Samsung LT133X1-106 LCD panel
The Samsung LT133X1-106 is a fairly small (13.3 inch), XGA (1024x768), full-colour (6-bit RGB) TFT-LCD panel with a CCFL backlight and an LVDS interface. They were used in a number of laptop computers, most notably the Dell Latitude CP and CPi series -- this means they're quite commonly found on the surplus market (usually as "used-but-good" spares from laptop spares dealers), and as a result they're cheap.
I'm working on connecting one of these panels to an Enterpoint Drigmorn2 development board -- this page will document my progress.
Inverter -- Dell DAINVMPB201 Rev 3B
This is one of the really neat aspects of the LT133X1. The inverter is a single module which can usually be found wrapped in a tin shield and either glued or bolted onto the back of the LCD panel. It has some really nice features:
- Standard power supply voltages (5V and 12V)
- Built from standard parts for which data is available (TI/Unitrode UC3872 Resonant Lamp Ballast Driver, Dallas DS1803 Digital Potentiometer).
- Lamp brightness controlled over an I2C/SMBus serial link ("W1" output)
- Second 'variable voltage' output ("W0", output range is unknown but expected to be from 0V to 5V and has 8-bit resolution)
The pinout isn't documented anywhere that I can see, so I reverse engineered it by tracing pins with a multimeter. I started by figuring out where the ground pins were (they're usually the easiest to find), then working backwards to find Vcc, SDA, SCL and so on. Finally, a bit of track-following revealed the function of the last pin (the W0 output from the Dallas digi-pot).
The pinout is as follows:
||UC3872 Vc (+12V)
||UC3872 Vc (+12V)
||UC3872 Enable (5V = lamp on, 0V = lamp off)
||DS1803 Vcc (5V, keep active)
||I2C Serial Data (SDA)
||I2C Serial Clock (SCL)
||DS1803 pin 12 (Wiper 0)
||UC3872 Vcc (5V, can be switched off to save power)
When holding the board so the Dell logo is at the bottom right, pin 10 is at the top of the board, and pin 1 is at the bottom.