Locale Icon
English
  • Forums

    Popular Forums

    • LTspice
    • RF and Microwave
    • Video
    • Power Management
    • Precision ADCs
    • FPGA Reference Designs
    • Linux Software Drivers

    Product Forums

    • Amplifiers
    • Microcontrollers
    • Clock and Timing
    • Data Converters
    • Direct Digital Synthesis (DDS)
    • Energy Monitoring and Metering
    • Interface and Isolation
    • MEMS Inertial Sensors
    • Power Management
    • Processors and DSP
    • Switches/Multiplexers
    • Temperature Sensors
    • Voltage References
    View All

    Application Forums

    • A2B
    • Audio
    • Automated Test Equipment (ATE)
    • Condition-Based Monitoring
    • Depth, Perception & Ranging Technologies
    • Embedded Vision Sensing Library
    • Motor Control Hardware Platforms
    • Precision Technology Signal Chains Library
    • Video
    • Wireless Sensor Networks Reference Library

    Design Center Forums

    • ACE Evaluation Software
    • ADEF System Platforms
    • Design Tools and Calculators
    • FPGA Reference Designs
    • Linux Software Drivers
    • Microcontroller no-OS Drivers
    • Reference Designs
    • Signal Chain Power (SCP)
    • Software Interface Tools
    • System Demonstration Platform (SDP) Support
  • Learn

    Highlighted Webinar

    Upcoming Webinar: Simplify High-Accuracy Instrumentation Design with Latest Precision Data Converters

    Join us for an insightful webinar on how ADI’s Precision technology is transforming the landscape of high accuracy instrument design with cutting-edge...

    Places

    • ADI Education Home
    • ADI Webinars
    • GMSL U
    • StudentZone (Analog Dialogue)
    • Video Annex
    • Virtual Classroom

    Libraries

    • 3D ToF Depth Sensing Library
    • Continuous-Wave CMOS Time of Flight (TOF) Library
    • Embedded Vision Sensing Library
    • Gigabit Multimedia Serial Link (GMSL) Library
    • Optical Sensing Library
    • Precision Technology Signal Chains Library
    • Software Modules and SDKs Library
    • Supervisory Circuits Library
    • Wireless Sensor Networks Library

    Latest Webinars

    • Simplifying Connectivity - Remote Controlled (RC) Nodes in a Software Defined Vehicle (SDV)
    • Upcoming Webinar: Simplify High-Accuracy Instrumentation Design with Latest Precision Data Converters
    • Design High Performance Power Systems with Ultralow Noise Technology
    • µModule Solution for Intelligent Motion Control
    • Accelerating Embedded System Development with CodeFusion Studio™︎
    View All Webinars
  • Community Hub

    Challenge Yourself!

      KCC's Quizzes AQQ286 about Right Labels on the Right Boxes containing colored balls

      1. Quote of the week: "Knowledge is knowing a tomato is a fruit. Wisdom is not putting it in a fruit salad" - unknown Sources: commons.wikimedia...

    View All

    What's Brewing

      Quiz! Why a Hybrid Approach Works Blog and Test Your Knowledge

      Quiz! Understand ISO 26262 Compliance Test your knowledge with our quick quiz , based on the blog " Safety in Layers: Why a Hybrid Approach Works ...

    View All

    Places

    • Community Help
    • Logic Lounge
    • Super User Program

    Resources

    • EZ Code of Conduct
    • EZ How To Help Articles
    • Getting Started Guide
    • ADI: Words Matter
    • Community Help Videos
    View All
  • Blogs

    Highlighted Blogs

    Exploring DCM and CCM in SMPS: Part 1 of 6

    Power supplies are the unsung heroes of electronic devices, ensuring that they receive the precise, stable, and clean DC voltages they need to function...

     

    Let’s Take a Field-Bus Trip

    Let’s dive deep into what makes field buses unique compared to each other. Building on our previous blog post, What Makes Field Bus Communication Unique...

    Latest Blogs

    • Countable vs Non-countable Faults
    • Power Your Signal: DAS Networks Unleashed: Part 2 of 4
    • Combining Functional Safety and Availability Using Redundancy
    • Top 3 Engineering Blogs That Captivated Minds on EngineerZone
    • How to Generate a Custom Profile for Optimal System Performance
    Read All Blogs

    ADI Blogs

    • EZ Spotlight
    • The Engineering Mind
  • ContentZone

    Visit ContentZone

    ContentZone

    Technical articles. Blogs. Videos. Your ADI content, all in one place.

    View ContentZone

    Featured Content

    Featured Content Title

    Blurb About Content

    View Content By Industry

    • Aerospace and Defense Systems
    • Automotive Solutions
    • Consumer Technology Solutions
    • Data Center Solutions
    • Energy Solutions
    • Healthcare Solutions
    • Industrial Automation Technology Solutions
    • Instrumentation and Measurement Solutions
    • Intelligent Building Solutions
    • Internet of Things (IoT)
    • Wireless Communication Solutions

    View Content By Technology

    • A2B Audio Bus
    • ADI OtoSense Predictive Maintenance Solutions
    • Dynamic Speaker Management
    • Gallium Nitride (GaN) Technology
    • Gigabit Multimedia Serial Link (GMSL)
    • Industrial Vision
    • Power Solutions
    • Precision Technology
    • RF
    • Security Solutions
    • Sensor Interfaces
    • SmartMesh
  • Partners

    Partner Forums

    • Boston Engineering
    • PalmSens
    • Richardson RFPD
    • Tri-Star Design, Inc.

    Partner Libraries

    • Calian, Advanced Technologies Library
    • Clockworks Signal Processing Library
    • Colorado Engineering Inc. (DBA CAES AT&E) Library
    • Epiq Solutions Library
    • Fidus Library
    • VadaTech Library
    • Vanteon Library
    • X-Microwave Library
EngineerZone
EngineerZone
Precision ADCs
  • Log In
  • User
  • Site
  • Search
OR
Ask a Question
Precision ADCs
  • Data Converters
Precision ADCs
Documents AD7793: Current output compliance voltage and impedance
  • Forums
  • File Uploads
  • FAQs/Docs
  • Members
  • Tags
  • More
  • Cancel
  • +Documents
  • +General: FAQ
  • +AD1139: FAQ
  • +AD7091R Conversion Result Change
  • +AD1556: FAQ
  • +AD1580: FAQ
  • +AD1582: FAQ
  • +AD2S1200: FAQ
  • +AD2S1205: FAQ
  • +AD2S1210: FAQ
  • +AD2S75: FAQ
  • +AD2S80: FAQ
  • +AD2S80A: FAQ
  • +AD2S82A: FAQ
  • +AD2S83: FAQ
  • +AD2S90: FAQ
  • +AD2S99: FAQ
  • +AD4110-1: FAQ
  • +AD411x: FAQ
  • +AD5940: FAQ
  • +AD598: FAQ
  • +AD650: FAQ
  • +AD652: FAQ
  • +AD654: FAQ
  • +AD7091: FAQ
  • +AD7091R-X: FAQ
  • +AD711: FAQ
  • +AD7124-4: FAQ
  • +AD7124-8: FAQ
  • +AD7134: FAQ
  • +AD713: FAQ
  • +AD7142: FAQ
  • +AD7147: FAQ
  • +AD7148: FAQ
  • +AD7150: FAQ
  • +AD7151: FAQ
  • +AD7175-2: FAQ
  • +AD7176-2: FAQ
  • +AD7176: FAQ
  • +AD717x: FAQ
  • +AD7190: FAQ
  • +AD7192: FAQ
  • +AD7193: FAQ
  • +AD7195: FAQ
  • +AD719x: FAQ
  • +AD7265: FAQ
  • +AD7266: FAQ
  • +AD7280: FAQ
  • +AD7291: FAQ
  • +AD7298: FAQ
  • +AD7305: FAQ
  • +AD7321: FAQ
  • +AD7323: FAQ
  • +AD7328: FAQ
  • +AD7366-5: FAQ
  • +AD7367: FAQ
  • +AD736ARZ: FAQ
  • +AD737: FAQ
  • +AD738x : FAQ
  • +AD7398: FAQ
  • +AD7400A: FAQ
  • +AD7401: FAQ
  • +AD7403: FAQ
  • +AD74111: FAQ
  • +AD7415: FAQ
  • +AD7416: FAQ
  • +AD7417: FAQ
  • +AD7418: FAQ
  • +AD7450: FAQ
  • +AD7475: FAQ
  • +AD7484: FAQ
  • +AD7490: FAQ
  • +AD7492: FAQ
  • +AD75019: FAQ
  • +AD7503: FAQ
  • +AD7541A: FAQ
  • +AD7546: FAQ
  • AD7547: FAQ
  • +AD7568: FAQ
  • +AD7578: FAQ
  • +AD7606-4: FAQ
  • +AD7606: FAQ
  • +AD7606B: FAQ
  • +AD7606C: FAQ
  • +AD7608: FAQ
  • +AD7616 FAQ
  • +AD7616-P: FAQ
  • +AD7621: FAQ
  • +AD7625: FAQ
  • +AD7626: FAQ
  • +AD7631: FAQ
  • +AD7653: FAQ
  • +AD7654: FAQ
  • +AD7655: FAQ
  • +AD7656: FAQ
  • +AD7657-1: FAQ
  • +AD7663: FAQ
  • +AD7674: FAQ
  • +AD7675: FAQ
  • +AD7678: FAQ
  • +AD7682: FAQ
  • +AD7683: FAQ
  • +AD7684: FAQ
  • +AD7685: FAQ
  • +AD7688: FAQ
  • +AD7689: FAQ
  • +AD7690: FAQ
  • +AD7691: FAQ
  • +AD7705: FAQ
  • +AD7706: FAQ
  • +AD7707: FAQ
  • +AD7708: FAQ
  • +AD7709: FAQ
  • +AD7710: FAQ
  • +AD7711A: FAQ
  • +AD7712: FAQ
  • +AD7713: FAQ
  • +AD7714: FAQ
  • +AD7714YN: FAQ
  • +AD7715: FAQ
  • +AD7716: FAQ
  • +AD7718: FAQ
  • +AD7719: FAQ
  • +AD7720: FAQ
  • +AD7722: FAQ
  • +AD7725: FAQ
  • +AD7730: FAQ
  • +AD7731: FAQ
  • +AD7732: FAQ
  • +AD7738: FAQ
  • +AD7740: FAQ
  • +AD7741: FAQ
  • +AD7745: FAQ
  • +AD7746: FAQ
  • +AD7747: FAQ
  • +AD7760: FAQ
  • +AD7763: FAQ
  • +AD7766: FAQ
  • +AD7768: FAQ
  • +AD777x: FAQ
  • +AD7780: FAQ
  • +AD7785: FAQ
  • +AD7787: FAQ
  • +AD7788: FAQ
  • +AD7790: FAQ
  • +AD7792: FAQ
  • -AD7793: FAQ
    • AD7793: SPI Communication Issues
    • AD7793: Continous conversion mode
    • AD7793: Digital reading
    • AD7793: external bias voltage connection to thermocouple
    • AD7793: ID register
    • AD7793: Sample rates
    • AD7793: Current output compliance voltage and impedance
    • AD7793: Will the AD7793 ADC continue to sample when the CS is disabled?
    • We clock the AD7793 with an external 128kHz clock which is derived from the microcontrollers clock.
    • Measure current/voltage/resistance using an ADC
    • AD779: How to calculate the internal temperature of the AD7793?
  • +AD7794: FAQ
  • +AD7795: FAQ
  • +AD7798: FAQ
  • +AD7799: FAQ
  • +AD7805: FAQ
  • +AD7808: FAQ
  • +AD7809: FAQ
  • +AD780: FAQ
  • +AD7811: FAQ
  • +AD7812: FAQ
  • +AD7817: FAQ
  • +AD7819: FAQ
  • +AD7821: FAQ
  • +AD7825: FAQ
  • +AD7829: FAQ
  • +AD7835: FAQ
  • +AD7849: FAQ
  • +AD7851: FAQ
  • +AD7854: FAQ
  • +AD7856: FAQ
  • +AD7858: FAQ
  • +AD7859: FAQ
  • +AD7864: FAQ
  • +AD7865 : FAQ
  • +AD7872: FAQ
  • +AD7874: FAQ
  • +AD7879: FAQ
  • +AD7887: FAQ
  • +AD7888: FAQ
  • +AD7891-1: FAQ
  • +AD7891: FAQ
  • +AD7893-2: FAQ
  • +AD7895: FAQ
  • +AD7896: FAQ
  • +AD7899: FAQ
  • +AD7912: FAQ
  • +AD7921: FAQ
  • +AD7924: FAQ
  • +AD7927: FAQ
  • +AD7938: FAQ
  • +AD7942: FAQ
  • +AD7949: FAQ
  • +AD7960: FAQ
  • +AD7961: FAQ
  • +AD797: FAQ
  • +AD7980: FAQ
  • +AD7982: FAQ
  • +AD7984: FAQ
  • +AD7986: FAQ
  • +AD7988-1: FAQ
  • +AD7993: FAQ
  • +AD7994: FAQ
  • +AD7997: FAQ
  • +AD7998: FAQ
  • +ADA2200: FAQ
  • +ADAS1000: FAQ
  • +ADAS3022: FAQ
  • +ADAS3023: FAQ
  • +ADC: FAQ
  • +ADVFC32: FAQ
  • +EVAL-AD7719-EB: FAQ
  • +EVAL-ADAS3022EDZ: FAQ
  • +RDC1740: FAQ
  • +AD4080: FAQ
  • +AD4114: FAQ
  • +AD4116: FAQ
  • +AD4130-8 FAQ
  • +AD4134 FAQ
  • +AD4170: FAQ
  • +AD4858
  • +AD7175-8: FAQ
  • AD73360: FAQ
  • +AD73360AR: FAQ
  • +AD73360L: FAQ
  • +AD7357: FAQ
  • +AD7386-4: FAQ
  • +AD738x-4: FAQ
  • AD7398 SPI Voltage vs VCC
  • +AD7457: FAQ
  • +AD7609: FAQ
  • +AD7656-1: FAQ
  • AD7660: FAQ
  • +AD7665: FAQ
  • +AD7680: FAQ
  • +AD7764: FAQ
  • +AD7778: FAQ
  • AD7892: FAQ
  • +AD7980SRMZ-EP: FAQ
  • +AD7991: FAQ
  • +AD9243: FAQ
  • +AD9260: FAQ
  • +AD9261: FAQ
  • +AD9262: FAQ
  • +AD974: FAQ
  • +AD976A: FAQ
  • +AD977A: FAQ
  • +ADAQ4003: FAQ
  • +ADAQ7768-1: FAQ
  • +ADAQ8092 FAQ
  • +DC590, DC2026, QuikEval: FAQs
  • +Legacy LTC - Sigma Delta ADCs FAQ
  • +LTC2408: FAQ
  • +LTC2497: FAQ
  • +MAX1028: FAQ
  • +MAX1036: FAQ
  • +MAX1037EKA+: FAQ
  • +MAX11040GUU+: FAQ
  • +MAX11043: FAQ
  • +MAX11045: FAQ
  • +MAX11046 16-BIT AD: FAQ
  • +MAX11048: FAQ
  • +MAX11100EUB+: FAQ
  • +MAX11101: FAQ
  • +MAX11103: FAQ
  • +MAX11108: FAQ
  • MAX11125: FAQ
  • +MAX11125ATI+: FAQ
  • +MAX11130: FAQ
  • +MAX11131ATI+: FAQ
  • +MAX11136ATI+: FAQ
  • +MAX11150EVKIT#: FAQ
  • +MAX11154: FAQ
  • MAX11156: FAQ
  • +MAX11156ETC+: FAQ
  • +MAX11158: FAQ
  • +MAX11163: FAQ
  • +MAX11168EUB+: FAQ
  • +MAX11169EUB+: FAQ
  • +MAX11190: FAQ
  • +MAX11190ATE+: FAQ
  • MAX11192: FAQ
  • +MAX11192EVKIT#: FAQ
  • +MAX11200: FAQ
  • +MAX11200EEE+: FAQ
  • +MAX11201: FAQ
  • +MAX11203EEE+: FAQ
  • +MAX11206: FAQ
  • +MAX11207EEE+: FAQ
  • MAX11210: FAQ
  • +MAX11210EEE+: FAQ
  • +MAX11213EEE+T: FAQ
  • MAX11214: FAQ
  • MAX11214EUG+: FAQ
  • +MAX11214EUG+_T1: FAQ
  • +MAX11216: FAQ
  • +MAX11254ATJ+: FAQ
  • +MAX11254EVKIT#: FAQ
  • +MAX11259AWX+T: FAQ
  • +MAX11259PMB#: FAQ
  • +MAX11261BOB#: FAQ
  • +MAX11261ENX+: FAQ
  • +MAX11270EUG+: FAQ
  • +MAX11337ATJ+: FAQ
  • +MAX11410ATI+: FAQ
  • +MAX11608: FAQ
  • +MAX11609EEE+: FAQ
  • +MAX11612EUA+: FAQ
  • +MAX11612EVSYS: FAQ
  • +MAX11614EEE+: FAQ
  • +MAX11615EEE+C78: FAQ
  • +MAX11615EWE+: FAQ
  • +MAX11616EEE+: FAQ
  • +MAX11617EWE+: FAQ
  • +MAX11625: FAQ
  • +MAX11629EEE+: FAQ
  • +MAX11645EWC+T: FAQ
  • +MAX11647EUA+: FAQ
  • +MAX11900: FAQ
  • MAX11905: FAQ
  • +MAX11905EVKIT#: FAQ
  • +MAX1202AEAP+: FAQ
  • +MAX1220: FAQ
  • +MAX1229: FAQ
  • +MAX1230BCEG+: FAQ
  • +MAX1231AEEG+: FAQ
  • +MAX1239EEE+: FAQ
  • +MAX1239KEEE+: FAQ
  • +MAX1239LEEE+: FAQ
  • +MAX1258: FAQ
  • +MAX1271ACNG+: FAQ
  • MAX1300: FAQ
  • +MAX1300BEUG+: FAQ
  • +MAX1301AEUP+: FAQ
  • +MAX13171: FAQ
  • MAX1343: FAQ
  • +MAX1343BETX+: FAQ
  • +MAX13487: FAQ
  • +MAX13488: FAQ
  • +MAX1379ATP+: FAQ
  • +MAX1383: FAQ
  • +MAX1447ECJ+: FAQ
  • MAX14571: FAQ
  • +MAX14571EUD+: FAQ
  • MAX14574EWL+: FAQ
  • +MAX14574EWL+T: FAQ
  • +MAX14578: FAQ
  • +MAX14579EEVKIT#: FAQ
  • +MAX14588ETE+T: FAQ
  • +MAX145ACPA+: FAQ
  • +MAX1474: FAQ
  • +MAX14783: FAQ
  • +MAX14805: FAQ
  • +MAX14807ECB+: FAQ
  • +MAX14900D: FAQ
  • +MAX1645AEEI+: FAQ
  • +MAX16600GGN+: FAQ
  • +MAX17823AGCB+: FAQ
  • MAX17823AGCB/V+: FAQ
  • +MAX17823AGCB/V+T: FAQ
  • +MAX17823GCB+: FAQ
  • +MAX182BEWI+T: FAQ
  • +MAX19777AZA+: FAQ
  • +MAX31865: FAQ
  • +MAX31865AAP+: FAQ
  • +Precision Technology Learning Modules
  • Programming FMC FRU ID EEPROM on Linux

AD7793: Current output compliance voltage and impedance

Q 

Here is another issue from the customer. They are using AD7793 , but found the
output of current source will change according to the load resistance. But this
only appears on the Gain setting =1 and 2 and the current source works well 
when the Gain>4.

           Below is the test result from the customer. Have ever heard about
this issue? Could you suggest why the output current is decreasing according to
the load. Thanks a lot.
    
---------------------------------------------------------------    
they are using RTD test circuit
Output of current source 210uA?sampling rate = 62.5Hz?bipolar mode?Channel 1 ?
continuous sampling ?single read
When the G=1
Load resistor        Output Reference Voltage (Iout X R)
0                                   2.32V
?=2.068K             2.32V
7.95K                 2.01V
?=11.43K            1.83V
When the load is smaller than 2.068K, the Reference voltage is stable. After
that, when the load is increasing the Reference voltage decrease. when the load
is bigger than 11.43K, the output is stable again no matter what the load
resistor value are.  When the Gain is 2, the issue still exist. But when G is
bigger than 4, the problem does not show.

 

A 

Is the load resistor connected between AIN+ and AIN-. What power supply voltage
is being used. The 210 uA excitation currents have an output compliance of 
AVDD - 0.65 V. So, the voltage at IOUT must be less than AVDD - 0.65V. If AVDD
= 5V, then the voltage at IOUT must be less than or equal to 4.35V.

The reference voltage equals 2.32V. So, at a gain of 1, the maximum resistance
between AIN+ and AIN- is (4.35V-2.32V)/210uA = 9.6K. The excitation current
value of 210uA is a typical value. The customer should allow some headroom as
the excitation current will vary from part to part.

As the gain increases, this resistance will be lower. So, at a gain of 4, for
example, the maximum resistance between AIN+ and AIN- is 2.4K.

Can you check with the customer to ensure that the output compliance spec is
being met.

Tags: ad7793
  • Share
  • History
  • More
  • Cancel
analog-devices logo

About Analog Devices

  • Who We Are
  • Careers
  • Newsroom
  • What We Do (Signals+)
  • Investor RelationsExternalLink
  • Quality & Reliability
  • Sales and Distribution
  • What's New on Analog.com
  • Contact Us

Find Help

  • Support
  • Resources
  • WikiExternalLink
  • Analog Dialogue

Get the Latest News

Stay up to date with our latest news and articles about Analog Devices' products, design tools, trainings, and events.

Sign Up Now
  • Instagram page
  • Twitter page
  • Linkedin page
  • Youtube page
  • Facebook
  • Legal and Risk
  • Accessibility
  • Privacy Policy
  • Privacy Settings
  • Cookie Settings
沪ICP备09046653号-1

©2025 Analog Devices, Inc. All Rights Reserved

analog-devices

About Analog Devices

Down Up
  • Who We Are
  • Careers
  • Newsroom
  • What We Do (Signals+)
  • Investor RelationsExternalLink
  • Quality & Reliability
  • Sales and Distribution
  • What's New on Analog.com
  • Contact Us

Find Help

Down Up
  • Support
  • Resources
  • WikiExternalLink
  • Analog Dialogue

Get the Latest News

Stay up to date with our latest news and articles about Analog Devices' products, design tools, trainings, and events.

Instagram page Facebook Twitter page Linkedin page Youtube page
  • Legal and Risk
  • Accessibility
  • Privacy Policy
  • Privacy Settings
  • Cookie Settings
沪ICP备09046653号-1

©2025 Analog Devices, Inc. All Rights Reserved