Tool/software:
We recently discovered a manufacturing issue on one of our RS-485 boards, where the SN65176B transceiver was inadvertently populated and powered from a 3.3 V rail instead of the intended 5 V.
Despite being outside the specified 4.75 V – 5.25 V operating range, initial functional tests indicate that communication appears to function correctly at room temperature. However, we are concerned about the long-term reliability and possible latent degradation of these devices due to prolonged undervoltage operation.
Could you please clarify:
1. Whether continuous operation at 3.3 V may cause accelerated wear, latch-up susceptibility, or threshold drift in the SN65176’s driver/receiver circuits.
2. If there are any internal protection or bias networks that might behave unpredictably under such undervoltage conditions.
3. Whether TI has any empirical or qualification data on devices operated below the minimum VCC rating (e.g., failure rates, parameter drifts, or reliability test results).
Our goal is to assess the reliability of these units. Any insights on electrical margin, long-term degradation mechanisms, or risk of field failure at 3.3 V operation would be greatly appreciated.
