LM1296 Raster Geometry Correction System for Multi-Frequency Displays General Description The LM1296 is a monolithic IC for use in the raster scanning circuitry of a multi-frequency CRT monitor. The IC provides an S-corrected sawtooth waveform and a variable DC output voltage. These two outputs drive the vertical deflection amplifier. It also provides another waveform for East-West geometry correction which includes pincushion, corner, and trapezoid controls. The geometry correction is controlled by DC input voltages from 0V to 4V. The raster height and the raster vertical position can be controlled by two DC voltage input pins that adjust the sawtooth waveform amplitude and the variable DC output voltage. The East-West correction of the LM1296 has height tracking and vertical position tracking capabilities. As the height or position of the raster is adjusted the geometry correction is maintained by the chip automatically. The LM1296 is packaged in a 16-pin plastic DIP package. Features n Vertical scanning frequency 50 Hz–165 Hz n Accepts either polarity of V sync n DC-controlled correction terms n Raster vertical position control n Vertical S-correction (linearity) control n East-West pincushion control n East-West trapezoid control n East-West corner control n Provides both polarities of correction output n East-West correction tracks raster vertical position and height n Compatible with LM1290 and LM1292 horizontal PLL Applications n Vertical deflection of monitors