Design Log DEC 010 inc 14 deferred legacy probe access esd protection post prototype - thepinkmile/Enigma-NG GitHub Wiki

DEC-010 - INC-14 DEFERRED: Legacy Probe-Access ESD Protection (Post-Prototype)

• Status: Deferred - Accepted risk for prototype stage
• Date: 2025
• Category: Electrical
• Area: Historical Controller bring-up probe-access concept

Supersession note: Historical-only. See DEC-040 for the current rule that all Diagnostics Banks are removed from the active design specs and will only be reconsidered later during the coupon implementation review.

Decision

ESD protection on the historical probe-access concept is deferred to post-prototype evaluation. No TVS diodes or series resistors are added to those bring-up-only signals at this stage.

Rationale

• The probe-access concept was internal, accessed only by engineers with ESD precautions during development.
• Adding ESD protection to every bring-up-only signal adds cost, board space, and complexity before there is validated evidence that it is needed.
• Risk accepted for prototype: controlled lab environment, trained operators, no field exposure.

Post-Prototype Action Required

• During first prototype test phase, evaluate signal integrity and ESD sensitivity on any temporary bring-up probe lines.
• If any such lines are exposed to field conditions (e.g., external test connectors), add series 33Ω + TVS per line.
• Document findings and update this log with the final resolution.