Waterme11on
Active member
Hey guys,
I've been developing my own pcb that is a circuit comprising of the Teensy 3.2, Pjrc Prop shield, and Sparkfun 5v/1A boost converter (to power the Audio amplifier - LM48310).
I'm using the Teensy audio library to send audio to a single 4 Ohm speaker.
The problem I'm having is with my custom pcb, when i go over 0.7 gain with a saw wave at 160hz, the audio amplifier (or potentially the capacitors connected to it) shorts out and completely breaks. The circuit will only function again after i disconnect the broken amplifier , and until then the entire circuit is unresponsive. Everything works perfectly underneath a gain of 0.8, I have also tested full volume on the premade boards and it works without issue.
When the amp died after going up to 0.8 gain, I actually saw the board spark out of the corner of my eye , but I'm not sure exactly where the spark was, other that it was in the area of the audio amplifier.
The only thing I can think of is that my capacitors are placed incorrectly, and running high power through them is causing a short to happen through the air.
I'm attaching screenshots of my pcb design and schematic, if anyone can comment that would be an amazing help!
The board is 2 layers, with a ground pour on the bottom. The audio amplifier has a heat dissipating ground pour on the top layer too.
I've been developing my own pcb that is a circuit comprising of the Teensy 3.2, Pjrc Prop shield, and Sparkfun 5v/1A boost converter (to power the Audio amplifier - LM48310).
I'm using the Teensy audio library to send audio to a single 4 Ohm speaker.
The problem I'm having is with my custom pcb, when i go over 0.7 gain with a saw wave at 160hz, the audio amplifier (or potentially the capacitors connected to it) shorts out and completely breaks. The circuit will only function again after i disconnect the broken amplifier , and until then the entire circuit is unresponsive. Everything works perfectly underneath a gain of 0.8, I have also tested full volume on the premade boards and it works without issue.
When the amp died after going up to 0.8 gain, I actually saw the board spark out of the corner of my eye , but I'm not sure exactly where the spark was, other that it was in the area of the audio amplifier.
The only thing I can think of is that my capacitors are placed incorrectly, and running high power through them is causing a short to happen through the air.
I'm attaching screenshots of my pcb design and schematic, if anyone can comment that would be an amazing help!
The board is 2 layers, with a ground pour on the bottom. The audio amplifier has a heat dissipating ground pour on the top layer too.