March 2002
LM1262
200 MHz I2C Compatible RGB Video Amplifier System
with OSD and DACs
n 4 external 8-bit DACs for bus controlled Bias and
Brightness
General Description
The LM1262 pre-amp is an integrated CMOS CRT pre-amp.
n Vertical blank from sandcastle or input at pin 13 OR’ed
The IC is I2C compatible, and allows control of all the pa-
with horz. blank signal, option selected by I2C
rameters necessary to directly setup and adjust the gain and
n Contrast and brightness updates synchronous with
contrast in the CRT display. Brightness and bias can be
vertical blank, enabled by I2C
controlled through the DAC outputs, and is well matched to
the LM2479 and LM2480 integrated bias clamp IC.
n Video set to black level through I2C
n Suitable for use with discrete or integrated clamp, with
The LM1262 pre-amp is designed to work in cooperation
software configurable Brightness mixer
with the LM246X high gain driver family.
n Power Save (Green) Mode, 80% power reduction
n Matched to 11-lead LM246X driver
Black level clamping of the signal is carried out directly on
the AC coupled input signal into the high impedance pream-
plifier input, thus eliminating the need for additional black
level clamp capacitors.
Applications
n High end 19” and 21” bus controlled monitors with OSD
n 1600 X 1200, 85 Hz or higher applications
n Low cost and high performance system with LM246X
driver
The IC is packaged in an industry standard 24-lead DIP
molded plastic package.
Features
n I2C compatible interface
Block and Connection Diagram
DS200404-1
FIGURE 1. Order Number LM1262NA
See NS Package Number N24D
© 2002 National Semiconductor Corporation
DS200404
www.national.com