资 源 简 介
The EL4581 extracts TIminginformaTIon from standard negaTIvegoing video sync found in NTSC, PALand SECAM broadcast systems. It can also be used in nonstandard formats and with computer graphics systems athigher scan rates, by adjusTIng a single external resistor.When the input does not have correct serration pulses in thevertical interval, a default vertical output is produced.Outputs are composite sync, vertical sync, burst/back porchoutput, and odd/even output. The later operates only ininterlaced scan formats.The EL4581 provides a reliable method of determiningcorrect sync slide level by setting it to the mid-point betweensync tip and blanking level at the back porch. This 50% levelis determined by two internal self timing sample and holdcircuits that track sync tip and back porch levels. This alsoprovides a degree of hum and noise rejection to the inputsignal, and compensates for varying input levels of 0.5VP-Pto 2.0VP-P.A built in linear phase, third order, low pass filter attenuatesthe chroma signal in color systems to prevent incorrectly setcolor burst from disturbing the 50% sync slide.This device may be used to replace the industry standardLM1881, offering improved performance and reduced powerconsumption.The EL4581 video sync separator is manufactured usingElantec’s high performance analog CMOS process.
