EDP to LVDS - Page 1
Forum section: electronics / beginners

author: Xelef2000
author_rank: Newbie
timestamp: April 20, 2023, 09:54:29 am
content: I am currently trying to replace the motherboard of an early 2011 MacBook Pro (a1286) with the motherboard of a framework laptop (https://frame.work/marketplace/mainboards), to save it from the landfill.I am currently researching the feasibility of this project. I’m quite sure that it will fit space-wise (the MacBook is a bit wider and almost 1 cm deeper).Thanks to the eevblog I also know how to hook up the keyboard and trackpad (https://www.eevblog.com/forum/projects/making-a-standalone-usb-trackpad-from-macbook-pro-(mid-2012)-trackpad/msg4676602/#msg4676602).But I am currently struggling with the display since my knowledge of integrated display standards is lacking.The MacBook display uses a 2 channel LVDS interface (https://drive.google.com/file/d/1oK7pVRmHImKTNKWwxXv-sZcKGYWy38z2/view)The framework has two display output options, 4 lane eDP 1.4b, and Displayport over usb-c. I’d prefer to use the EDP output, to not take up more ports than needed, and to utilize features like display shutoff when the lid is closed and brightness adjustments from the OS.I was able to find the PTN3460 bridge chip but it only supports 2-lane eDP up to DP 1.2a. (https://datasheet.lcsc.com/lcsc/2106070806_NXP-Semicon-PTN3460IBS-F2MP_C2674387.pdf)My Questions are:Can I use the PTN3460 and just drop 2 lanes and is it backward compatible (bandwidth shouldn't be an issue since the MacBook display has a lower resolution)?Alternatively, can I use a standard DP to HDMI converter like the MCDP2900 with EDP, and what would be the best HDMI to LVDS chip afterward?

author: barshatriplee
author_rank: Regular Contributor
timestamp: April 20, 2023, 10:15:00 am
content: I think it's better to use an eDP to LVDS converter like the CH7511B.https://www.silicondevice.com/file.upload/images/Gid655Pdf_CH7511B%20Brief%20Datasheet%20V1.13.pdf

author: Xelef2000
author_rank: Newbie
timestamp: April 20, 2023, 11:13:34 am
content: Thanks, I haven't found this chip yet.But it has the same limitations as the PTN3460, only to eDP lanes at 1.2.I'm not sure if I can just not connect 2 of the 4 lanes from the mainboard and if eDP is backward compatible.

author: AshtrayWasp
author_rank: Newbie
timestamp: April 05, 2025, 10:19:42 pm
content: Hi, I'm currently considering doing the same thing with a 2015 A1398, were you able to connect the eDP to the LVDS display?

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: April 06, 2025, 03:32:51 pm
content: Correct me if I'm wrong, but even with the conversion of the [Framework motherboard] EDP to [Macbook Display] LVDS, isn't there the high-potential for problems to arise at the firmware level, due to the Framework laptop expecting a different resolution of display to be connected? I'd imagine once booted into Windows/whatever O.S, it'd be fine, but accessing the BIOS/UEFI may be problematic?

author: AshtrayWasp
author_rank: Newbie
timestamp: April 06, 2025, 04:16:31 pm
content: You make a good point, I hadn't thought of that.I don't really know enough to be able to know but I have foundthisas an alternative, although it would mean no sleep on screen close as it would just be an external screen.The Framework's resolution seems to be 2256x1504 native, and the A1398's display is 2880x1800 native, so I don't think there would be an issue when using BIOS, but this is a guess.Also this was all prompted by seeingthis postwhere he used an LG 17" 2560x1600 screen, which he doesn't mention having issues with.