Sensor Application Circuit and Arduino: Pullups? Capacitors?


I tried searching the forums for a similar question but was not able to find something that matched. This may be because I had a hard time formulating the search parameters so please forgive me if there are relevant discussions that I missed.

I am working with an Arduino Uno to control a humidity sensor from Honeywell. In the sensor's datasheet, the Typical Application Circuit indicates that the Vdd and Vss should have a 22uF capacitor between them and that both the SCL and SDA should have a 2.2kOhm pullup resistor. My question is whether the Arduino's internal pullups (and capacitance?) would be sufficient in this case or if I should be adding them into the circuit?

The component is quite sensitive and I only have a few so I wanted to get some input on the forum before jumping in. Would really appreciate any advice you can offer.

Hope for hear from you,
Yusif Nurizade

P.S. Here is a link to the sensor datasheet:

Internal pullups are only sufficient for 1 load located very nearby.
For any real load, use external pullups on the I2C pins.
2.2K is typical if pulled up to 3.3V
(requires turning off the Arduino internal pullups.)
4.7K is typical if pulled up to 5V.


Thank you for the reply. I'll incorporate the components indicated in the Typical Application Circuit.

I'm curious about turning off the internal pullups. The previous step for my project had me controlling a IC that already had the wiring done. I connected the power, ground and I2C lines and controlled it with no problem. How much damage am I causing by keeping the internal pullups enabled?

Thanks again,
Yusif Nurizade