Hi everyone,
We have been burning MAX9814 AGCs for the last couple of weeks. I have two eval boards of this IC and they work fine, no problems. We did our own PCB and we've been struggling with this IC.
Schematic is representative of what is actually on the board, we took a blank board where just the IC and its supporting circuitry were attached.
Assembly process:
The IC was put on a board by hands and great care was taken to not exceed max temperature of reflow, we've used leaded solder and once it reached melting temp, we did not expose it for more than 5-10 seconds. Ground pad was soldered as well. This is what it looks like when assembled. Pins 9 and 10 needed to be connected because there was a mistake in the schematic (corrected above).
The setup:
When first powered on, the IC draws ~4.19 mA of current, supplied by benchtop power supply. A signal generator is set for 100 mVpp 1000 Hz sine wave with no offset. Oscilloscope is attached at the other end of cap connected to pin 6, AC coupled with 1 MEG probe.
Failure mode:
Sometimes, the circuit works exactly as expected for several hours, then goes into failure mode, other times, it starts to fail on the first power on. When circuit works, it amplifies When failing, the current draw increases to 5 mA, then 8 mA, then drops back to 4 mA, oscillating (albeit without known period) between 4 mA to 10 mA until it stabilizes around ~15 mA. The moment the current starts exceeding 4 mA, the gain starts to compress and, until at some point it goes to 0, the output of the IC is floating.
Questions for Analog:
1. Is it possible to get in touch with someone who can help me troubleshoot this IC?
2. The ICs that we've ordered have "BEM" label on them, while ones attached to eval board have "NDO" on them. What's the difference?
3. Could you please provide us with Gerber/Altium files for the IC eval board? We know that your eval boards work, we want to find out how is our layout different
