Thanks Paul, I need to take back the statement that we read device ID A0 on the earlier devices, it was A1 there as well (however, we still can distinguish the devices by the marking on the package) Right now we are just using override mode. No oscillations occur. I even placed a new device on a known good older PCB (where I removed the earlier device) and the behavior is the same: earlier devices in override mode: measured voltage is with 5mV of the set voltage new devices in override mode: measured voltage is up to 50mV lower (most cases) and on several more rare occasions up to 100mV higher. This is device dependent but within one device it is repeatably stable. From a blackbox perspective I would guess that the accuracy of the reference voltage is the root cause. Tests were done mostly with a target setting of 1.96V. I haven't further checked but a quick test at 2.5V seemed to increase the delta between set and measured voltaged. I can check that on monday. Note that measurements are done at pins 10 & 14, so directly at the DAC's with the outputs disabled. In the mean time we asked our pcb manufactor to get lot codes etc from their supplier. Br, Jan
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