I am designing a DVI to LVDS adapter. It needs to support the following panels:
WXUGA: 1920 x 1200, 60Hz, 24-bit color
1080p: 1920 x 1080, 60Hz, 24-bit color
From previous postings it looks like the appropriate devices to use are:
- DVI Receiver: TFP401A or TFP403
- LVDS Transmitter: DS90C387A
Can you please confirm that these are the prefered devices, and some insight to the selection of the the TSP401A vs. TFP403.
Can I expect that there should not be an issue with display instability, assuming:
- All the app notes are followed
- Appropriate controlled impedence traces
- Correct EEID data
- Stable power supply
?
Regarding the configuration of these devices, in one post from Peter Kuo, I saw:
3) TFP401A can output two 24bit RGB pixels from 48 output pins (dual pixel output) OR one 24bit RGB pixel from 24 output pins (single pixel output). My DVI-LVDS board allowed me to configure DS90C387A to accept either "dual pixel" or " single pixel" from TFP401A. However, I had some display issues on the LG 23" 1920x1080 LCD monitor when TFP401A was in "dual pixel output " mode, and DS90C387A in " dual pixel in-dual pixel out" mode. The moment I configured TFP401A in " single pixel output" mode, and DS90C387A to " single-to-dual mode", the LG 23" worked just fine.
This seems counter-intuitive:
- Recommended timing for WXUGA display gives a 154MHz pixel rate
- TFP401A 2 pix/clk, DS90C387A Dual Mode => TXCLK_In = 77 MHz, maximum allowed = 112 MHz, margin = 45%
- TFP401A 1 pix/clk, DS90C387A Single in, Dual out mode => TXCLK_In = 154 MHz, maximimum allowed = 170 MHz, margin = 9%
There is much greater margin to the maximum allowed TXCLK_In in the 2 pix/clk mode, so one might think this would give the better (more stable) display output. Am I missing something that would favor the 1 pix/clk configuration?
Thank you in advance,
Ian
