DS1307 Logic voltage?

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hans_landa
 
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DS1307 Logic voltage?

Post by hans_landa »

Trying to figure out if I can use the DS1307 on my Portenta (a pricey board with 4v max LL). Product page states this:

"5V power to work (although we've used it with 5V power and 3.3V logic successfully)"

"If you do not need a DS1307, or you need a 3.3V-power/logic capable RTC please check out our affordable PCF8523 RTC breakout"

In my humble opinion these two statements seems to contradict one another so I am just trying to figure out for sure, does the DS1307 use 5v or 3.3 logic? Rather not fry this thing.

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dastels
 
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Re: DS1307 Logic voltage?

Post by dastels »

Looking at the DS1307 chip datasheet, Vcc is 5v but 3.3v logic will work. However the onboard pullups on SDA and SCL are to Vcc which is 5v. The DS3231 may be a better choice for you. https://learn.adafruit.com/adafruit-ds3 ... ut/pinouts.

Dave

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hans_landa
 
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Re: DS1307 Logic voltage?

Post by hans_landa »

Thank you Dave, rather be safe than sorry on this one.

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