Question Question on AD7691: What should be Vref to convert of the maximal number of bits a difference between two signals which a little from each other differ? For example, Vin + = 4,5V, Vin-= 4,49V. Answer As the absolute input range max is =Vref and your signal max is = 4.5volts, then you can't use a lower ref value less than 4.5volts. So assuming you are using supplies of 5volts, you should take your Vref from your 5volt supply and use a common mode of 2.5volts Vref/2. The main requirement of Vref is that it should be a low impedance source with recommended decoupling to act as a reservoir of charge. Driving the part differentially is important in order to get performance.

English

Forums
Popular Forums
Product Forums
View All
Application Forums
Design Center Forums
Learn
Highlighted Webinar

Fast-Track Certification: Leveraging IC Safety App Notes for Functional Safety Designs
Stop guessing, start certifying. Learn how to use IC safety application notes to streamline your FMEDA and meet IEC 61508 and ISO 13849 standards with...
Places
Libraries
Upcoming Learning & Events
View All Webinars
Community Hub
Challenge Yourself!
View All
What's Brewing
View All
Places
Resources
View All
ContentZone
Visit ContentZone
Search content by industry or technology.

Blogs

Technical Articles

Tutorials

Videos

Webinars

Your ADI content all in one place.
View ContentZone
The Latest Read

Clock Tree Design and Why “PLL Locked” Is Not Enough
In high-performance RF systems, clocking architecture is a foundational element that directly governs signal integrity, synchronization, and overall system...

New Release

Signal Chain Designer: DC Error Simulation
This video covers the DC error calculation capabilities of Signal Chain Designer. DC error is unique in that often requires calibration and has so many...

Recent Technical Insights

Improving Industrial Functional Safety Compliance with High Performance Supervisory CircuitsPart 5: Sequencers Eliminate Systematic Failures
This article shifts focus from managing the quantitative metrics of functional safety toward mastering the qualitative yet equally critical challenge:...

EngineerZone

Precision ADCs

Log In

User
Site
Search

OR

Ask a Question

Data Converters

Precision ADCs

Documents AD7691: FAQ

Q&A
File Uploads
FAQs/Docs
Help Articles
Members
Tags
Cancel

Products Mentioned

AD7691 Production
The AD7691 is an 18-bit, charge redistribution, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD...
Datasheet
AD7691 on Analog.com