Only a small number of PowerBoost boards make noise. I don't have specific numbers, but the number of people who've mentioned it here in the forums are well below 0.1% of the number we've sold.
For the boards that do whine, it's usually a side effect of the magnetic field generated in the power inductor. That generates physical forces just like in a motor, and the windings in any coil can move microscopic distances.
Usually the coil's physical resonant frequency is different enough from the electrical frequency that the flexing doesn't do anything noticable. If the ratio of the two frequencies happens to be close to an integer, you can get an audible resonance.
Filtering the output won't have any effect on the noise. They're different parts of the circuit.
PowerBoost 1000 whine/noise vs. ADC
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
-
adafruit_support_mike
- Posts: 66613
- Joined: Thu Feb 11, 2010 2:51 pm
Please be positive and constructive with your questions and comments.