AD7798BRUZ Analog Devices Inc, AD7798BRUZ Datasheet
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AD7798BRUZ
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AD7798BRUZ Summary of contents
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FEATURES RMS noise 4.17 Hz (AD7799 16.7 Hz (AD7799 4.17 Hz (AD7798 16.7 Hz (AD7798) Current: 380 μA typical Power-down: 1 μA maximum Low noise, programmable gain, instrumentation ...
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AD7798/AD7799 TABLE OF CONTENTS Features .............................................................................................. 1 Interface ............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Timing Characteristics..................................................................... 6 Absolute Maximum Ratings............................................................ 8 ESD Caution.................................................................................. 8 Pin Configuration and ...
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SPECIFICATIONS 5.25 V; GND = 0 V; REFIN(+) = otherwise noted. Table 1. Parameter ADC CHANNEL Output Update Rate 2 No Missing Codes Resolution Output ...
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AD7798/AD7799 Parameter REFERENCE External REFIN Voltage 2 Reference Voltage Range 2 Absolute REFIN Voltage Limits Average Reference Input Current Average Reference Input Current Drift Normal Mode Rejection Common-Mode Rejection Reference Detect Levels LOW-SIDE POWER SWITCH Allowable Current ...
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Parameter 2 SYSTEM CALIBRATION Full-Scale Calibration Limit Zero-Scale Calibration Limit Input Span 7 POWER REQUIREMENTS Power Supply Voltage AV – GND DD DV – GND DD Power Supply Currents I Current DD I (Power-Down Mode Temperature range is ...
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AD7798/AD7799 TIMING CHARACTERISTICS 5.25 V, GND = 0 V, Input Logic Input Logic Table Parameter Limit ...
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CS ( MSB DOUT/RDY ( SCLK ( INPUT OUTPUT Figure 3. Read Cycle Timing Diagram CS ( SCLK ( DIN (I) MSB ...
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AD7798/AD7799 ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 3. Parameter Rating AV to GND −0 GND −0 Analog Input Voltage to GND −0.3 V ...
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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 4. Pin Function Descriptions Pin No. Mnemonic Description 1 SCLK Serial Clock Input. This serial clock input is for data transfers to and from the ADC. The SCLK has a Schmitt-triggered input, making the ...
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AD7798/AD7799 OUTPUT NOISE AND RESOLUTION SPECIFICATIONS AD7798 Table 5 shows the AD7798 output rms noise for some update rates and gain settings. The numbers given are for the bipolar input range with a 2.5 V reference. These numbers are typical ...
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AD7799 Table 7 shows the AD7799 output rms noise for some update rates and gain settings. The numbers given are for the bipolar input range with a 2.5 V reference. These numbers are typical and are generated with a differential ...
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AD7798/AD7799 TYPICAL PERFORMANCE CHARACTERISTICS 8388640 8388630 8388620 8388610 8388600 8388590 8388580 0 200 400 SAMPLES Figure 6. AD7799 Noise ( /2, Gain = 64, Update Rate = 4.17 Hz) REF CODE ...
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ON-CHIP REGISTERS The ADC is controlled and configured via a number of on-chip registers, which are described on the following pages. In the following descriptions, set implies a Logic 1 state and cleared implies a Logic 0 state, unless otherwise ...
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AD7798/AD7799 STATUS REGISTER RS2, RS1, RS0 = Power-On/Reset = 0x80 (AD7798)/0x88 (AD7799) The status register is an 8-bit, read-only register. To access the status register, the user must write to the communication register, select the next operation ...
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Table 13. Operating Modes MD2 MD1 MD0 Mode Continuous-Conversion Mode (Default). In continuous-conversion mode, the ADC continuously performs conversions and places the result in the data register. RDY goes low when a conversion is complete. After power-on, ...
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AD7798/AD7799 CONFIGURATION REGISTER RS2, RS1, RS0 = Power-On/Reset = 0x0710 The configuration register is a 16-bit register from which data can be read or to which data can be written. This register is used to configure the ...
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DATA REGISTER RS2, RS1, RS0 = Power-On/Reset = 0x0000(00) The conversion result from the ADC is stored in the data register. This is a read-only register. Upon completion of a read operation from this register, the RDY ...
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AD7798/AD7799 ADC CIRCUIT INFORMATION AV DD IN+ OUT– OUT+ IN– OVERVIEW The AD7798/AD7799 are low power ADCs that each incorporate a ∑-Δ modulator, a buffer, an in-amp, and on-chip digital filtering intended for the measurement of wide dynamic range, low ...
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FREQUENCY (Hz) Figure 14. Filter Profile with Update Rate = 242 Hz 0 –10 –20 –30 –40 –50 –60 0 1000 2000 3000 4000 5000 6000 FREQUENCY (Hz) Figure 15. ...
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AD7798/AD7799 Single-Conversion Mode In single-conversion mode, the AD7798/AD7799 is placed in power-down mode after conversions. When a single conversion is initiated by setting MD2, MD1, and MD0 and 1 in the mode register, the AD7798/AD7799 powers up, ...
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Continuous Read Rather than write to the communication register to access the data each time a conversion is complete, the AD7798/AD7799 can be configured so that the conversions are placed on the DOUT/ RDY line automatically. By writing 01011100 to ...
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AD7798/AD7799 CIRCUIT DESCRIPTION ANALOG INPUT CHANNEL The AD7798/AD7799 each have three differential analog input channels. These are connected to the on-chip buffer amplifier when the devices are operated in buffered mode, and directly to the modulator when the devices are ...
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DATA OUTPUT CODING When the ADC is configured for unipolar operation, the output code is natural (straight) binary with a zero differential input voltage resulting in a code of 00...00, a midscale voltage resulting in a code of 100...000, and ...
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AD7798/AD7799 AV MONITOR DD Along with converting external voltages, the ADC can be used to monitor the voltage on the AV pin. When Bits CH2 to CH0 DD equal 1, the voltage on the AV pin is internally attenuated by ...
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GROUNDING AND LAYOUT Because the analog inputs and reference inputs of the ADC are differential, most of the voltages in the analog modulator are common-mode voltages. The excellent common-mode reject- ion of the parts removes common-mode noise on these inputs. ...
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AD7798/AD7799 APPLICATIONS INFORMATION The AD7798/AD7799 provide a low cost, high resolution analog-to-digital function. Because the analog-to-digital function is provided by a ∑-Δ architecture, the parts are more immune to noisy environments, making them ideal for use in sensor measurement and ...
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... OUTLINE DIMENSIONS 0.15 0.05 ORDERING GUIDE Model Temperature Range 1 AD7798BRUZ –40°C to +105°C 1 AD7798BRUZ-REEL –40°C to +105°C EVAL-AD7798EB AD7799BRU –40°C to +105°C AD7799BRU-REEL –40°C to +105°C 1 AD7799BRUZ –40°C to +105°C 1 AD7799BRUZ-REEL –40°C to +105°C EVAL-AD7799EB RoHS Compliant Part ...
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AD7798/AD7799 NOTES ©2005–2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04856-0-3/07(A) Rev Page ...