Product category:
Analogue and Mixed Signal ICs
News Release from: Zetex | Subject: ZXFV4583 and ZXFV4089
Edited by the Electronicstalk Editorial
Team on 23 January 2003
Two-chip solution to solve composite
video
The ZXFV4583 sync separator and ZXFV4089 DC restoration amplifier provide a two-chip solution for the management of composite video signals.
The ZXFV4583 sync separator and ZXFV4089 DC restoration amplifier provide a two-chip solution for the management of composite video signals Used together in applications including CCTV, video capture, mixing and special effects, the chipset is pin compatible with standard industry alternatives
This article was originally published on Electronicstalk on 6 Feb 2002 at 8.00am (UK)
Related stories
MOSFETs to give that home theatre sound
Zetex has launched a series of four N- and P-channel MOSFETs providing all the performance demanded by Class D audio systems.
Chip takes control of brushless fans and blowers
The ZXBM2000 series of controller ICs offers a complete variable speed control solution for two-phase, DC brushless fan and blower motors up to 100W.
Acting as a black level clamp, the ZXFV4089 provides brightness level stability in video systems characterised by wide bandwidth, low distortion and low power consumption.
AC coupled, the composite video signal is subject to DC drift due to the variable content of the intensity information.
This needs to be corrected prior to digital conversion.
Containing a sample and hold circuit and a low distortion video amplifier, the ZXFV4089 therefore assures DC restoration of the video signal.
From the back porch pulse, the device establishes the black level reference for the following part of the signal containing the intensity information.
The output is a video signal permanently clamped to a reference voltage, normally 0V.
Configured using three external resistors, the ZXFV4583 separates out vertical, horizontal and composite synchronisation signals from Pal, NTSC, Secam and other standard and nonstandard composite video signals.
Accurate timing of sync extraction is achieved by the device through a sample and hold process that determines the 50% point on the negative edge of the sync pulse.
An optional on-chip lowpass filter can also be employed to alleviate the effects of the colour carrier, while interlaced video formats are accommodated by an odd/even logic output.
Loss of signal detection, at a level set by one of the external resistors, initiates a logic high output.
• Zetex: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
