ML6426CS-15 MICRO-LINEAR [Micro Linear Corporation], ML6426CS-15 Datasheet - Page 6

• Manufacturer Part Number: ML6426CS-15
• Description: High Bandwidth Triple Video Filters with Buffered Outputs for RGB or YUV
• Manufacturer: MICRO-LINEAR [Micro Linear Corporation]

ML6426
FUNCTIONAL DESCRIPTION
The ML6426 is a triple monolithic continuous time video
filter designed for reconstructing video signals from an
YUV/RGB video D/A source. The ML6426 is intended for
use in AC coupled input and output applications.
The filters approximate a 4th-order Butterworth
characteristic with an optimization toward low overshoot
and flat group delay. All outputs are capable of driving
2V
of load capacitance. All outputs are capable of driving a
75 load at 1V
All channels are clamped during sync to establish the
appropriate output voltage swing range (DC restore). Thus
the input coupling capacitors do not behave according to
the conventional RC time constant. In most applications,
the ML6426's input coupling capacitors are only 0.1µF.
6
R IN
G IN
B IN
SYNC IN
P-P
0.1µF
0.1µF
0.1µF
into AC coupled 150 video loads, with up to 35pF
16
2
5
6
7
8
9
1
R IN A/Y IN A
R IN B/Y IN B
G IN A/U IN A
G IN B/U IN B
B IN A/V IN A
B IN B/V IN B
A/B MUX
SYNCIN
P-P
.
MUX
MUX
MUX
ACTIVE HIGH
TRANSCONDUCTANCE
TRANSCONDUCTANCE
TRANSCONDUCTANCE
ERROR AMP
ERROR AMP
ERROR AMP
Figure 1. Typical Application Schematic
DISABLE
November, 1999
15
Figure 2. SYNC IN Pulse Width
PW MIN = 2µS
+
+
+
–
–
–
V CCO
12
5V
0.5V
0.5V
0.5V
An external CMOS compatible H
which is Active High on the SYNC IN Pin. See Figure 2.
During sync, the feedback clamp sources/sinks current to
restore the DC level. The net result is that the average
input current is zero. Any change in the input coupling
capacitors' value will linearly affect the clamp response
times.
Each channel is essentially tilt-free. Each input is
clamped by a feedback amp which responds to the output
during sync.
The ML6426 is robust and stable under all stated load and
input conditions. Bypassing both V
ground ensures this performance.
V IH = 2.5V
V IL = 1.0V
V CC
5V
4
4th-ORDER
4th-ORDER
4th-ORDER
FILTER A
FILTER B
FILTER C
50% x V SYNC IN
GNDO
14
GND
2
2
2
3
G OUT /U OUT
B OUT /V OUT
R OUT /Y OUT
SYNC
CC
13
11
10
pins directly to
pulse is required
220µF 75
220µF 75
220µF 75
G
B
R