VBAT pin on STM32F070

Muhammad Moiz khan · ‎2017-02-22

Posted on February 22, 2017 at 09:58

Hello,

These days I was working on the internal RTC of STM32F070, I looked at the examples majority are those in which STM32 micro controller possesses VBAT pin as opposed to my STM32F070 doesn't have that pin, I looked at the datasheet to see whether any other pin maybe different name with similar functionality for RTC but unable to find. Any help in this regard would highly appreciated.

Regards,

Muhammad Moiz khan.

#clive1

T J · ‎2017-02-22

Posted on February 22, 2017 at 12:28

Yes, there is no VBat pin ton this '070 processor.

unusual.

the '072 has it...

waclawek.jan · ‎2017-02-22

Posted on February 22, 2017 at 12:32

That's not unusual but intentional. The 'Fxx0 are 'Value Line', ie. deliberately stripped-down versions of 'F0x1/'F0x2.

JW

Muhammad Moiz khan · ‎2017-02-26

Posted on February 27, 2017 at 06:02

Thanks for the response, need ask so what's the point of adding RTC on '070' uC. Do I have to add external circuitry? less practical indeed.

T J · ‎2017-02-26

Posted on February 27, 2017 at 06:53

If you are connected through some network, even Canbus, you can update the RTC value from the host...

but still keep a relatively accurate time without updating every hour.

However, if the power goes down and the host does not come back up, then you need the battery pin to maintain your local RTC.

waclawek.jan · ‎2017-02-27

Posted on February 27, 2017 at 09:30

Good question... ;)

Jan