ML6424/ML6425
FUNCTIONAL DESCRIPTION
The ML6424 and ML6425 are monolithic CCIR601
continuous time video filters, designed for broadcast and
professional luminance and chrominance antialias and
reconstruction applications. They are fabricated using
Micro Linear’s 1.5µ, 4 GHz BiCMOS process. The filter
incorporates an input amplifier, programmable gain of 1x
or 2x set by the GAIN pin, a fifth order lowpass filter, a
third order allpass filter, and an output amplifier capable
of driving 75Ω to ground. The ML6425 provides sinx/x
equalization.
The ML6424–1 is intended for application as luminance
antialias processing, the ML6424–2 for chrominance
antialias, the ML6425–1 for luma reconstruction, and the
ML6425–2 for chroma reconstruction.
Input signals can be applied either through an AC coupling
capacitor (MODE = High/Low) or directly to the input pin
(MODE = float). With MODE = High, Y-Channel signal
can be applied to the input and the PULSE I/O pin
generates a clamping pulse for the U/V channel. When
MODE = Low, U/V channel signal can be applied to the
input. In this case, the PULSE I/O pin can take the pulse
signal generated from the PULSE I/O pin of the other chip
in the Y-channel. In the case of direct coupling, RANGE
should be adjusted according to the input signal range.
When RANGE is low, the input signal range is 0.5V to
1.5V. When the input signal goes down to 0V, RANGE
should be tied high. In this case, an offset is added to the
input so that the filter can process the 0V DC level.
The output amplifier is designed to drive up to 20mA peak
into a 75Ω load, or 17mA peak into a 150Ω load. Load
resistance less than 75Ω and/or output voltage above 1.5V
into 75Ω (2.5V into 150Ω) may cause signal distortion.
Good high frequency decoupling is required between
each power supply pin and ground, otherwise oscillations
and/or excessive crosstalk may occur.
1µF
Y
75Ω
6
ML6424-1
V
IN
P
V
IN
M
Y
75Ω
1µF
6
ML6424-1
V
IN
P
V
IN
M
7
7
+5V
12
MODE
+5V
12
MODE
4
PULSE I/O
4
PULSE I/O
1µF
U
75Ω
6
ML6424-2
V
IN
P
V
IN
M
U
75Ω
1µF
6
ML6424-2
V
IN
P
V
IN
M
7
7
12
MODE
12
MODE
4
PULSE I/O
4
PULSE I/O
1µF
V
75Ω
6
ML6424-2
V
IN
P
V
IN
M
V
75Ω
1µF
6
ML6424-2
V
IN
P
V
IN
M
7
7
12
MODE
12
MODE
4
PULSE I/O
4
PULSE I/O
Figure 1. YUV Filter with Sync on Y Input
and Auto Clamp On
Figure 2. YUV Filter with External Sync for U/V
5
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
