Power ManagementのトピックRe: Clarifications required For SBC INTB behavior during Fault Condition

Clarifications required For SBC INTB behavior during Fault Condition

Sivahari — Tue, 26 Aug 2025 06:44:22 GMT

Hi NXP,

I am using SBC MFS2613AMDA6 IC.

I have got clarity about INTB purpose and also understood INTB will provide 25us(Default configuration) low pulse when any OV, UV or Watchdog Fault has occurred.

If SBC has incurred a non-recoverable Fault, then will thew INTB provide a low pulse only once or will there be a periodic pulse distributed with specific time intervals.

Let us consider the SBC INTB pulse duration configured as 25us, Watchdog period configured as 16ms, all VMON Failsafe reaction configured as "NO EFFECT On RSTB and FS0B" and FS INTB Register Configured all as unmasked.

Q1. How often INTB provide low pulse when there is a continuous watchdog error (either Bad data/Bad timing)?

Q1. How often INTB provide low pulse when there is a continuous VMON Fault (either overvoltage/undervoltage)?

Thanks for support.

Re: Clarifications required For SBC INTB behavior during Fault Condition

guoweisun — Wed, 27 Aug 2025 09:29:30 GMT

Q1. How often INTB provide low pulse when there is a continuous VMON Fault (either overvoltage/undervoltage)?

[gw]I have EVB but can't test the WD related function, for this question I short LDO1 all the time the INTB behavior same with short LDO1 one time in the INIT phase-around 2ms INTB provide low pulse.

Re: Clarifications required For SBC INTB behavior during Fault Condition

Sivahari — Thu, 28 Aug 2025 05:15:50 GMT

Hi Gouweisun,

Do you meant to say that SBC INTB providing continuous low pulse(25us) for every 2ms time interval when there is always a LDO1 undervoltage fault and also in case of single time LDO1 undervoltage fault occurs?

Thanks for Support.

Re: Clarifications required For SBC INTB behavior during Fault Condition

ErikaC — Thu, 28 Aug 2025 16:21:01 GMT

Hello,

Q1. How often INTB provide low pulse when there is a continuous watchdog error (either Bad data/Bad timing)?

Watchdog errors, whether due to bad data or bad timing, are classified as fail-safe interrupts according to Table 182 of the datasheet. This means they will trigger a pulse on the INTB pin even if the corresponding interrupt flag is already set.

A pulse on INTB is generated each time a valid interrupt occurs, and in this case, watchdog data errors are considered valid. Therefore, INTB will generate a low pulse every 16 ms, corresponding to each failed watchdog refresh cycle.

Hope this helps.

Re: Clarifications required For SBC INTB behavior during Fault Condition

guoweisun — Wed, 03 Sep 2025 00:28:24 GMT

Yes,that's my test result I forgot to catch the waveform,if still have questions please let me know!