I was attempting to create my own breakout board for the AD8232 using the SparkFun board as a reference to help design my own. One part of the schematic that caught my attention was the 2 DNP resistors drawn on, which I can’t seem to figure out the purpose of, do they serve any purpose? Is there any case where they would need to be connected?
Hello ash_b,
There could be multiple reasons. It looks like “R20” connected to AC/DC pin would pull that pin high if it were connected. “R18” would interact with the SW pin. I’m not able to say what features these changes would make for that specific IC. The [datasheet would give you a better idea what those choices would do for it’s operation.](https://cdn.sparkfun.com/datasheets/Sensors/Biometric/AD8232.pdf)