Fairchild Semiconductor ML6428 Datasheet
ML6428
www.fairchildsemi.com
S-Video Filter and 75
Ω Line Drivers with Summed
Composite Output
Features
• 6.7MHz Y and C filters, with CV out for NTSC or PAL
•75Ω cable line driver for Y, C, CV, and TV modulator
• 43dB stopband attenuation at 27MHz
• 1dB flatness up to 4.8MHz
• No external frequency select components or clocks
• 12ns group delay flatness up to 10MHz
• 5% overshoot on any input edge
•AC coupled input and output (ML6428CS-1)
•AC coupled input and DC coupled output
(ML6428CS-2)
• 0.4% differential gain on all channels, 0.4º differential
phase on all channels
• 0.7% total harmonic distortion on all channels
• 5V ±10% operation
• DC restore with low tilt
General Description
The ML6428 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 generate filtered composite video.
The Y and C input signals from DACs are AC coupled into
the ML6428. Both channels have DC restore circuitry to
clamp the DC input levels during video sync. The Y channel
uses a sync tip clamp. The CV and the C channels share a
feedback clamp.
All outputs must be AC coupled into their loads for the -1
version. The -2 version must be DC coupled. All inputs (-1
and -2 versions) are AC coupled. The Y or C outputs can
drive 2VP-P into a 150Ω load, while the CV output can drive
2VP-P into 75Ω. Thus the CV output is capable of driving
two independent 150Ω loads to 2VP-P.
On the CV output, one of the 75Ω loads can be shorted to
ground with no loss of drive to the remaining load. The Y, C
and CV channels have a gain of 2 (6dB) with 1VP-P input
levels.
Block Diagram
YIN
CIN
VCCOVCC
72
1
SYNC TIP CLAMP
4
4th-ORDER
FILTER
TRANSCONDUCTANCE
ERROR AMP
4th-ORDER
FILTER
3
GND
8
6
5
YOUT
CVOUT
COUT
BUFFER
+
Σ
+
BUFFER
BUFFER
REV. 1B April 2003
ML6428 DATA SHEET
Pin Configuration
ML6428
8-Pin SOIC (S08)
YIN
VCC
GND
CIN
1
2
3
4
TOP VIEW
8
YOUT
7
VCCO
6
CVOUT
5
COUT
Pin Description
Pin Name Function
1 YIN Luminance input
2 VCC 5V supply for filters and references
3 GND Ground
4 CIN Chrominance input
5 COUT Chrominance output
6CVOUT Composite video output
7 VCCO 5V supply for output stages
8YOUT Luminance output
Electrical Characteristics
Absolute Maximum Ratings
Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum
ratings are stress ratings only and functional device operation is not implied.
Parameter Min. Max. Units
DC Supply Voltage -0.3 7 V
Analog & Digital I/O GND – 0.3 V
Output Current (Continuous)
CV Channel
C and Y Channels
Junction Temperature 150 °C
Storage Temperature Range –65 150 °C
Lead Temperature (Soldering, 10 sec) 260 °C
Thermal Resistance (θJA)67°C/W
Operating Conditions
Parameter Min. Max. Units
Temperature Range 0 70 °C
VCC Range 4.5 5.5 V
+ 0.3 V
CC
60
30
mA
mA
2 REV. 1B April 2003
DATA SHEET ML6428
Electrical Table Unless otherwise specified, V
outputs must be AC coupled, ML6428-2 outputs must be DC coupled. TA = Operating Temperature Range
Symbol Parameter Conditions Min. Typ. Max. Units
ICC Supply Current No Load (VCC = 5.0V) 52 80 mA
AV Low Frequency Gain (All Channels) VIN = 100mVP-P at 300KHz 5.34 6.0 6.65 dB
C DC Output Level (During Sync) Sync Present on Y 1.7 1.9 2.3 V
Y Sync Output Level ML6428-1 Sync Present on Y 0.7 0.9 1.3 V
ML6428-2 Sync Present on Y 0.35 0.54 0.95 V
Y+C Sync Output
Level
tCLAMP Clamp Response Time (Y Channel) Settled to Within 10mV 2 ms
f1dB -1dB Bandwidth (Flatness)
(All Channels)
fC -3dB Bandwidth (Flatness)
(All Channels)
0.8fC 0.8 x fC Attenuation (Y, C) 1.5 dB
fSB Stopband Rejection (All Channels) fIN = 27MHz to 100MHz worst
Vi Input Signal Dynamic Range AC Coupled ML6428-1, -2 1.0 1.4 VP-P
NOISE Output Noise (All Channels) 25Hz to 50MHz 2.3 mVRMS
OS Peak Overshoot (All Channels) 2VP-P Output Pulse (loaded) 4.3 %
ISC Output Short Circuit Current
(All Channels)
CL Output Shunt Capacitance
(All Channels)
dG Differential Gain (All Channels) All Outputs 0.4 %
dΦ Differential Phase (All Channels) All Outputs 0.4 °
THD Output Distortion (All Channels) VOUT = 1.8VP-P,
XTALK Crosstalk From C Input of 0.5VP-P at
PSRR PSRR (All Channels) 0.5VP-P (100kHz) at VCC –49 dB
tpd Group Delay (All Channels) 100kHz 60 ns
∆tpd Group Delay Deviation from
Flatness
(All Channels)
tSKEW Skew Between Y & C Outputs 1 ns
ML6428-1 Sync Present on Y 0.7 0.92 1.3 V
ML6428-2 Sync Present on Y 0.35 0.48 0.95 V
= 5V ±10%, All inputs AC coupled with 100nF, ML6428-1
CC
4.0 4.8 MHz
6.7 MHz
–42 –38 dB
case
VOUT C, Y, or CV (Note 2) 100 mA
All Outputs 35 pF
0.7 %
Y/C Out at 3.58MHz/4.43MHz
–55 dB
3.58MHz/4.43MHz, to Y
Output
From Y Input of 0.4VP-P at
3.58MHz, to C Output
to 3.58MHz (NTSC) 4 ns
to 4.43MHz (PAL) without
peaking (see Figures 7 to 11)
to 10MHz 12 ns
–58 dB
7ns
1
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions.
2: Sustained short circuit protection limited to 10 seconds.
REV. 1B April 2003 3
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