September 1999
ML6421*
Triple Phase and Sinx/x Equalized,
Low-Pass Video Filter
GENERAL DESCRIPTION
The ML6421 monolithic BiCMOS 6th-order filter provides
fixed frequency low pass filtering for video applications.
This triple phase-equalized filter with Sinx/x correction is
designed for reconstruction filtering at the output of a
Video DAC.
Cut-off frequencies are either 5.5, 8.0, or 3.0MHz. Each
channel incorporates a 6th-order lowpass filter, a first
order all-pass filter, a gain boost circuit, and a 75Ω coax
cable driver. A control pin (Range) is provided to allow
the inputs to swing from 0 to 1V, or 0.5 to 1.5V, by
providing a 0.5V offset to the input.
The unity gain filters are powered from a single 5V supply,
and can drive 1V
P-P
over 75Ω (0.5V to 1.5V), or 2V
P-P
over 150Ω (0.5V to 2.5V) with the internal coax drivers.
FEATURES
s
s
s
s
s
s
5.5, 8.0, 9.3, or 3.0MHz bandwidth
1x or 2x gain
6th-order filter with phase and amplitude equalizer
>40dB stopband rejection
No external components or clocks
±10% frequency accuracy over maximum supply
and temperature variation
<2% differential gain <2° differential phase
<25ns group delay variation
Drives 1V
P-P
into 75Ω, or 2V
P-P
into 150Ω
5V ±10% operation
*Some Packages Are Obsolete
s
s
s
s
BLOCK DIAGRAM
V
CC
B
8
V
CC
C
6
V
CC
5
V
CC
A
11
V
IN
A 15
3kΩ
BUF
LOW PASS
FILTER A
ALL
PASS
FILTER
SINX/X
EQUALIZER
1X/2X
BUF
10 V
OUT
A
3.33kΩ
I
BIAS
1kΩ
V
IN
B 16
3kΩ
BUF
LOW PASS
FILTER B
ALL
PASS
FILTER
SINX/X
EQUALIZER
1X/2X
BUF
3.33kΩ
9
V
OUT
B
I
BIAS
1kΩ
V
IN
C 2
3kΩ
RANGE 14
1kΩ
BUF
LOW PASS
FILTER C
ALL
PASS
FILTER
SINX/X
EQUALIZER
1X/2X
BUF
7
3.33kΩ
V
OUT
C
I
BIAS
12
GND
13
GNDA
4
GNDC
1
GNDB
3
GND
FilterA
Filter B
Filter C
ML6221-1
5.5MHz
5.5MHz
5.5MHz
1x GAIN
ML6421-3
8.0MHz
8.0MHz
8.0MHz
ML6421-4
8.0MHz
3.0MHz
3.0MHz
2x GAIN
ML6421-5 ML6421-7
5.5MHz
9.3MHz
5.5MHz
9.3MHz
5.5MHz
9.3MHz
Triple Input/Anti-aliasing Video Filter
1
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
