Newhaven Display Forum

Newhaven Products => OLEDs => Topic started by: mbrinks on April 21, 2014, 04:47:22 AM

Title: NHD-2.8-25664UCY2 PCB revisions?
Post by: mbrinks on April 21, 2014, 04:47:22 AM
Some time ago I bought a NHD-2.8-25664UCY2 at Digikey. The PCB is labeled "VER1.1".

The PCB has many problems with supply pins on the OLED module not having correct connections.
Problems I have found:
VLSS (pin 5 & 28) not connected to VSS.
VDDIO (pin 24) not connected to supply.
VDD (pin 25) is not connected to a decoupling capacitor.

Has a new revision been made, correcting these problems?

Best regards,
Michael
Title: Re: NHD-2.8-25664UCY2 PCB revisions?
Post by: Michael_L on April 21, 2014, 03:52:24 PM
Can I ask how you derived this information?  There has not been a revision made as there are currently no problems with the current VER1.1.
All signals are connected appropriately, making a complete and fully functional OLED module.
Title: Re: NHD-2.8-25664UCY2 PCB revisions?
Post by: mbrinks on April 22, 2014, 02:03:52 AM
I derived the information by simply following the PCB traces and by measuring resistance between components.

I would have to disagree on the module "making a complete and fully functional OLED module".
The module can under certain conditions be made to work in a more or less stable way. I suspect the reason it can function at all, is because the SSD1322 internally connects VSS and VLSS and the VDDIO supply will get some power through internal protection diodes from I/O pins. This is however not a solid design and violates requirements in the SSD1322 datasheet.

Title: Re: NHD-2.8-25664UCY2 PCB revisions?
Post by: Michael_L on April 22, 2014, 10:28:37 AM
Thank you for your feedback.  Are you currently using the display?  Are you experiencing any issues?  The display can be configured different ways, and the way we have designed it not only works for our testing purposes, but also for many of our customers.  If you would like to share any suggestions or design alternatives with us, please feel free to email us at nhtech@newhavendisplay.com.

Title: Re: NHD-2.8-25664UCY2 PCB revisions?
Post by: dotmatrix on August 26, 2014, 06:16:20 PM
i have been using this display fine, did you try a 2nd module??
Title: Re: NHD-2.8-25664UCY2 PCB revisions?
Post by: mbrinks on August 27, 2014, 04:32:25 AM
No, I didn't try a 2nd module. The problem is not the particular module I have, but the product design.
This is why I inquired about a new version of the product.
As far as I know Newhaven has not fixed the problem.