PicoMite: driving a small speaker


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phil99

Guru

Joined: 11/02/2018
Location: Australia
Posts: 1892
Posted: 07:21am 25 Mar 2023      

"Will it work reliably on 3.3v and lower as the battery runs down a bit?"

The one I have does. It's blaring at me now at 2.1V (ok blaring is an exaggeration but it is still loud enough).

As the PWM is driving it into clipping anyway it does not need to have "headroom" voltage for linear operation.

After a bit more testing there is a rise in distortion as the voltage goes below 3.3V so the LM386 is not the best choice for battery operation.
It does however demonstrate that a linear amp will boost a PWM signal with acceptable results.

Tom, try the ones you have and see what happens.
Edited 2023-03-25 21:30 by phil99