MPL3115A2 3.3 vs 5v rails
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- mrbandit_stg
- Posts: 11
- Joined: Mon Oct 04, 2021 5:03 pm
MPL3115A2 3.3 vs 5v rails
It appears that if I connect the 3.3 pin to a 3.3v source, but NOT connect the 5V, the I2C lines should operate at 3.3v, because the output of the FETs are not being pulled to 5V. The FETS should conduct because the baes is pulled to 3.3v, therefore the FET is logically just a wire,
Is this correct? I need 3.3v, and would hate having to put a 5v power on the boards, along with the voltage level shifters.
Please advise ... yours ..., bandit
- adafruit_support_carter
- Posts: 29150
- Joined: Tue Nov 29, 2016 2:45 pm
Re: MPL3115A2 3.3 vs 5v rails
The 3vo pin is the power *output*. Do not apply power there. Power should be applied to the Vin pin.
For 3.3V usage, just power with 3.3V at the Vin pin.
https://learn.adafruit.com/using-mpl311 ... -2982486-2
For 3.3V usage, just power with 3.3V at the Vin pin.
https://learn.adafruit.com/using-mpl311 ... -2982486-2
- mrbandit_stg
- Posts: 11
- Joined: Mon Oct 04, 2021 5:03 pm
Re: MPL3115A2 3.3 vs 5v rails
thanks! works like a champ!
Please be positive and constructive with your questions and comments.