Datasheet AD7771 (Analog Devices) - 6

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Data Sheet AD7771 SPECIFICATIONS
AVDD1x = 1.65 V, AVSSx1 = −1.65 V (dual supply operation), AVDD1x = 3.3 V, AVSSx = analog ground (AGND) (single-supply operation), AVDD2x − AVSSx = 2.2 V to 3.6 V; IOVDD = 1.8 V to 3.6 V; DGND = 0 V, REFx+/REFx− = 2.5 V AVSSx (internal/external), master clock (MCLK) = 8192 kHz for high resolution mode and 4096 kHz for low power mode, ODR = 128 kSPS for high resolution mode and 32 kSPS for low power mode; all specifications at TMIN to TMAX, unless otherwise noted.
Table 1. Parameter Test Conditions/Comments Min Typ Max Unit
ANALOG INPUTS Differential Input Voltage Range VREF = (REFx+ − REFx−) ±VREF/PGAGAIN V Single-Ended Input Voltage Range 0 to VREF/PGAGAIN V AINx± Common-Mode Input Range AVSSx + 0.10 (AVDD1x + AVDD1x − 0.10 V AVSSx)/2 Absolute AINx± Voltage Limits AVSSx + 0.10 AVDD1x − 0.10 V DC Input Current Differential High resolution mode ±4 nA Low power mode ±1 nA Single-Ended High resolution mode ±8 nA Low power mode ±2 nA Input Current Drift 50 pA/°C AC Input Capacitance 8 pF PROGRAMMABLE GAIN AMPLIFIER (PGA) Gain Settings (PGAGAIN) 1, 2, 4, or 8 Bandwidth Smal Signal High resolution mode 2 MHz Low power mode 512 kHz Large Signal High resolution mode See Figure 39, Figure 40, and Figure 44 Low power mode See Figure 42, Figure 43, and Figure 47 REFERENCE Internal Initial Accuracy REF_OUT, TA = 25°C 2.495 2.5 2.505 V Temperature Coefficient ±10 ±38 ppm/°C Reference Load Current, IL −10 +10 mA DC Power Supply Rejection Line regulation 95 dB Load Regulation, ∆VOUT/∆IL 100 µV/mA Voltage Noise, eN p-p 0.1 Hz to 10 Hz 6.8 µV rms Voltage Noise Density, eN 1 kHz, 2.5 V reference 273.5 nV/√Hz Turn On Settling Time 100 nF 1.5 ms External Input Voltage VREF = (REFx+ − REFx−) 1 2.5 AVDD1x V Buffer Headroom AVSSx + 0.1 AVDD1x − 0.1 V REFx− Input Voltage AVSSx AVDD1x − REFx+ V Average REFx± Input Current Current per channel Reference buffer disabled, 18 µA/V high resolution mode Reference buffer precharge mode 600 nA/V (pre-Q), high resolution mode Reference buffer disabled, 4.5 µA/V low power mode Reference buffer pre-Q, 100 nA/V low power mode Reference buffer enabled, 12 nA/V high resolution mode Reference buffer enabled, 5 nA/V low power mode Rev. 0 | Page 5 of 98 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS DOUTx TIMING CHARACTERISTISTICS SPI TIMING CHARACTERISTISTICS SYNCHRONIZATION PINS AND RESET TIMING CHARACTERISTICS SAR ADC TIMING CHARACTERISTISTICS GPIO SRC UPDATE TIMING CHARACTERISTISTICS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION ANALOG INPUTS TRANSFER FUNCTION CORE SIGNAL CHAIN CAPACITIVE PGA INTERNAL REFERENCE AND REFERENCE BUFFERS INTEGRATED LDOs CLOCKING AND SAMPLING DIGITAL RESET AND SYNCHRONIZATION PINS DIGITAL FILTERING SHUTDOWN MODE CONTROLLING THE AD7771 PIN CONTROL MODE SPI CONTROL Functionality Available in SPI Control Mode Offset and Gain Correction SPI Control Functionality Global Control Functions Per Channel Functions Phase Adjustment PGA Gain Decimation GPIOx Pins Σ-Δ Reference Configuration Power Modes Sinc3 and Sinc5 Filters LDO Bypassing DIGITAL SPI SPI CRC—Checksum Protection (SPI Control Mode) SPI Read/Write Register Mode (SPI Control Mode) SPI SAR Diagnostic Mode (SPI Control Mode) Σ-Δ Data, ADC Mode SPI Software Reset RMS NOISE AND RESOLUTION HIGH RESOLUTION MODE LOW POWER MODE DIAGNOSTICS AND MONITORING SELF DIAGNOSTICS ERROR General Errors MCLK Switch Error (SPI Control Mode) Reset Detection Internal LDO Status ROM and Memory Map CRC Σ-Δ ADC Errors Reference Detect (SPI Control Mode) Overvoltage and Undervoltage Events Modulator Saturation Filter Saturation Output Saturation SPI Transmission Errors (SPI Control Mode) CRC Checksum Error SCLK Counter Invalid Read Invalid Write MONITORING USING THE AD7771 SAR ADC(SPI CONTROL MODE) Temperature Sensor Σ-Δ ADC DIAGNOSTICS (SPI CONTROL MODE) Σ-∆ OUTPUT DATA ADC CONVERSION OUTPUT—HEADER AND DATA CRC Header Error Header (SPI Control Mode) SAMPLE RATE CONVERTER (SRC) (SPI CONTROL MODE) SRC Bandwidth SRC Group Delay Settling Time DATA OUTPUT INTERFACE DOUT3 to DOUT0 Data Interface Standalone Mode Daisy-Chain Mode Minimum DCLKx Frequency SPI CALCULATING THE CRC CHECKSUM Σ-Δ CRC Checksum SPI Control Mode Checksum REGISTER SUMMARY REGISTER DETAILS CHANNEL 0 CONFIGURATION REGISTER CHANNEL 1 CONFIGURATION REGISTER CHANNEL 2 CONFIGURATION REGISTER CHANNEL 3 CONFIGURATION REGISTER CHANNEL 4 CONFIGURATION REGISTER CHANNEL 5 CONFIGURATION REGISTER CHANNEL 6 CONFIGURATION REGISTER CHANNEL 7 CONFIGURATION REGISTER DISABLE CLOCKS TO ADC CHANNEL REGISTER CHANNEL 0 SYNC OFFSET REGISTER CHANNEL 1 SYNC OFFSET REGISTER CHANNEL 2 SYNC OFFSET REGISTER CHANNEL 3 SYNC OFFSET REGISTER CHANNEL 4 SYNC OFFSET REGISTER CHANNEL 5 SYNC OFFSET REGISTER CHANNEL 6 SYNC OFFSET REGISTER CHANNEL 7 SYNC OFFSET REGISTER GENERAL USER CONFIGURATION 1 REGISTER GENERAL USER CONFIGURATION 2 REGISTER GENERAL USER CONFIGURATION 3 REGISTER DATA OUTPUT FORMAT REGISTER MAIN ADC METER AND REFERENCE MUX CONTROL REGISTER GLOBAL DIAGNOSTICS MUX REGISTER GPIO CONFIGURATION REGISTER GPIO DATA REGISTER BUFFER CONFIGURATION 1 REGISTER BUFFER CONFIGURATION 2 REGISTER CHANNEL 0 OFFSET UPPER BYTE REGISTER CHANNEL 0 OFFSET MIDDLE BYTE REGISTER CHANNEL 0 OFFSET LOWER BYTE REGISTER CHANNEL 0 GAIN UPPER BYTE REGISTER CHANNEL 0 GAIN MIDDLE BYTE REGISTER CHANNEL 0 GAIN LOWER BYTE REGISTER CHANNEL 1 OFFSET UPPER BYTE REGISTER CHANNEL 1 OFFSET MIDDLE BYTE REGISTER CHANNEL 1 OFFSET LOWER BYTE REGISTER CHANNEL 1 GAIN UPPER BYTE REGISTER CHANNEL 1 GAIN MIDDLE BYTE REGISTER CHANNEL 1 GAIN LOWER BYTE REGISTER CHANNEL 2 OFFSET UPPER BYTE REGISTER CHANNEL 2 OFFSET MIDDLE BYTE REGISTER CHANNEL 2 OFFSET LOWER BYTE REGISTER CHANNEL 2 GAIN UPPER BYTE REGISTER CHANNEL 2 GAIN MIDDLE BYTE REGISTER CHANNEL 2 GAIN LOWER BYTE REGISTER CHANNEL 3 OFFSET UPPER BYTE REGISTER CHANNEL 3 OFFSET MIDDLE BYTE REGISTER CHANNEL 3 OFFSET LOWER BYTE REGISTER CHANNEL 3 GAIN UPPER BYTE REGISTER CHANNEL 3 GAIN MIDDLE BYTE REGISTER CHANNEL 3 GAIN LOWER BYTE REGISTER CHANNEL 4 OFFSET UPPER BYTE REGISTER CHANNEL 4 OFFSET MIDDLE BYTE REGISTER CHANNEL 4 OFFSET LOWER BYTE REGISTER CHANNEL 4 GAIN UPPER BYTE REGISTER CHANNEL 4 GAIN MIDDLE BYTE REGISTER CHANNEL 4 GAIN LOWER BYTE REGISTER CHANNEL 5 OFFSET UPPER BYTE REGISTER CHANNEL 5 OFFSET MIDDLE BYTE REGISTER CHANNEL 5 OFFSET LOWER BYTE REGISTER CHANNEL 5 GAIN UPPER BYTE REGISTER CHANNEL 5 GAIN MIDDLE BYTE REGISTER CHANNEL 5 GAIN LOWER BYTE REGISTER CHANNEL 6 OFFSET UPPER BYTE REGISTER CHANNEL 6 OFFSET MIDDLE BYTE REGISTER CHANNEL 6 OFFSET LOWER BYTE REGISTER CHANNEL 6 GAIN UPPER BYTE REGISTER CHANNEL 6 GAIN MIDDLE BYTE REGISTER CHANNEL 6 GAIN LOWER BYTE REGISTER CHANNEL 7 OFFSET UPPER BYTE REGISTER CHANNEL 7 OFFSET MIDDLE BYTE REGISTER CHANNEL 7 OFFSET LOWER BYTE REGISTER CHANNEL 7 GAIN UPPER BYTE REGISTER CHANNEL 7 GAIN MIDDLE BYTE REGISTER CHANNEL 7 GAIN LOWER BYTE REGISTER CHANNEL 0 STATUS REGISTER CHANNEL 1 STATUS REGISTER CHANNEL 2 STATUS REGISTER CHANNEL 3 STATUS REGISTER CHANNEL 4 STATUS REGISTER CHANNEL 5 STATUS REGISTER CHANNEL 6 STATUS REGISTER CHANNEL 7 STATUS REGISTER CHANNEL 0/CHANNEL 1 DSP ERRORS REGISTER CHANNEL 2/CHANNEL 3 DSP ERRORS REGISTER CHANNEL 4/CHANNEL 5 DSP ERRORS REGISTER CHANNEL 6/CHANNEL 7 DSP ERRORS REGISTER CHANNEL 0 TO CHANNEL 7 ERROR REGISTER ENABLE REGISTER GENERAL ERRORS REGISTER 1 GENERAL ERRORS REGISTER 1 ENABLE GENERAL ERRORS REGISTER 2 GENERAL ERRORS REGISTER 2 ENABLE ERROR STATUS REGISTER 1 ERROR STATUS REGISTER 2 ERROR STATUS REGISTER 3 DECIMATION RATE (N) MSB REGISTER DECIMATION RATE (N) LSB REGISTER DECIMATION RATE (IF) MSB REGISTER DECIMATION RATE (IF) LSB REGISTER SRC LOAD SOURCE AND LOAD UPDATE REGISTER OUTLINE DIMENSIONS ORDERING GUIDE