Aurox TC3xx safety manual

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BKaufmann
Level 1
Level 1
First question asked Welcome!

Hi all,

There is the section 3.3.2 External Voltage Supply sections inside the safety manual and we are a bit confused abot the requirement

"An external device shall supervise the supply voltage of the MCU and in case of an overvoltage condition is
detected, the system shall disable the supply voltage of the MCU. A deviation above the specified maximum
admitted voltage, can lead to permanent failures and physical damage to the device. "

-->

"It is assumed that the system detects and disables the external voltage
supplies VEXT and VEVRSB of the MCU in case of an over-voltage condition with
the continuous monitoring of the external voltage supplies of the MCU."

Is there really an external deactivation mechanism needed which deactivates the power supply or is a supply which is robust enough sufficent (for an ASIL B application). There is also the SM[HW]:PMS:VEXT_MONITOR mentioned in your safety manual which seems to monitor also VEXT. 

Beside of this is there the question on our side why the internal mechanism are sufficient for VDD but not for VEXT or is there also an external monitor/deactivation mechanism needed for VDD which is not mentioned in the referenced section above.

 

Thanks for your help

 

best regards,

Björn Kaufmann

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1 Solution
Di_W
Moderator
Moderator
Moderator
500 solutions authored 1000 replies posted 250 solutions authored

Q:Is there really an external deactivation mechanism needed which deactivates the power supply or is a supply which is robust enough sufficent (for an ASIL B application). There is also the SM[HW]:PMS:VEXT_MONITOR mentioned in your safety manual which seems to monitor also VEXT.

A:You could refer to OPTIREG PMIC TLF35584, https://www.infineon.com/dgdl/Infineon-TLF35584QV-ProductOverview-DataSheet-v01_00-EN.pdf?fileId=554...

The TC3xx Safety Manual already described it is assumed that the system detects and disables the external VEXT and VEVRSB of the MCU in case of over-voltage condition and with continuous monitoring of the external voltage supplies of the MCU.

The PMS module has a primary and a secondary monitor, both monitors VEXT, you can refer to 11.2.2.5 AURIXTC3XX_um_part1_v2.0.pdf. However VEXT monitor is an internal safety machanism which cannot replace the system level hardware requirements - EXTERNAL VOLTAGE SUPPLY -ESM[HW]:PMS:VEXT_VEVRSB_OVERVOLTAGE


Q:Beside of this is there the question on our side why the internal mechanism are sufficient for VDD but not for VEXT or

A: VDD is different, because which is gernerally supplied by EVRC which is an internal voltage supply. Please refer to Table 13-1 Supply Mode and Topology selection in AURIXTC3XX_ts_V1.3.0.pdf.

Q:is there also an external monitor/deactivation mechanism needed for VDD which is not mentioned in the referenced section above.

A: No.

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1 Reply
Di_W
Moderator
Moderator
Moderator
500 solutions authored 1000 replies posted 250 solutions authored

Q:Is there really an external deactivation mechanism needed which deactivates the power supply or is a supply which is robust enough sufficent (for an ASIL B application). There is also the SM[HW]:PMS:VEXT_MONITOR mentioned in your safety manual which seems to monitor also VEXT.

A:You could refer to OPTIREG PMIC TLF35584, https://www.infineon.com/dgdl/Infineon-TLF35584QV-ProductOverview-DataSheet-v01_00-EN.pdf?fileId=554...

The TC3xx Safety Manual already described it is assumed that the system detects and disables the external VEXT and VEVRSB of the MCU in case of over-voltage condition and with continuous monitoring of the external voltage supplies of the MCU.

The PMS module has a primary and a secondary monitor, both monitors VEXT, you can refer to 11.2.2.5 AURIXTC3XX_um_part1_v2.0.pdf. However VEXT monitor is an internal safety machanism which cannot replace the system level hardware requirements - EXTERNAL VOLTAGE SUPPLY -ESM[HW]:PMS:VEXT_VEVRSB_OVERVOLTAGE


Q:Beside of this is there the question on our side why the internal mechanism are sufficient for VDD but not for VEXT or

A: VDD is different, because which is gernerally supplied by EVRC which is an internal voltage supply. Please refer to Table 13-1 Supply Mode and Topology selection in AURIXTC3XX_ts_V1.3.0.pdf.

Q:is there also an external monitor/deactivation mechanism needed for VDD which is not mentioned in the referenced section above.

A: No.

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