ML6416 Datasheet, PDF (1/7 Pages) Fairchild Semiconductor – S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation

www.fairchildsemi.com
ML6416
S-Video Filter with Summed Composite Output,
Sound Trap, and Group Delay Compensation
Features
• 7.1MHz Y and C filters, with CV out
• 14dB notch at 4.5MHz for sound trap
• 42dB stopband attenuation at 27MHz on Y, C, and CV
• Better than 1dB flatness to 4.5 MHz on Y, C, and CV
• RF Modulator output differential group delay between
400kHz and 3.58MHz is typically -170ns.
• No external frequency select components or clocks
• 9ns group delay flatness on Y, C, and CV output
• AC coupled inputs and outputs
• 0.4% differential gain on Y, C and CV channels, 0.4º
differential phase on Y, C and CV channels
• 0.8% total harmonic distortion on all channels
• DC restore with low tilt
Applications
• Cable Set-top Boxes
• Satellite Set-top Boxes
• DVD Players
General Description
The ML6416 is a dual Y/C 4th-order Butterworth lowpass
video filter optimized for minimum overshoot and flat group
delay. The device also contains a summing circuit to gener-
ate filtered composite video, an audio trap and group delay
compensation circuit to notch-out audio, providing an area
for the addition of the FM audio carrier(s) and mimic the
group delay distortion introduced at the transmitter. The
group delay predistortion compensates for the nominal TV
receiver IF filter distortion.
In a typical application, the Y and C input signals from
DACs are AC coupled into the filter. Both channels have DC
restore circuitry to clamp the DC input levels during video
sync. The Y and C channels use a separate feedback clamp.
The clamp pulse is derived from the Y channel.
The outputs are AC coupled. The Y, C, CV, and modulator
outputs can drive 2VP-P into a 150Ω load (1VP-P 75Ω coax
load). The Y, C, CV, and notch channels have a gain of
approximately 2 (6dB) with 1VP-P input levels.
Block Diagram
YIN 1
SYNC STRIP,
REFERENCE,
AND TIMING
4TH – ORDER
FILTER
VCC
7
×2
8 YOUT
CIN 4
gM
1V
gM
1V
+
Σ
×2
+
4TH – ORDER
FILTER
×2
3
GND
NOTCH,
GROUP
DELAY
6 CVOUT
2 RF MOD
5 COUT
REV. 1.0.6 8/26/02