Preventing display damage due to over-volting

[netdudeuk]

Hi

I have bought a couple of these displays (https://www.aliexpress.com/item/32949282762.html?spm=a2g0s.9042311.0.0.14ed4c4dKHemnJ) as used here in a project -

https://twitter.com/chrishutchinson/status/1136743837244768257

One of the reviews on AliExpress states 'But be careful-on the module the power io is supplied from 1.8 v regulator, which means the input of the data bus can not be higher (i approve on the basis of my sad experience-the previous same display i burned, by connecting directly to esp32 conclusions)' but the guy doing the project seems to have connected his display straight to the Pi.

There's the same project here but with a slightly different display that is also connected directly -

https://www.balena.io/blog/build-a-raspberry-pi-powered-train-station-oled-sign-for-your-desk/

Display controller info here -

https://www.newhavendisplay.com/app_notes/SSD1322.pdf

Do I need to use level shifters or was the review comment wrong ?

Thanks

[tooki]

I think the commenter is wrong. The datasheet says that the data lines can't be higher than the low-power (logic) power input. But the datasheet also says that said low power input needs 2.4-3.5V. It's highly unlikely that the display module is putting 1.8V onto the power input, well below spec.

[netdudeuk]

I think the commenter is wrong. The datasheet says that the data lines can't be higher than the low-power (logic) power input. But the datasheet also says that said low power input needs 2.4-3.5V. It's highly unlikely that the display module is putting 1.8V onto the power input, well below spec.

Thanks for the reply.  Please would you be able to elaborate ?

[tooki]

Just to recap, the datasheet says that the maximum voltage on an input is the same as the low-power supply voltage. E.g if you’re running it on 3.3V, then you can apply up to 3.3V on an input, but if you’re running it on 3.0V, then you can’t apply more than 3.0V on an input.

The commenter said the module uses a supply voltage of 1.8V. But the datasheet says the IC needs 2.4V minimum to operate. So either the commenter is wrong, or the commenter had a faulty module, or the commenter was using too low an input voltage to the module (such that the regulator can’t regulate properly, or the module (for some inexplicable reason) is under powering the chip on purpose.

My guess would be that the commenter is wrong.