LM2457

www.DataSheet4U.com October 2000 LM2457 Monolithic Triple 7.5nS CRT Driver With Integrated Clamp and G1 Blanking LM2457 Monolithic Triple 7.5nS CRT Driver With Integrated Clamp and G1 Blanking General Description The LM2457 driver is an integrated high voltage triple CRT driver circuit designed for use in color monitor applications. The input signal interface to the IC is a multiplexed signal containing both clamp and video signal information, relative to an external 1.7 VDC reference. The IC contains three high gain, differential input, high input impedance, wide band amplifiers which directly drive the RGB cathodes of a CRT. Each channel has its gain internally set to -52 and can drive CRT capacitive loads as well as resistive loads present in other applications, limited only by the package’s power dissipation. Integrated with the driver is a triple video clamp circuit for DC recovery of each of the AC coupled video outputs. The DC clamp circuit amplifies the clamp signal that is multiplexed on the video signal input. The DC clamp amplifiers are high gain, differential input, high input impedance amplifiers, setting a low impedance DC level at the clamp output which can be used to restore the DC level of the cathode drive. Each channel has a gain that is internally set to +75. Also integrated within the package is a 43Vp-p vertical blanking driver that is designed to drive the vertical retrace blanking signal to the G1. This is a current limited, low impedance output capa...