VBAT Backup Power Supply External battery

rohithinthingstech · ‎2024-10-27

I'm designing a custom PCB using the STM32F407G-DISC1 board as a reference, with the goal of meeting EMI/EMC standards. However, my design includes a VBAT connection from external battery that the reference board doesn't have. Can you advise on best practices for connecting the VBAT line to ensure proper operation and minimal noise?

In the attached schematic, I've connected VBAT to the battery cell and ground. Could you please review if this setup is correct for powering the circuit through VBAT? Also, is there anything else I should consider for stability or noise reduction and minimize the EMI/EMC issue?

SofLit · ‎2024-10-28

Hello @rohithinthingstech ,

Could you please tell why you are duplicating this tread from this one?

Please don't duplicate threads and keep the discussion in the same thread until you have new question that you need to open a new one for it

Thank you for your understanding.

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SofLit · ‎2024-10-28

And this is from STM3240G-EVAL schematics:

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rohithinthingstech · ‎2024-11-04

HOW TO TAKE RTC CONNECTION FROM V BAT CIRCUIT WHAT ARE THE REQUIREMENTS FOR THAT?CAN I GET ANY REFERENCE CIRCUIT?

SofLit · ‎2024-11-04

Already provided you a design guide from STM3240G-EVAL schematics:

https://www.st.com/resource/en/user_manual/um1461-stm3240geval-evaluation-board-stmicroelectronics.pdf / page 46:

Here it's a jumper in your HW you can hardwire it directly to VBAT pin.

Hope that answers your question.

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