topic Re: S32K148 RTC external power supply in S32K

S32K148 RTC external power supply

siva280386 — Thu, 23 Mar 2023 12:34:56 GMT

Hi NXP Team,

In S32K148 Micro, we understand that the RTC module is active in all low power modes. In Our Project , we are planning to remove the power completely to the micro to reduce the overall control board power consumption. Is there possibility a possibility to provide power source to RTC module externally , to let this run still and when the MCU is powered up back, we still see the RTC timer running to know the sleep time of our control system. I remember some high end micros in NXP support different power supply pins to different modules of the micro controller , like ADC , RTC...

We also read that RTC registers get reset on MCU power on reset. how does this work if incase there is an external power supply support?

Thanks,
Siva

Re: S32K148 RTC external power supply

VaneB — Thu, 23 Mar 2023 23:10:48 GMT

Hi @siva280386

The S32K1 family does not have an external power pin that allows you to keep the RTC active.

This family only has one power domain, VDD (3.3v or 5v).

B.R.

VaneB

Re: S32K148 RTC external power supply

abdullah45 — Sun, 26 Mar 2023 08:33:23 GMT

Hi @ VaneB

Please explain if there is an input pin for the VDD supply.

B.R.

Re: S32K148 RTC external power supply

VaneB — Mon, 27 Mar 2023 18:49:21 GMT

Hi @abdullah45

I suggest you take a look at Hardware Design Guidelines for S32K1xx.