REGISTER | LOGIN
Breaking News
Comments
Newest First | Oldest First | Threaded View
BicycleBill
User Rank
Author
re: Calibrate a power supply with a digital potentiometer
BicycleBill   2/17/2012 9:18:34 PM
NO RATINGS
Certainly, it's not a solution to every design situation, but it gives you new degrees of freedom and flexibility--and along with that, comes responsibility!

sharps_eng
User Rank
Author
re: Calibrate a power supply with a digital potentiometer
sharps_eng   2/17/2012 8:05:21 PM
NO RATINGS
Agreed - replacing a hardware device with a digital pot which contains a bunch of registers, non-volatile or not, increases the state complexity of the system. It may make a better system, but it makes a different system which needs to be tested differently. The ESD /EMI compliance issue is just one manifestation of this. Also: make sure you choose the right version of the pot chip, you don't want your systems to be powered up first time, set at the wrong end of the pot when you want it to be set in the middle.

stricula
User Rank
Author
re: Calibrate a power supply with a digital potentiometer
stricula   2/16/2012 8:54:31 PM
NO RATINGS
Had a colleague try this in a design. Worked well until ESD testing. Just wanted to present that potential pitfall. Ended up re-purposing that digital pot control output to PWM into an RC filter. The RC filter output was connected to a resistor which went into the feedback node of the regulator. The micro was always reading the voltage out of the regulator. It was an obvious solution once realized that the feedback node is ideally a fixed voltage; lower value than specified = more power commanded out. Makes for an easily configurable and adjustable power supply.



Most Recent Comments
Like Us on Facebook
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Martin Rowe

Test Tool Finds Ethernet Wiring Errors
Martin Rowe
Post a comment
When my house was renovated several years ago, I had the electrician install network outlets in numerous places, then run the LAN cables to a wiring closet. But he didn't document the ends ...

Martin Rowe

Local Electronics Store Supplies Engineers and Hobbyists
Martin Rowe
5 comments
Rochester, N.Y. — Tucked away in this western New York city known for its optics is Goldcrest Electronics, a local store that's supplied businesses and individuals with electronic ...

Martin Rowe

How to Transform a Technology University (Book Review)
Martin Rowe
1 Comment
The Presiding Genius of the Place by Alison Chisolm. WPI, Worcester, Mass., 234 pp., 2016. Engineers love to discuss, and often criticize, engineering education. They often claim ...

Max Maxfield

Aloha from EEWeb
Max Maxfield
Post a comment
Just a few minutes ago as I pen these words, I posted this blog about this month's Cartoon Punchline Competition over on EEWeb.com.