MAXIM MAX7453CSA

19-3269; Rev 0; 6/05
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
The MAX7453 is a low-cost, triple-channel video reconstruction filter for S-video and CVBS video-signal applications. This device is ideal for anti-aliasing and DAC
smoothing video applications such as set-top boxes,
DVD players, hard-disk recorders (HDRs), and personal
video recorders. This filter operates from a single +5V
supply. It is optimized for NTSC, PAL, and standard-definition TV (SDTV) video systems.
Each channel consists of a lowpass filter and an output
buffer capable of driving one (YOUT, COUT) or two
(CVOUT) 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 MAX7453 has a maximally flat frequency response.
The MAX7453 is available in an 8-pin SO package and is
fully specified over the commercial (0°C to +70°C) temperature range.
Features
♦ Triple-Channel Filter and Buffer for CVBS and
Y/C (S-Video) Video Signals
♦ Filter Response Ideal for NTSC, PAL, and
Interlaced SDTV Signals
♦ 42dB (typ) Stopband Attenuation at 27MHz
♦ -0.3dB (typ) Passband Response
♦
♦
♦
♦
♦
<1V Blanking Level Allows DC-Coupled Output
CVOUT Drives Two 150Ω Video Loads
YOUT and COUT Drive One 150Ω Video Load
+5V Single-Supply Voltage
8-Pin SO Package
Ordering Information
PART
TEMP RANGE
MAX7453CSA
0°C to +70°C
Applications
PIN-PACKAGE
8 SO
Pin Configuration
Set-Top Boxes/HDRs/DVDs
TOP VIEW
Security Cameras/Digital Cameras
YIN 1
Game Consoles
8
YOUT
7
VCC
3
6
CVOUT
CIN 4
5
COUT
N.C. 2
MAX7453
Digital VCRs
GND
Every Composite, S-Video Output for NTSC,
PAL, and SDTV
SO
Functional Diagram
VCC
*
ENCODER
D/A
YIN
LOWPASS
FILTER
+6dB
YOUT
*
MAX7453
D/A
CIN
LOWPASS
FILTER
Σ
+6dB
+6dB
CVOUT
*
COUT
*
GND
________________________________________________________________ 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
MAX7453
General Description
MAX7453
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 SO ....................................................................522.8mW
Operating Temperature Range...............................0°C to +70°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, all loads to GND for DC-couple, all loads to VCC / 2 for AC-couple, CYIN = CCIN = 0.1µF,
RYOUT = 150Ω, RCOUT = 150Ω, RCVOUT = 75Ω, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Passband Response
Stopband Attenuation
CONDITIONS
MIN
TYP
MAX
UNITS
-0.6
-0.27
0
dB
f = 27MHz
39
42
f = 3.58MHz, reference to CVOUT at 336kHz
96
98
100
%
f = 100kHz to 4.2MHz, relative to 100kHz
ASB
Chroma/Luma Gain
dB
Differential Gain
dG
5-step modulated staircase
0.15
0.5
%
Differential Phase
dθ
5-step modulated staircase
0.15
0.5
Degrees
Signal-to-Noise Ratio
SNR
Peak signal (2VP-P) to RMS noise,
f = 100Hz to 50MHz
Line-Time Distortion
HDIST
18µs, 100IRE bar
0.3
Field-Time Distortion
VDIST
130 lines, 18µs, 100IRE bar
0.5
Clamp Settling Time
67
To ±1%
Output DC Clamp Level
73
dB
300
%
%
Lines
YOUT
0.60
0.8
0.95
CVOUT
0.60
0.8
0.95
COUT
1.44
1.6
1.95
-3.0
V
Low-Frequency Gain Accuracy
AV
f = 100kHz, relative to 6dB
Group-Delay Deviation
∆tg
Deviation from 100kHz to 4.1MHz
8
Group-Delay Matching
tg(MATCH)
Low-frequency channel-to-channel matching,
f = 100kHz for YOUT and COUT
2
ns
f = 100kHz to 3.58MHz
61
dB
Channel-to-Channel Crosstalk
Input Leakage Current
Input Dynamic Swing
XTALK
+2.0
%
16
ns
IIN
10
YINP-P
1.2
CINP-P
0.9
µA
VP-P
SUPPLY
Supply Voltage Range
VCC
Supply Current
ICC
Power-Supply Rejection Ratio
2
PSRR
4.75
VCC = +5.25V, no load
65
VIN = 100mVP-P, f = 0 to 3.5MHz
33
_______________________________________________________________________________________
5.25
V
85
mA
dB
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
AMPLITUDE vs. FREQUENCY
PASSBAND AMPLITUDE vs. FREQUENCY
0
0
-30
-40
-50
-40
PHASE (DEGREES)
AMPLITUDE (dB)
-20
-0.5
-1.0
-1.5
-2.0
-120
-160
-240
NORMALIZED TO 0dB
NORMALIZED TO 0dB
-80
-3.0
10
1
-80
-200
-2.5
-70
MAX7453 toc03
0.5
-60
100
-280
0.1
10
1
FREQUENCY (MHz)
FREQUENCY (MHz)
GROUP DELAY vs. FREQUENCY
2T RESPONSE (1IRE = 7.4mV)
0.1
1
MODULATED 12.5T RESPONSE
(1IRE = 7.14mV)
MAX7453 toc06
MAX7453 toc04
85
80
10
FREQUENCY (MHz)
MAX7453 toc05
90
GROUP DELAY (ns)
PHASE RESPONSE vs. FREQUENCY
40
MAX7453 toc02
0
-10
AMPLITUDE (dB)
1.0
MAX7453 toc01
10
MAX7453
Typical Operating Characteristics
(VCC = +5V, TA = +25°C, unless otherwise noted.)
MEASURE AT TERMINATION
75
YIN
500mV/div
70
YIN
200mV/div
65
60
55
YOUT
500mV/div
MEASURE AT
TERMINATION
50
YOUT
200mV/div
45
40
0.1
10
1
100ns/div
400ns/div
FREQUENCY (MHz)
SUPPLY CURRENT (mA)
64
62
60
58
56
54
52
50
-40
-15
10
35
TEMPERATURE (°C)
60
85
MULTIBURST RESPONSE
DIFFERENTIAL GAIN
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
MAX7453 toc09
MAX7453 toc08
66
DIFFERENTIAL PHASE (DEGREES)
MAX7453 toc07
68
DIFFERENTIAL GAIN (%)
SUPPLY CURRENT vs. TEMPERATURE
70
1st
2nd
3rd
4th
5th
YIN
500mV/div
6th
MEASURED AT TERMINATION
DIFFERENTIAL PHASE
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
YOUT
500mV/div
10µs/div
1st
2nd
3rd
4th
5th
6th
_______________________________________________________________________________________
3
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
MAX7453
Pin Description
PIN
NAME
1
YIN
Luma (Y) Input
FUNCTION
2
N.C.
No Connection. No internal connection.
3
GND
Ground
4
CIN
Chroma (C) Input
5
COUT
6
CVOUT
7
VCC
5V Power Supply
8
YOUT
Luma (Y) Output
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 to
set the average DC voltage of COUT at 1.6V.
Applications Information
Chroma (C) Output
Input Considerations
Composite Video Output
Use a 0.1µF ceramic capacitor to AC-couple the input
to the MAX7453. This input capacitor stores a DC level
such that the outputs are clamped to the appropriate
DC voltage level.
Detailed Description
The primary function of the MAX7453 is to filter and
buffer the encoder DAC outputs that contain digital
video information in applications such as set-top boxes,
HDRs, DVD players, and digital VCRs. This device
reconstructs and cleans up analog video signals. The
MAX7453 consists of a lowpass filter and a +6dB-gain
output video buffer. The luma (YIN) and chroma (CIN)
video inputs are summed internally to provide the composite (CVOUT) video output.
These devices operate from a single +5V supply. The
filters have a nominal cutoff frequency optimized for
NTSC, PAL, and SDTV.
Filter
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 42dB (typ) of attenuation at sampling frequencies of 27MHz and above (see
the Typical Operating Characteristics).
Output Buffer
Output Considerations
The outputs of the MAX7453 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 MAX7453 operates 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.
The maximum power dissipation listed in the Absolute
Maximum Ratings section assumes that the PC board is
a multilayer board with ground and power planes.
Chip Information
TRANSISTOR COUNT: 4100
PROCESS: BiCMOS
The YOUT and COUT buffers have a fixed +6dB gain
capable of driving one standard 150Ω video load with a
2VP-P signal. The CVOUT buffer has a fixed +6dB gain,
capable of driving two 150Ω video loads. The MAX7453
can drive an AC load or drive the video load directly
without using the large output capacitor. The output
buffer of all the channels drives a DC load with an output blanking level of less than 1V.
4
_______________________________________________________________________________________
Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs
N
E
H
INCHES
MILLIMETERS
MAX
MIN
0.069
0.053
0.010
0.004
0.014
0.019
0.007
0.010
0.050 BSC
0.150
0.157
0.228
0.244
0.016
0.050
MAX
MIN
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
1.27 BSC
3.80
4.00
5.80
6.20
0.40
SOICN .EPS
DIM
A
A1
B
C
e
E
H
L
1.27
VARIATIONS:
1
INCHES
TOP VIEW
DIM
D
D
D
MIN
0.189
0.337
0.386
MAX
0.197
0.344
0.394
MILLIMETERS
MIN
4.80
8.55
9.80
MAX
5.00
8.75
10.00
N MS012
8
AA
14
AB
16
AC
D
C
A
B
e
0∞-8∞
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
21-0041
REV.
B
1
1
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
MAX7453
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.)