DS3231 on a Due

Can I supply a DS3231 with 5v when on a Due? I am looking at moving a project from Mega to Due as I need more speed. I understand that my DS3231 module can run a 3.3v but I have one on a little shield that gets 5v from the pins adjacent to pin 22. My concern is the output of the DS3231 to pins 20,21 if I continue to use 5v.

Vin can be Vcc + 0.3V Max on a DS3231 per the datasheet. So 3.8V Max if Vcc = 3.3V, and 5.5V Max if Vcc = 5V.

Nick_Pyner: I understand that my DS3231 module can run a 3.3v but I have one on a little shield that gets 5v from the pins adjacent to pin 22.

OK, so you know how you can do it correctly (operate DS3231 with 3.3V), but you want to do it different and use the wrong voltage?

In that case: Use level shifters to shift the voltage levels on the signal pins!

Are there any more I2C devices on your project? If not, you've probably pulled the bus up to 3.3V.

jurs: OK, so you know how you can do it correctly (operate DS3231 with 3.3V), but you want to do it different and use the wrong voltage?

No, I should have been more specific. I said this is a module, and I now see is a ZS-042. Five volts is not the wrong voltage, indeed I assume it is very much the right voltage in view of the rechargeable 3.6v battery on board.

I have now found a wiring diagram but I don't see any level shifters, and it is going to be a bit of a struggle to add them. I don't know if both pins require shifters and I guess scl doesn't.

liudr: Are there any more I2C devices on your project?

I would normally make provision for an i2c 4x20 LCD, but probably not in this case.