using MMPF0100F6 as replacement for MMF0200F6

[max123]

Hi,

we use the MMPF0200 (OTP F6) in a custom design with a i.MX6 Solo. This board is in production.

Since the MMPF0200 is not available at the moment, I need to consider using the MMPF0100. The F6 OTP seems to be a suitable replacement.

In my design, all RSVD-pins are connected as suggested in the datasheet, therefore the Feedback- and switch-pins for SW1C and SW4 are unconnected.

The regulators are enabled in the OTP F6 of the MMPF0100.

Do I need do  generate a custom OTP for the MMPF0100NP, or is it possible to leave the regulators running?

[reyes]

Hi,

Since the extra regulators would be running in the MMPF0100, there would be an extra current consumption in the system. If this extra current consumption is not a critical problem for your application, then yes, you can use the OTP F6 preprogrammed version of the PMIC with the unused regulators unconnected but running without any problem.

[max123]

Thank you for your response!

I can live with an additional current consumption, as long as there are no thermal problems. My supply is generated with a switching regulator from a 24V supply and has enough reserves (at least 500mA).

I am a little concerned about the Behavior of the regulators with an open feedback loop. It would be a Problem, if the PMIC reports an error. The PMIC may even fail to start, since the output voltages of SW1C and SW4 will never be ok.

Is there any information available on the Behavior oft the MMPF0100 in this case?

[reyes]

Hi,

The recommended connections for Input, Output, and Feedback pins when SW1C and SW4 are unused on the MMPF0100 are as follow:

SWxCLX should be left floating

SWxCIN should be connected to VIN

SWxCFB should be left floating

You can find information on the application note AN4717: https://www.nxp.com/docs/en/application-note/AN4717.pdf

You should not have any thermal problems.

The feedback pin is internally connected to a comparator as you can see in figures 11 and 26 of the datasheet. Since the FB pin is floating, the comparator never enables the feedback signal to the to the feedback compensation loop.