Analog measurements and switching power supply


I intended to use the beagle bone with a battery using a switching power regulator like this one:
Someone pointed out, that these kind of regulators could produce noise for my ADC measurements and for the used IMU-sensors (which are powered via the 3.3V supply from the BB).
I am not an electrical engineer, so maybe someone who is (or knows about these things :wink: ) could tell me, if it is a valid concern? Then I would probably have to use linear regulators which produce more heat dissipation.

Best regards,


It is a valid concern.


I see. Would linear regulators solve that problem?
As far as I understand their principle, there are no fast switching parts and the stability depends more on the load and it's variability?

They would be a better choice. Of course if your 5V supply is a switcher, that sort of defeats the purpose. They both should be a linear power supply.


I am sorry, I forgot to mention that I want to power the BB from battery. As there are no 5 V batteries (to my knowledge) and according to another thread higher voltages could produce smoke signals, I thought using 6-7 V and regulate it down to 5V.
Then I guess the linear regulator would be the way to go? Long time efficiency is not the main concern anyway.

Best regards,




Let me see if I can give you an answer that is actually helpful. No you
don't want to use that supply. Just looking at it I can tell that it
will be noisy. plus it's expensive. Making the assumption that IMU is
Inertial Measurement Unit, I'm further assuming this is going on a model

What you need is two regulators, one for 5 volts and one for 3.3. Don't
try to rob the Bone of any power. It can be done but only after careful

Here are the details.

Power source: 2 LiPo batteries for 7.2 volts.

1 LM7805 5 volt voltage regulator, digikey #LM340T-5.0/NOPB-ND $1.40
1 LM3940IT-3.3/NOPB 3.3 volt voltage regulator. $1.75
2 clip on heat sinks. digikey #HS111-ND $0.38
4 1uF 50volt film capacitors, digikey #P4675-ND $0.68

Connection is as follows:

                                 Regulator LM7805
LiPo positive ----------------+-----+ +------+---------
                              > >----+----| |
                              > > >
                             --- | ---
                    1uF cap --- | --- 1uF cap


Ok. Thank you very much. I now got most of the parts from or electronics department. I only used some different capacitor sizes.