Running RTC independently via coin battery?

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Anonymous
Not applicable

Hello,

   

I am using a PSOC5LP and I have some questions on the implementation of sleep mode and running RTC independently. 

   

I want to turnoff the main power of the MCU and run the RTC independently via a coin battery in sleep mode. Is it possible? 

   

In other words, the coin battery is always connected to Vbat and when the main power supply of the mcu is turneddown, can the coin battery run RTC in sleep mode as an independent block without the need of the connection to main power supply?

   

 

   

Thanks.

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4 Replies
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Plain answer: No.

   

You may set the Psoc5 into deep sleep and wake it up every second. Then maintain the RTC and go to sleep again.

   

 

   

Bob

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Anonymous
Not applicable
        Sorry, I didn't understand your answer for my question. Can I not power off the mcu and just run RTC via an external coin battery?   
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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Short answer: No

   

Reason: The RTC is pure software, so MCU is needed.

   

 

   

Bob

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MiKO_283856
Level 4
Level 4
50 replies posted 25 replies posted 10 replies posted

This RTC is a real pain!

   

The fact you should keep the MCU alive, even in sleep mode, in order to wake it up every second does not add ease to the design and the consumption, believe me. I have decided not to repeat this experience, never.

   

I strongly suggest you to shift to an external RTC fed by its own  cell, you add 1 more component to your design, but you go quiet.

   

My personal thought.

   

 

   

Michel

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