LM1267 RGB Video Amplifier IC

The LM1267 RGB Video Amplifier IC designed as an integrated CMOS CRT pre-amp. The LM1267 is  compatible with I2C. And it allows control of all the parameters required to directly setup and adjust the gain and contrast in the CRT display. The Brightness and bias of the pre-amp controlled via the DAC outputs, and is well matched to the LM2479 and LM2480 integrated bias clamp IC. The LM1267 pre-amp designed explicitly to work in cooperation with the LM246X high gain driver family. Meanwhile, the Black level clamping of the signal carried out directly on the AC coupled input signal into the high impedance preamplifier input. As a result, eliminates the need for additional black level clamp capacitors. The IC is manufactured in an industry standard 24-lead DIP molded plastic package.

All functions of the LM1267 controlled via through the I2 C Bus. For the normal operation of the LM1267,  a very accurate reference voltage is not necessary. This reference voltage required generated in the VRef block. In order, to ensure an accurate voltage over temperature, an external resistor used to set the current in the VRef stage. Hence, the output of the VRef stage is fed to a number of blocks in the video section and also to pin 21. As a result, this pin 21 allows capacitor  filtering on the VRef output and offers an accurate external  reference. Highly recommended to use a  buffer with this reference. The LM1267 comes in a full ESD protection with special consideration  to maximizing arc-over robustness.  The human body model ESD susceptibility of the LM1267 designed as 3.5 kV.

APPLICATION:

• Low end pin  15’ and pin 17’ bus controlled monitors with OSD
• 1024 X 768 displays up to 85 Hz requiring OSD capability
• Very low cost device with LM246X driver