Datasheet AD7707 (Analog Devices) - 8

ManufacturerAnalog Devices
Description3 V/5 V, ±10 V Input Range, 1 mW 3-Channel 16-Bit, Sigma-Delta ADC
Pages / Page53 / 8 — AD7707. Parameter. B Version1. Unit Conditions/Comments. Table 2. Low …
RevisionB
File Format / SizePDF / 788 Kb
Document LanguageEnglish

AD7707. Parameter. B Version1. Unit Conditions/Comments. Table 2. Low Level Input Channels, AIN1 and AIN2 Gain. 8 to 128

AD7707 Parameter B Version1 Unit Conditions/Comments Table 2 Low Level Input Channels, AIN1 and AIN2 Gain 8 to 128

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AD7707 Parameter B Version1 Unit Conditions/Comments
Normal Mode Power Dissipation17 AVDD = DVDD = 3 V; digital inputs = 0 V or DVDD; external MCLK IN excluding dissipation in the AIN3 attenuator 1.05 mW max Typically 0.84 mW; BUF = 0; fCLK IN = 1 MHz, all gains 2.04 mW max Typically 1.53 mW; BUF = 1; fCLK IN = 1 MHz; all gains 1.35 mW max Typically 1.11 mW; BUF = 0; fCLK IN = 2.4576 MHz, gain = 1 to 4 2.34 mW max Typically 1.9 mW; BUF = 1; fCLK IN = 2.457 6 MHz; gain = 1 to 4 Normal Mode Power Dissipation17 AVDD = DVDD = 5 V; digital inputs = 0 V or DVDD; external MCLKIN 2.1 mW max Typically 1.75 mW; BUF = 0; fCLK IN = 1 MHz; all gains 3.75 mW max Typically 2.9 mW; BUF = 1; fCLK IN = 1 MHz; all gains 3.1 mW max Typically 2.6 mW; BUF = 0; fCLK IN = 2.4576 MHz 4.75 mW max Typically 3.75 mW; BUF = 1; fCLK IN = 2.4576 MHz Standby (Power-Down) Current20 18 μA max External MCLK IN = 0 V or DVDD; typically 9 μA; AVDD = 5 V 8 μA max External MCLK IN = 0 V or DVDD; typically 4 μA; AVDD = 3 V 1 Temperature range as follows: B Version, −40°C to +85°C. 2 These numbers are established from characterization or design at initial product release. 3 A calibration is effectively a conversion so these errors are of the order of the conversion noise shown in Table 7 and Table 9 for the low level input channels AIN1 and AIN2. This applies after calibration at the temperature of interest. 4 Recalibration at any temperature removes these drift errors. 5 Positive full-scale error includes zero-scale errors (unipolar offset error or bipolar zero error) and applies to both unipolar and bipolar input ranges. 6 Full-scale drift includes zero-scale drift (unipolar offset drift or bipolar zero drift) and applies to both unipolar and bipolar input ranges. 7 Gain error does not include zero-scale errors. It is calculated as full-scale error—unipolar offset error for unipolar ranges and full-scale error—bipolar zero error for bipolar ranges. 8 Gain error drift does not include unipolar offset drift/bipolar zero drift. It is effectively the drift of the part if POMZzero-scale calibrations were performed. 9 Error is removed following a system calibration. 10 This common-mode voltage range is allowed provided that the input voltage on analog inputs does not go more positive than AVDD + 30 mV or go more negative than AGND − 100 mV. Parts are functional with voltages down to AGND − 200 mV, but with increased leakage at high temperature. 11 The analog input voltage range on AIN(+) is given here with respect to the voltage on LCOM on the low level input channels (AIN1 and AIN2) and is given with respect to the HCOM input on the high level input channel, AIN3. The absolute voltage on the low level analog inputs should not go more positive than AVDD + 100 mV, or go more negative than GND − 100 mV for specified performance. Input voltages of AGND − 200 mV can be accommodated, but with increased leakage at high temperature. 12 VREF = REF IN(+) − REF IN(−). 13 These logic output levels apply to the MCLK OUT only when it is loaded with one CMOS load. 14 Sample tested at +25°C to ensure compliance. 15 After calibration, if the analog input exceeds positive full scale, the converter outputs all 1s. If the analog input is less than negative full scale, the device outputs all 0s. 16 These calibration and span limits apply provided that the absolute voltage on the analog inputs does not exceed AVDD + 30 mV or go more negative than AGND − mV. The offset calibration limit applies to both the unipolar zero point and the bipolar zero point. 17 When using a crystal or ceramic resonator across the MCLK pins as the clock source for the device, the DVDD current and power dissipation varies depending on the crystal or resonator type (see the Clocking and Oscillator Circuit section). 18 Measured at dc and applies in the selected pass band. PSRR at 50 Hz exceeds 120 dB with filter notches of 25 Hz or 50 Hz. PSRR at 60 Hz exceeds 120 dB with filter notches of 20 Hz or 60 Hz. 19 PSRR depends on both gain and AVDD. See Table 2 and Table 3. 20 If the external master clock continues to run in standby mode, the standby current increases to 150 μA typical at 5 V and 75 μA typical at 3 V. When using a crystal or ceramic resonator across the MCLK pins as the clock source for the device, the internal oscillator continues to run in standby mode and the power dissipation depends on the crystal or resonator type (see the Standby Mode section).
Table 2. Low Level Input Channels, AIN1 and AIN2 Gain 1 2 4 8 to 128
AVDD = 3 V 86 78 85 93 AVDD = 5 V 90 78 84 91
Table 3. High Level Input Channel, AIN3 Gain 1 2 4 8 to 128
AVDD = 3 V 68 60 67 75 AVDD = 5 V 72 60 66 73 Rev. B | Page 7 of 52 Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS OUTPUT NOISE OUTPUT NOISE FOR LOW LEVEL INPUT CHANNELS (5 V OPERATION) OUTPUT NOISE FOR LOW LEVEL INPUT CHANNELS (3 V OPERATION) OUTPUT NOISE FOR HIGH LEVEL INPUT CHANNEL AIN3 (5 V OPERATION) OUTPUT NOISE FOR HIGH LEVEL INPUT CHANNEL AIN3 (3 V OPERATION) ON-CHIP REGISTERS COMMUNICATIONS REGISTER (RS2, RS1, RS0 = 0, 0, 0) Setup Register (RS2, RS1, RS0 = 0, 0, 1); Power-On/Reset Status: 0x01 Clock Register (RS2, RS1, RS0 = 0, 1, 0); Power-On/Reset Status: 0x05 Data Register (RS2, RS1, RS0 = 0, 1, 1) Test Register (RS2, RS1, RS0 = 1, 0, 0); Power-On/Reset Status: 0x00 Zero-Scale Calibration Register (RS2, RS1, RS0 = 1, 1, 0); Power-On/Reset Status: 0x1F4000 Full-Scale Calibration Register (RS2, RS1, RS0 = 1, 1, 1); Power-On/Reset Status: 0x5761AB CALIBRATION SEQUENCES CIRCUIT DESCRIPTION ANALOG INPUT ANALOG INPUT RANGES INPUT SAMPLE RATE BIPOLAR/UNIPOLAR INPUTS REFERENCE INPUT DIGITAL FILTERING FILTER CHARACTERISTICS POSTFILTERING ANALOG FILTERING CALIBRATION SELF-CALIBRATION SYSTEM CALIBRATION SPAN AND OFFSET LIMITS ON THE LOW LEVEL INPUT CHANNELS, AIN1 AND AIN2 SPAN AND OFFSET LIMITS ON THE HIGH LEVEL INPUT CHANNEL AIN3 POWER-UP AND CALIBRATION USING THE AD7707 CLOCKING AND OSCILLATOR CIRCUIT SYSTEM SYNCHRONIZATION RESET INPUT STANDBY MODE ACCURACY DRIFT CONSIDERATIONS POWER SUPPLIES SUPPLY CURRENT GROUNDING AND LAYOUT DIGITAL INTERFACE CONFIGURING THE AD7707 MICROCOMPUTER/MICROPROCESSOR INTERFACING AD7707 TO 68HC11 INTERFACE AD7707 TO 8XC51 INTERFACE CODE FOR SETTING UP THE AD7707 C CODE FOR INTERFACING AD7707 TO 68HC11 APPLICATIONS INFORMATION DATA ACQUISITION SMART VALVE/ACTUATOR CONTROL PRESSURE MEASUREMENT THERMOCOUPLE MEASUREMENT RTD MEASUREMENT CHART RECORDERS ACCOMMODATING VARIOUS HIGH LEVEL INPUT RANGES TYPICAL INPUT CURRENTS OUTPUT NOISE FOR HIGH LEVEL INPUT CHANNEL, AIN3 5 V OPERATION 3 V OPERATION OUTLINE DIMENSIONS ORDERING GUIDE