LM1236 Datasheet | National Semiconductor

Description The LM1236 pre-amp is an integrated CMOS CRT preamp. It has an I2C patible interface which allows control of all the parameters necessary to directly setup and adjust the gain and contrast in the CRT display. Brightness and bias can be controlled through the DAC outputs, which are well matched to the LM2479 and LM2480 integrated bias clamp ICs. The LM1236 preamp is also designed to be patible with the LM246x high gain driver family. Black level clamping of the video signal is carried out directly on the AC coupled input signal into the high impedance preamplifier input, thus eliminating the need for additional clamp capacitors. Horizontal and vertical blanking of the outputs is provided. Vertical blanking is optional and its duration is register programmable. The IC is packaged in an industry standard 24-lead DIP molded plastic package. n OSD Window Fade In/Fade Out n OSD Half Tone Transparency n OSD override allows OSD messages to override video and the use of burn-in screens with no video output. n 4 DAC outputs (8-bit resolution) for bus controlled CRT bias and brightness n Spot killer which blanks the video outputs when VCC falls below the specified threshold n Suitable for use with discrete or integrated clamp, with software configurable brightness mixer n 4-Bit Programmable start position for internal Horizontal Blanking n Horizontal blanking and OSD synchronization directly from deflection signals. The blanking can be disabled, if desired. n Vertical blanking and OSD synchronization directly from deflection signals. The blanking width is register programmable and can be disabled, if desired. n Power Saving Mode with 65% power reduction n Matched to LM246x driver and LM2479/80 bias IC’s Features n Internal 254 character OSD ROM usable as either (a) 190 2-color plus 64 4-color characters, (b) 318 2-color characters, or (c) some bination in between n Internal 512 character RAM, which can be displayed as one single or two independent windows n...