Design Con 2015
Breaking News
Comments
Newest First | Oldest First | Threaded View
BicycleBill
User Rank
Rookie
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
Rookie
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
Rookie
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
Top Comments of the Week
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Max's BADASS Display: A Comedy of Errors
Max Maxfield
5 comments
Good grief -- where does the time go? I first determined to build my Bodacious Acoustic Diagnostic Astoundingly Superior Spectromatic (BADASS) display way back in the mists of time we used ...

<b><a href=Betajet">

The Circle – The Future's Imperfect in the Present Tense
Betajet
5 comments
The Circle, a satirical, dystopian novel published in 2013 by San Francisco-based writer Dave Eggers, is about a large, very powerful technology company that combines aspects of Google, ...

Martin Rowe

Make This Engineering Museum a Reality
Martin Rowe
Post a comment
Vincent Valentine is a man on a mission. He wants to make the first house to ever have a telephone into a telephone museum. Without help, it may not happen.

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
16 comments
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...