200 MHz I2C Compatible RGB Video Amplifier System
with OSD and DACs
The LM1262 pre-amp is an integrated CMOS CRT pre-amp.
The IC is I2C compatible, and allows control of all the pa-
rameters necessary to directly setup and adjust the gain and
contrast in the CRT display. Brightness and bias can be
controlled through the DAC outputs, and is well matched to
the LM2479 and LM2480 integrated bias clamp IC.
The LM1262 pre-amp is designed to work in cooperation
with the LM246X high gain driver family.
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.
The IC is packaged in an industry standard 24-lead DIP
molded plastic package.
n I2C compatible interface
n 4 external 8-bit DACs for bus controlled Bias and
n Vertical blank from sandcastle or input at pin 13 OR’ed
with horz. blank signal, option selected by I2C
n Contrast and brightness updates synchronous with
vertical blank, enabled by I2C
n Video set to black level through I2C
n Suitable for use with discrete or integrated clamp, with
software configurable Brightness mixer
n Power Save (Green) Mode, 80% power reduction
n Matched to 11-lead LM246X driver
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
Block and Connection Diagram
FIGURE 1. Order Number LM1262NA
See NS Package Number N24D
© 2002 National Semiconductor Corporation DS200404