i.MX ProcessorsのトピックRe: MMPF0100 backflow

MMPF0100 backflow

masato1212 — Thu, 07 Jan 2021 04:33:50 GMT

Hi community,

I am using MMPF0100 for PMIC when using i.MX6.
When powering off the VIN of the PMIC, there is a timing when the electric charge remains in the capacitor on the output side and Vin <Vout. Is this OK as a PMIC? Do I have to take any measures to prevent backflow?

Best regards,

Re: MMPF0100 backflow

nxf63675 — Thu, 07 Jan 2021 23:59:18 GMT

Hi Masato,

In which of the output you have these remain power? Because some outputs are Buck-boost and others LDO, if the remain power is on the Buck boost there should not be longer problem, if it is on the LDO could cause some damage on the PMIC.

Regards,

Israel H.

Re: MMPF0100 backflow

masato1212 — Fri, 08 Jan 2021 09:47:56 GMT

Hi Isreal H,

Thank you for your answer.
Buck-boost is not a problem, is it a problem with LDOs? Why is Buck-boost not a problem?
Now both Buck-boost and others LDOs have reverse voltage.
However, the reverse voltage is about 0.3 to 0.4V. Is it okay to think that there is no problem if the voltage is about this level because it is lower than the Vf of the internal FET?

Best regards,

masato

Re: MMPF0100 backflow

nxf63675 — Fri, 08 Jan 2021 19:25:15 GMT

Hi Masato,

I was thinking for a bigger reverse voltage, this is not a problem, as you already said it this voltage is lower that the internal FET, and for the question why the buck-boost is no a problem is because has some coils that help to prevent any damage on this, something that an LDO doesn't have.

Hope this help you.

Regards,

Israel H.