鈥?/div>
7.1MHz Y and C 鏗乴ters, with CV out
14dB notch at 4.5MHz for sound trap
42dB stopband attenuation at 27MHz on Y, C, and CV
Better than 1dB 鏗俛tness 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 鏗俛tness on Y, C, and CV output
AC coupled inputs and outputs
0.4% differential gain on Y, C and CV channels, 0.4潞
differential phase on Y, C and CV channels
0.8% total harmonic distortion on all channels
DC restore with low tilt
General Description
The ML6415 is a dual Y/C 4th-order Butterworth lowpass
video 鏗乴ter optimized for minimum overshoot and 鏗俛t group
delay. The device also contains a summing circuit to gener-
ate 鏗乴tered 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 鏗乴ter distortion.
In a typical application, the Y and C input signals from
DACs are AC coupled into the 鏗乴ter. 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 2V
pp
into a 150
鈩?/div>
load (1V
pp
75
鈩?/div>
coax
load). The Y, C, CV, and notch channels have a gain of
approximately 2 (6dB) with 1V
pp
input levels.
Applications
鈥?Cable Set-top Boxes
鈥?Satellite Set-top Boxes
鈥?DVD Players
Block Diagram
VCC
7
SYNC STRIP,
REFERENCE,
AND TIMING
4TH 鈥?ORDER
FILTER
YIN
1
脳2
8
YOUT
gM
1V
+
危
+
gM
1V
脳2
6
CVOUT
NOTCH,
GROUP
DELAY
脳2
2
RF MOD
CIN
4
4TH 鈥?ORDER
FILTER
5
COUT
3
GND
REV. 2F May 2003
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