While working towards finding a root cause for why 6 - TAS1519 parts exhibit an intermittency in output audio, colleagues concluded it was not due to the solder stencil, i.e., the amount of solder deposited under the TAS1519. However, they determined that if they decrease the OSC RES value from 18.2k to 16k, then the intermittent audio issue disappeared. If they increased the resistor value to 20k, then there was no amount of probing to the part or trace between the OSC RES and the IC that would cause the audio to be present.
Is there is a tradeoff between the OSC RES value and the performance of the power amplifier. Does 18.2k cause the power amplifier to operate in the sweet spot? What are the tradeoffs with value?
We likely will not change the BOM for 6 parts out of hundreds manufactured, but it would be good to know the relationship between the OSC RES value and IC performance. The parts have worked for years without any issue. I believed the lack of solder under that TAS1519 resulted in a bad ground, and the touching of the hot end of the resistor, touching near the OSC pin, or touching the trace between the IC and resistor essentially jump started the oscillator. Since I don’t know the internal circuitry, I can’t be certain my theory was correct.
Any insights are appreciated.
Regards,
John
