Failing 4KV ESD Contact Discharge #3

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opened 2021-03-11 17:38:19 +00:00 by allspice-kyle · 0 comments

Disclaimer: The following data is fictional and does not represent real-world performance of the Archimajor Rambo Board

Summary

v0.4 of the Alpha main board fails required spec: 4KV contact discharge at endstop inputs.

Failure Mode(s): 10/10 cases SAM3X processor enters reset condition. 2/10 cases, memory is corrupted.




[Left] Relevant Schematic

Test setup

TBD

Analysis

Atmel SAM3X (pg. 1378) specifies max VDDIO operating voltage of 4.0V. Contact ESD discharge with no alternate ground path exceeds this value with significant energy content.

Simulation Results

The following simulation shows the circuit response to 4K discharge with no ESD protection.
Endstop Circuit

ESD Base
The input stimulus shown at 4KV

ESD Base
VDDIO reaching 65V at the SAM3X chip clearly exceeds voltage specification of 4.0V

*Disclaimer: The following data is fictional and does not represent real-world performance of the Archimajor Rambo Board* ## Summary !thumbnail[Endstops](EndStops.SchDoc){ commit="9f594c695a488ea6b576d21e42408135cf2fb548" view-coords="9,62,40,103" href="https://hub.allspice.io/AllSpice/Archimajor/src/commit/9f594c695a488ea6b576d21e42408135cf2fb548/EndStops.SchDoc" aspect-ratio="1.501"} v0.4 of the Alpha main board fails required spec: 4KV contact discharge at endstop inputs. Failure Mode(s): 10/10 cases SAM3X processor enters reset condition. 2/10 cases, memory is corrupted. \ \ \ \ [Left] Relevant Schematic ## Test setup TBD ## Analysis Atmel [SAM3X](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-11057-32-bit-Cortex-M3-Microcontroller-SAM3X-SAM3A_Datasheet.pdf) (pg. 1378) specifies max VDDIO operating voltage of **4.0V**. Contact ESD discharge with no alternate ground path exceeds this value with significant energy content. ## Simulation Results The following simulation shows the circuit response to 4K discharge with no ESD protection. ![Endstop Circuit](https://hub.allspice.io/attachments/37b73d49-9763-430c-8ef2-8d7146fbcf4c "Endstop Circuit") ![ESD Base](https://raw.githubusercontent.com/AllSpiceIO/Archimajor/7ce1854e2ecebede7c92cea9e21a71155f8da14a/Simulation/ESD/Endstops_ESD.svg "ESD Endstop Base Condition") The input stimulus shown at 4KV ![ESD Base](https://raw.githubusercontent.com/AllSpiceIO/Archimajor/7ce1854e2ecebede7c92cea9e21a71155f8da14a/Simulation/ESD/Endstops_ESD_SAM3X.svg "ESD Endstop Base Condition @ SAM3X") VDDIO reaching 65V at the SAM3X chip clearly exceeds voltage specification of 4.0V
allspice-kyle added the
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bug
labels 2021-03-11 17:38:19 +00:00
allspice-kyle was assigned by valentina 2021-03-11 17:40:00 +00:00
allspice-kyle was unassigned by valentina 2021-03-11 17:40:10 +00:00
allspice-kyle was assigned by valentina 2021-03-11 17:40:13 +00:00
H1-z0mb13 added a new dependency 2021-07-30 09:23:28 +00:00
H1-z0mb13 removed a dependency 2021-08-04 14:48:48 +00:00
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