 ±1 LSB max Minimum Resolution for which No Missing Codes are Guaranteed 8 8 Bits BIPOLAR INPUT RANGE Resolution2 8 8 Bits Zero Code Error ±1 ±1 LSB max Full Scale Error ±1 ±1 LSB max Signal-to-Noise Ratio (SNR)3 45 45 dB min VIN = 99.85 kHz Full-Scale Sine Wave with fSAMPLING = 500 kHz Total Harmonic Distortion (THD)3 –50 –50 dB max VIN = 99.85 kHz Full-Scale Sine Wave with fSAMPLING = 500 kHz Peak Harmonic or Spurious Noise3 –50 –50 dB max VIN = 99.85 kHz Full-Scale Sine Wave with fSAMPLING = 500 kHz Intermodulation Distortion (IMD)3 fa (84.72 kHz) and fb (94.97 kHz) Full-Scale Sine Waves with fSAMPLING = 500 kHz –50 –50 dB max Second Order Terms –50 –50 dB max Third Order Terms Slew Rate, Tracking3 1.6 1.6 V/µs max 2.36 2.36 V/µs typ REFERENCE INPUT Input Resistance 1.0/4.0 1.0/4.0 kΩ min/kΩ max VREF(+) Input Voltage Range VREF(–)/VDD VREF(–)/VDD V min/V max VREF(–) Input Voltage Range VSS/VREF(+) VSS/VREF(+) V min/V max ANALOG INPUT Input Voltage Range VREF(–)/VREF(+) VREF(–)/VREF(+) V min/ max Input Leakage Current ±3 ±3 µA max –5 V ≤ VIN ≤ +5 V Input Capacitance 55 55 pF typ LOGIC INPUTS CS, WR, RD VINH 2.4 2.4 V min VINL 0.8 0.8 V max IINH (CS, RD) 1 1 µA max IINH (WR) 3 3 µA max IINL –1 –1 µA max Input Capacitance4 8 8 pF max Typically 5 pF MODE VINH 3.5 3.5 V min VINL 1.5 1.5 V max IINH 200 200 µA max 50 µA typ IINL –1 –1 µA max Input Capacitance4 8 8 pF max Typically 5 pF LOGIC OUTPUTS DB0–DB7, OFL, INT VOH 4.0 4.0 V min ISOURCE = 360 µA VOL 0.4 0.4 V max ISINK = 1.6 mA IOUT (DB0–DB7) ±3 ±3 µA max Floating State Leakage Output Capacitance4 (DB0–DB7) 8 8 pF max Typically 5 pF RDY VOL 0.4 0.4 V max ISINK = 2.6 mA I ± OUT 3 ±3 µA max Floating State Leakage Output Capacitance4 8 8 pF max Typically 5 pF POWER SUPPLY I 5 DD 20 20 mA max CS = RD = 0 V ISS 100 100 µA max CS = RD = 0 V Power Dissipation 50 50 mW typ Power Supply Sensitivity ±1/4 ±1/4 LSB max ±1/16 LSB typ, VDD = 4.75 V to 5.25 V, (VREF(+) = 4.75 V max for Unipolar Mode) NOTES 1Temperature Ranges are as follows: K Version = –40°C to +85°C; B Version = –40°C to +85°C; T Version = –55°C to +125°C. 21 LSB = 19.53 mV for both the unipolar (0 V to +5 V) and bipolar (–2.5 V to +2.5 V) input ranges. 3See Terminology. 4Sample tested at +25°C to ensure compliance. 5See Typical Performance Characteristics. Specifications subject to change without notice. –2– REV. B Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS SPECIFICATIONS Test Circuits ORDERING GUIDE ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATIONS PIN FUNCTION DESCRIPTIONS TERMINOLOGY LEAST SIGNIFICANT BIT (LSB) TOTAL UNADJUSTED ERROR SLEW RATE TOTAL HARMONIC DISTORTION INTERMODULATION DISTORTION SIGNAL-TO-NOISE RATIO PEAK HARMONIC OR SPURIOUS NOISE Typical Performance Characteristics CIRCUIT INFORMATION BASIC DESCRIPTION OPERATING SEQUENCE REFERENCE AND INPUT INPUT CURRENT INPUT TRANSIENTS INHERENT TRACK-AND-HOLD SINUSOIDAL INPUTS DIGITAL SIGNAL PROCESSING APPLICATIONS SIGNAL-TO-NOISE RATIO AND DISTORTION EFFECTIVE NUMBER OF BITS INTERMODULATION DISTORTION HISTOGRAM PLOT DIGITAL INTERFACE RD Mode (MODE = 0) WR-RD Mode (MODE = 1) MICROPROCESSOR INTERFACING AD7821 – 68008 INTERFACE AD7821 – 8088 INTERFACE AD7821 – TMS32010 INTERFACE AD7821 – 8051 INTERFACE APPLYING THE AD7821 UNIPOLAR OPERATION BIPOLAR OPERATION 16-CHANNEL TELECOM A/D CONVERTER SIMULTANEOUS SAMPLING ADCS OUTLINE DIMENSIONS Revision History