QWIIC Speaker Amp Schematic

Qwiic System
1

Please advise the values of L1-L4 as shown on the SparkFun Qwiic Speaker Amp Schematic - DEV-20690 v10. The values given of “220Ω” don’t make sense. Schematic excerpt attached.

Thanks!

Schematic L1-L4.png
Schematic L1-L4.png910×804 29.1 KB

2

Hi,

They are BLM21PG221SN1D ferrite bead filters: 220 Ohms at 100MHz.

Cheers,

Paul

3

This is the equivalent circuit, suggesting the output has a 723kHz low pass filter

BLM21PG221SN1D ferrite bead.png

Class D amplifiers require expertise! A speaker acts as a low pass filter. An oscilloscope is a poor choice to test the amplifier bandwidth without a better low pass filter.

Thanks!