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Can MMPF0100F0AEP VGEN6 supplies to VIN1?

Question asked by Satoshi Shimoda on Jun 30, 2015
Latest reply on Jul 1, 2015 by Satoshi Shimoda

Hi community,


I have a question about MMPF100F0AEP.

Actually, our partner consider using MMPF0100F0AEP VGEN6 (3.3V) for VGEN1 supply.

I think VGEN6 output voltage accuracy (+-3%) is good to supply VGEN1 (up to 3.40V input) since 3.3V * 103% = 3.399V.

And I think there is no timing issue since VGEN6 turn-on time is up to 500 us, it is sufficient to supply VGEN1 (SEQ=9) from VGEN6 (SEQ=8).


However, I have concern about start-up overshoot.

VGEN6's start-up overshoot(max) is 2.0%, so in worst case, VGEN6 voltage will be 3.3V * 103%(voltage accuracy) * 102% (start-up overshoot) = 3.47V.

It exceeds VIN1 input voltage (up to 3.4V).


On the other hand, in the case of SW4 which is used for VIN1 supply on SABRE-SD, it also exceeds VIN1 input voltage in worst case as following.

3.15V * 106% (in PWM mode) + 66mV (start-up overshoot) = 3.405V


So I'm confused by these calculation.




Can we use VGEN6 to supply VIN1?

How should we judge whether each MMPF0100F0AEP output can supply to VIN1 or not?



Best Regards,

Satoshi Shimoda