Maxim MAX7443 Triple-channel video reconstruction filter and buffer for composite and y/c output Datasheet

19-2749; Rev 0; 1/03
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
Features
♦ Triple-Channel Filter and Buffer for CVBS and
Y/C (S-Video)
♦ Filter Response Ideal for NTSC, PAL, and
Interlaced SDTV Signals
♦ 41dB (typ) Stopband Attenuation at 27MHz
♦ -0.3dB (typ) Passband Response
♦ Low Blanking Level Voltage Allows DC-Coupled
Output
♦ Each Channel Drives Two 150Ω Video Loads
♦ +5V Single-Supply Voltage
♦ Tiny 8-Pin Thin QFN or 8-Pin SO Packages
Ordering Information
The MAX7443/MAX7444 are available in a tiny 8-pin thin
QFN and an 8-pin SO package with exposed pad, and
are fully specified over the -40°C to +85°C extended
temperature range.
PART
TEMP RANGE
PIN-PACKAGE
TOP
MARK
MAX7443ETA
-40°C to +85°C
8 Thin QFN-EP*
AFX
Applications
MAX7443ESA
-40°C to +85°C
8 SO-EP*
MAX7444ETA
-40°C to +85°C
8 Thin QFN-EP*
MAX7444ESA
-40°C to +85°C
8 SO-EP*
Set-Top Boxes/HDR/DVD
Digital VCRs
Security Cameras/Digital
Cameras
Every Composite,
S-Video Output for NTSC,
PAL, SDTV
Game Consoles
—
AFY
—
*EP = Exposed pad.
Selector Guide appears at end of data sheet.
Functional Diagram
VCC
*
*
ENCODER
YIN
D/A
6dB/
9.5dB/
12dB
LOWPASS
FILTER
YOUT
*
MAX7443
MAX7444
D/A
CIN
LOWPASS
FILTER
Σ
6dB/
9.5dB/
12dB
6dB/
9.5dB/
12dB
CVOUT
*
COUT
*
*
GND
GSET
*OPTIONAL
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX7443/MAX7444
General Description
The MAX7443/MAX7444 are low-cost, triple-channel
video reconstruction filters for S-video and CVBS video
signals. These devices are ideal for anti-aliasing and
DAC smoothing video applications such as set-top
boxes, DVD players, hard-disk recorders (HDRs), and
personal video recorders. These filters operate from a
single +5V supply. They are optimized for NTSC, PAL,
and standard-definition digital TV (SDTV) video systems.
Each channel consists of a lowpass filter and an
adjustable-gain output buffer capable of driving two
standard 150Ω video loads. The output buffers can drive
either an AC or a DC load such that the blanking level
voltage after the backmatch resistor is less than 1V. The
Y and C video inputs are summed to produce the composite video output. The MAX7444 offers highfrequency boost to improve picture sharpness. The
MAX7443 has a maximum flat-frequency response.
MAX7443/MAX7444
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................................+6V
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
Maximum Current into Any Pin Except VCC and GND .....±50mA
Continuous Power Dissipation (TA = +70°C)
8-Pin Thin QFN (derate 24.4mW/°C above +70°C) ...1951mW
8-Pin SO (derate 18.9mW/°C above +70°C)..............1509mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω to GND for DC-couple, RL = 75Ω to VCC/2 for AC-couple, CYIN = CCIN = 0.1µF,
TA = TMIN to TMAX, GSET = GND (6dB) and VCC (9.5dB), unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
f = 100kHz to 4.2MHz,
relative to 100kHz
Passband Response
Stopband Attenuation
CONDITIONS
ASB
MIN
TYP
MAX
UNITS
MAX7443
-0.8
-0.3
+0.1
MAX7444
-0.1
+0.6
+0.92
39
41
dB
0.6
dB
f = 27MHz
dB
Boost Amplitude
f = 4.2MHz, MAX7444
Differential Gain
dG
5-step modulated
staircase
Gain = 6dB,
9.5dB, 12dB
0.15
0.4
%
Differential Phase
dθ
5-step modulated
staircase
Gain = 6dB,
9.5dB, 12dB
0.15
0.4
Degrees
SNR
Peak signal (2VP-P) to
RMS noise, f = 100Hz to
50MHz
Gain = 6dB,
9.5dB, 12dB
∆tg
Deviation from 100kHz to
4.1MHz
Signal-to-Noise Ratio
Group Delay Deviation
67
73
dB
MAX7443
8
20
MAX7444
12
30
ns
Line-Time Distortion
HDIST
18µs, 100 IRE bar
0.3
%
Field-Time Distortion
VDIST
130 lines, 18µs, 100 IRE bar
0.5
%
To ±1%
100
Lines
Clamp Settling Time
Output DC Clamp Level
Low-Frequency Gain Accuracy
Group Delay Matching
Channel-to-Channel Crosstalk
Input Leakage Current
2
AV
tg(MATCH)
XTALK
YOUT
0.6
0.8
CVOUT
0.6
0.8
1.0
1.0
COUT
1.44
1.6
1.97
f = 100kHz, relative to 6dB
-3.5
+2
V
%
Low-frequency channel-to-channel matching,
f = 100kHz for YOUT and COUT
2
ns
f = 100kHz to 3.58MHz, gain = 6dB
61
dB
IIN
_______________________________________________________________________________________
10
µA
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
(VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω to GND for DC-couple, RL = 75Ω to VCC/2 for AC-couple, CYIN = CCIN = 0.1µF,
TA = TMIN to TMAX, GSET = GND (6dB) and VCC (9.5dB), unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Input Dynamic Swing
SYMBOL
CONDITIONS
MIN
TYP
MAX
YINP-P
GSET = GND (6dB)
1.2
CINP-P
GSET = GND (6dB)
0.9
UNITS
VP-P
SUPPLY
Supply Voltage Range
VCC
Supply Current
4.75
ICC
Power-Supply Rejection Ratio
PSRR
VCC = +5.25V, no load
88
VIN = 100mVP-P, f = 0 to 3.5MHz
33
5.25
V
110
mA
dB
Typical Operating Characteristics
(VCC = +5V, TA = +25°C, unless otherwise noted.)
AMPLITUDE vs. FREQUENCY
-40
0.5
0
MAX7443
-0.5
-1.0
-60
NORMALIZED TO 0dB
MAX7443/44 toc03
MAX7444
150
100
PHASE (DEGREES)
1.0
AMPLITUDE (dB)
-20
1.5
PHASE RESPONSE vs. FREQUENCY
200
MAX7443/44 toc02
MAX7443/44 toc01
0
AMPLITUDE (dB)
PASSBAND AMPLITUDE vs. FREQUENCY
2.0
50
0
-50
-100
-1.5
-150
NORMALIZED TO 0dB
-80
-2.0
10
-200
0.1
1
10
0.1
1
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
GROUP DELAY vs. FREQUENCY
2T RESPONSE (1 IRE = 7.14mV)
MODULATED 12.5T RESPONSE
(1 IRE = 7.14mV)
80
MAX7443/44 toc05
MAX7443/44 toc04
90
GROUP DELAY (ns)
100
YIN
200mV/div
70
10
MAX7443/44 toc06
1
YIN
200mV/div
60
50
YOUT
200mV/div
YOUT
400mV/div
40
0.1
1
10
200ns/div
400ns/div
FREQUENCY (MHz)
_______________________________________________________________________________________
3
MAX7443/MAX7444
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VCC = +5V, TA = +25°C, unless otherwise noted.)
80
75
70
65
-15
10
35
60
85
TEMPERATURE (°C)
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
MAX7443/44 toc08
DIFFERENTIAL PHASE (DEGREES) DIFFERENTIAL GAIN (%)
MAX7443/44 toc07
85
-40
1
2
3
NAME
1
YIN
2
GSET
5
6
1
2
3
FUNCTION
4
5
YIN
200mV/div
7
YOUT
200mV/div
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
6
7
10µs/div
These devices operate from a single +5V supply. The
filters have a nominal cutoff frequency optimized for
NTSC, PAL, and SDTV.
Filter
Luma (Y) Input
Gain-Setting Control Input. See Table 1
for values.
3
CIN
Chroma (C) Input
4
GND
Ground
5
VCC
5V Power Supply
6
COUT
7
CVOUT
8
YOUT
Chroma (C) Output
Composite Video Output
Luma (Y) Output
Detailed Description
The primary function of the MAX7443/MAX7444 is to filter and buffer the encoder DAC outputs that contain
digital video information in applications such as set-top
boxes, hard-disk recorders, DVD players, and digital
VCRs. These devices reconstruct and clean up analog
video signals. Each MAX7443/MAX7444 consists of a
lowpass filter and an adjustable-gain output video
buffer that is capable of driving two standard 150Ω
video loads. The luma (YIN) and chroma (CIN) video
inputs are summed internally to provide the composite
(CVOUT) video output.
4
4
DIFFERENTIAL PHASE
Pin Description
PIN
MULTIBURST RESPONSE
DIFFERENTIAL GAIN
90
MAX7443/44 toc09
SUPPLY CURRENT
vs. TEMPERATURE
SUPPLY CURRENT (mA)
MAX7443/MAX7444
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
Filter Response
The reconstruction filter consists of two 2nd-order
Sallen-Key stages. The Butterworth-type response features a maximally flat passband for NTSC and PAL
bandwidths. The stopband offers 41dB (typ) of attenuation at sampling frequencies of 27MHz and above (see
Typical Operating Characteristics).
High-Frequency Boost
The high-frequency boost available in the MAX7444
compensates for signal degradation and rolloff in the
video encoder, which increases the image sharpness.
The MAX7443 has a flat response over the video bandwidth.
Output Buffer
The output buffer drives two 150Ω video loads with a
2VP-P signal. The adjustable gain of the output buffer
provides a gain of 6dB, 9.5dB, and 12dB, which are
selected by tying the GSET pin to GND, VCC, or floating, respectively. The MAX7443/MAX7444 can drive an
AC load or drive the video load directly without using
the large output capacitor. The output buffer drives a
DC load with an output blanking level of less than 1V.
_______________________________________________________________________________________
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
GSET
GAIN (dB)
PART
HIGH-FREQUENCY BOOST
No
GND
6
MAX7443ETA
VCC
9.5
MAX7443ESA
No
12
MAX7444ETA
Yes
MAX7444ESA
Yes
Open
12dB Gain Setting
The GSET pin is biased internally to VCC/2 through two
100kΩ resistors from VCC to GND. The internal impedance at the node is 50kΩ. No additional connection is
necessary since the pin offers a minimum noise margin
immunity of 1VP-P.
Output Clamp Level
When sync pulses in the luma signal (Y) are detected,
the DC restore loop is activated. The function of the
loop is to set the sync tip of the video signal to the
desired DC level of 0.8V for YOUT and COUT and the
average DC voltage of COUT at 1.6V.
Pin Configurations
TOP VIEW
YIN
1
GSET
2
CIN
3
GND
4
MAX7443
MAX7444
8
YOUT
7
CVOUT
6
COUT
5
VCC
8
YOUT
7
CVOUT
6
COUT
5
VCC
Applications Information
THIN QFN
Input Considerations
Use a 0.1µF ceramic capacitor to AC-couple the input
to the MAX7443/MAX7444. This input capacitor stores
a DC level such that the outputs are clamped to the
appropriate DC voltage level.
Output Considerations
The outputs of the MAX7443/MAX7444 are typically
connected to a 75Ω series back-match resistor followed by the video cable. Because of the inherent
divide by two of this configuration, the blanking level of
the video cable is always less than 1V, which complies
with industry-standard video requirements. The video
buffer can also drive an AC-coupled video load. Good
video performance is achieved with an output capacitor
as low as 220µF.
Power-Supply Bypassing and Layout
The MAX7443/MAX7444 operate from a single +5V
supply. Bypass VCC to GND with a 0.1µF capacitor.
Place all external components as close to the device as
possible. Refer to the MAX7443 evaluation kit for a
proven PC board layout example.
YIN
1
GSET
2
CIN
3
GND
4
MAX7443
MAX7444
SO
Chip Information
TRANSISTOR COUNT: 4252
PROCESS: BiCMOS
Exposed Pads
Both the SO and thin QFN packages of the MAX7443/
MAX7444 have exposed pads on the bottom of the
packages. These pads are electrically connected to
GND and should be connected to the ground plane for
improved thermal conductivity. Do not route signals
under these packages.
_______________________________________________________________________________________________________
5
MAX7443/MAX7444
Selector Guide
Table 1. Gain-Setting Control
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
8L, SOIC EXP. PAD.EPS
MAX7443/MAX7444
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
6
_______________________________________________________________________________________
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
6, 8, &10L, QFN THIN.EPS
PACKAGE OUTLINE, 6, 8 & 10L,
QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm
21-0137
C
_______________________________________________________________________________________
7
MAX7443/MAX7444
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX7443/MAX7444
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
COMMON DIMENSIONS
SYMBOL
A
MIN.
MAX.
0.70
0.80
D
2.90
3.10
E
2.90
3.10
A1
0.00
0.05
L
k
0.20
0.40
0.25 MIN
A2
0.20 REF.
PACKAGE VARIATIONS
PKG. CODE
N
D2
E2
e
JEDEC SPEC
b
T633-1
6
1.50–0.10
2.30–0.10
0.95 BSC
MO229 / WEEA
0.40–0.05
1.90 REF
T833-1
8
1.50–0.10
2.30–0.10
0.65 BSC
MO229 / WEEC
0.30–0.05
1.95 REF
T1033-1
10
1.50–0.10
2.30–0.10
0.50 BSC
MO229 / WEED-3
0.25–0.05
2.00 REF
[(N/2)-1] x e
PACKAGE OUTLINE, 6, 8 & 10L,
QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm
21-0137
C
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.