Hello E2E Experts,
Good day.
We are losing several hundred dollars a month of final product due to failures in part LMC7660. We are using the part well within the voltage spec of the part (3.5 VDC" and in a "N+1" configuration but still the parts appears to be failing internally at switch S2 in a significant fraction of finished goods. The data sheet refers to "destructive latch up" but there is only so much control a designer has, this design has no other logic chips that are failing.
I’m starting to suspect that the capacitor values being loaded on our boards are at C131 (below) are inconsistent across builds and this may be the reason the charge pumps don’t function. I would like your feedback on whether the circuit snippet below follows your recommendation for a “N+1” redundant configuration. We don’t need twice the current but I believe diodes D505 and D506 provide failure isolation.
Regards,
CSC
