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19-2990; Rev 0; 9/03
KIT ATION EVALU ILABLE AVA
3-Channel Video Reconstruction Filter for RGB Component Video
General Description Features
o 3-Channel Filter and Buffer for RGB Video Signals o External Sync Signal Input o Filter Response Ideal for NTSC, PAL, and Interlaced SDTV Video Signals o 43dB (typ) Stopband Attenuation at 27MHz o 0.75dB (max) Passband Ripple at 5MHz o Blanking Level Voltage on Output <1V o Each Channel Drives Two 150 Video Loads o +5V Single-Supply Voltage o Small 14-Pin TSSOP Package
MAX7449
The MAX7449, 3-channel, buffered video reconstruction filter is ideal for anti-aliasing and digital-to-analog converter (DAC)-smoothing video applications or wherever analog video is reconstructed from a digital data stream (such as cable/satellite/terrestrial set-top boxes, DVD players, hard-disk recorders (HDRs), and personal video recorders (PVRs)). This device operates from a single +5V supply and has a flat passband out to 5MHz with a stopband attenuation of 43dB at 27MHz. This makes it ideal for use with NTSC, PAL, and standarddefinition digital TV (SDTV) video systems. Each output is capable of driving two standard 150 video loads. The MAX7449 processes component RGB video signals. The output video buffers have a fixed gain of +6dB. The output video drivers can be disabled with an external pin. The MAX7449 is available in a 14-pin TSSOP package with an exposed pad, and is specified over the -40C to +85C extended temperature range.
Ordering Information
PART TEMP RANGE -40C to +85C PIN-PACKAGE 14 TSSOP-EP* MAX7449EUD
Applications
Set-Top Boxes/HDRs Desktop Video Editors Digital VCRs Game Consoles DVD Players
*EP = Exposed pad.
Pin Configuration appears at end of data sheet.
Functional Diagram
VCC ENCODER 75 0.1F R D/A * INA LOWPASS FILTER OUTA 75 * 75 75
75 0.1F G D/A * INB LOWPASS FILTER OUTB 75 *
75 75
75 0.1F B D/A INC LOWPASS FILTER OUTC 75
* *
75 75
MAX7449
GND EXTSYNC DISABLE
*OPTIONAL CAPACITORS
________________________________________________________________ Maxim Integrated Products
1
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3-Channel Video Reconstruction Filter for RGB Component Video MAX7449
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 = +70C) TSSOP-EP (derate 20.8mW/C above +70C) ...........1667mW Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Junction Temperature ......................................................+150C Lead Temperature (soldering, 10s) .................................+300C
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 = +4.75V to +5.25V, CL = 0 to 20pF, RL = 75 to GND for DC-coupled load, RL = 75 to VCC / 2 for AC-coupled load, CIN_ = 0.1F, GAIN = +6dB, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25C.)
PARAMETER Passband Response Stopband Attenuation Differential Gain Differential Phase Signal-to-Noise Ratio Group Delay Deviation Line-Time Distortion Field-Time Distortion Clamp Settling Time Output DC Clamp Level Low-Frequency Gain Accuracy Low-Frequency Gain Matching Group Delay Matching Channel-to-Channel Crosstalk Output Short-Circuit Current Input Leakage Current Input Dynamic Swing SUPPLY Supply Voltage Range Supply Current Power-Supply Rejection Ratio VCC ICC PSRR No load VIN = 100mVP-P, f = 0 to 3.5MHz 4.75 75 40 5.25 100 V mA dB AV ASB dG d SNR tg HDIST VDIST tCLAMP SYMBOL CONDITIONS f = 100kHz to 5MHz, relative to 100kHz, channels A, B, C f 27MHz 5-step modulated staircase 5-step modulated staircase Peak signal (2VP-P) to RMS noise, f = 100Hz to 50MHz Deviation from 100kHz to 4.1MHz 18s, 100 IRE bar 130 lines, 18s, 100 IRE bar To 1% Channels A, B, C f = 100kHz Low-frequency channel-to-channel AV(MATCH) matching, f = 100kHz tg(MATCH) XTALK ISC IIN Channels A, B, C Low-frequency channel-to-channel matching, f = 100kHz f = 100kHz to 3.58MHz OUT_ shorted to GND or VCC 2 60 70 10 0.9 1.1 -3 1.5 MIN -0.75 39 TYP +0.15 43 0.15 0.15 80 11 20 0.3 0.5 100 1.8 +3 4 0.50 0.50 MAX +0.75 UNITS dB dB % Degrees dB ns % % Lines V % % ns dB mA A VP-P
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3-Channel Video Reconstruction Filter for RGB Component Video
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +4.75V to +5.25V, CL = 0 to 20pF, RL = 75 to GND for DC-coupled load, RL = 75 to VCC / 2 for AC-coupled load, CIN_ = 0.1F, GAIN = +6dB, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25C.)
PARAMETER Output Impedance During Disable Logic-Input High Voltage Logic-Input Low Voltage Logic Input Current SYMBOL ZDISABLE VIH VIL ILOGIC VIL = 0V (SINK), VIH = VCC (SOURCE) At 5MHz 2.0 0.8 10 CONDITIONS MIN TYP 2 MAX UNITS k V V A LOGIC INPUTS (DISABLE and EXTSYNC)
MAX7449
Typical Operating Characteristics
(VCC = +5V, TA = +25C, unless otherwise noted.)
AMPLITUDE vs. FREQUENCY
MAX7449 toc01
PASSBAND AMPLITUDE vs. FREQUENCY
MAX7449 toc02
PHASE RESPONSE vs. FREQUENCY
150 100 PHASE (DEGREES) 50 0 -50 -100 -150
MAX7449 toc03
2.0 1.5 1.0
200
0
AMPLITUDE (dB)
AMPLITUDE (dB) NORMALIZED TO 0dB
-20
0.5 0 -0.5 -1.0 -1.5
-40
-60
-80 1 10 FREQUENCY (MHz) 100
NORMALIZED TO 0dB -2.0 0.1 1 FREQUENCY (MHz) 10
-200 0.1 1 FREQUENCY (MHz) 10
GROUP DELAY vs. FREQUENCY
MAX7449 toc04
2T RESPONSE (1 IRE = 7.14mV)
MAX7449 toc05
MODULATED 12.5T RESPONSE (1 IRE = 7.14mV)
MAX7449 toc06
100
90 GROUP DELAY (ns)
IN_ 250mV/div
IN_
80
250mV/div
70 OUT_ OUT_ 60 250mV/div 50 0.1 1 FREQUENCY (MHz) 10 200ns/div 400ns/div 250mV/div
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3-Channel Video Reconstruction Filter for RGB Component Video MAX7449
Typical Operating Characteristics (continued)
(VCC = +5V, TA = +25C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MAX7449 toc07
DIFFERENTIAL GAIN
DIFFERENTIAL PHASE (DEGREES) DIFFERENTIAL GAIN (%) 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 1st 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 1st 2nd 3rd 4th 5th 6th 2nd 3rd 4th 5th 6th
MAX7449 toc08
120 INPUTS BIASED TO +2V NO LOAD SUPPLY CURRENT (mA) 110
100
DIFFERENTIAL PHASE
90
80 -40 -15 10 35 60 85 TEMPERATURE (C)
Pin Description
PIN 1, 10 2 3 4 5 6 7, 8 9, 14 11 12 13 NAME VCC INA INB INC DISABLE EXTSYNC GND N.C. OUTC OUTB OUTA +5V Supply Input Channel A Video Input. Use channel A for the red (R) video signal. AC-couple INA with a series 0.1F capacitor. Channel B Video Input. Use channel B for the green (G) video signal. AC-couple INB with a series 0.1F capacitor. Channel C Video Input. Use channel C for the blue (B) video signal. AC-couple INC with a series 0.1F capacitor. Disable Logic Input. Connect DISABLE to GND for normal operation. Connect DISABLE to VCC to disable all buffer outputs and put them in a high-impedance state. External Sync Input. Use TTL logic levels. A logic high enables the DC restore loop and clamps the output voltages to +1.5V (typ). Ground No Connection. Make no connection to these pins. Channel C Buffer Output. This output can be either AC- or DC-coupled. Channel B Buffer Output. This output can be either AC- or DC-coupled. Channel A Buffer Output. This output can be either AC- or DC-coupled. FUNCTION
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3-Channel Video Reconstruction Filter for RGB Component Video
Detailed Description
The MAX7449 filters and buffers video-encoder DAC outputs in applications such as set-top boxes, HDRs, DVD players, and digital VCRs. The MAX7449 reconstructs and cleans up component RGB analog video signals. Each channel consists of a lowpass filter and an output video buffer that drives two standard 150 video loads. This device operates from a single +5V supply and has a nominal cutoff frequency of 5MHz optimized for NTSC, PAL, and SDTV.
Applications Information
Input Considerations
Use 0.1F ceramic capacitors to AC-couple the inputs. These input capacitors store a DC level so the outputs are clamped to an appropriate DC voltage level. The MAX7449 allows R, G, or B video signals to be processed by any channel. G must not have sync information.
MAX7449
Output Considerations
The outputs are typically connected to a 75 series back-match resistor followed by the video cable. Because of the inherent divide-by-two of this configuration, the voltage on the video cable is always less than 1V, complying with industry-standard video requirements such as the European SCART standard (which allows up to 2V of DC on the video cable). The video buffer can also drive an AC-coupled video load. Good video performance is achieved with an output capacitor as low as 220F.
Filter
Filter Response The reconstruction filter consists of two 2nd-order SallenKey stages. The Butterworth-type response features a maximally flat passband for NTSC and PAL bandwidths. The stopband offers at least 43dB (typ) of attenuation at a sampling frequency of 27MHz (see the Typical Operating Characteristics).
Power-Supply Bypassing and Layout
The MAX7449 operates from a single +5V supply. Bypass VCC to GND with a 0.1F capacitor. Place all external components as close to the device as possible.
Output Buffers
Each output buffer has a fixed gain of +6dB and can drive two 150 video loads with a 2VP-P signal. The MAX7449 can drive an AC load or drive the video load directly without using a large output capacitor. The output buffers drive DC loads with an output blanking level of less than 1V.
Exposed Pads
The TSSOP-EP package has an exposed pad on the bottom of the package. This pad is electrically connected to GND and should be connected to the ground plane for improved thermal conductivity. Do not route signals under this package.
Output Clamp Level
When a sync pulse is detected on EXTSYNC, the DC restore loop is activated for channels A, B, and C. The function of the loop is to set the DC level of the video signal to the desired level. See Table 1 for clamp levels.
Pin Configuration
TOP VIEW
Table 1. Output Clamp Level
CHANNEL A B C CLAMP LEVEL (V) 1.5 1.5 1.5
VCC 1 INA INB 2 3
14 N.C. 13 OUTA 12 OUTB
INC 4 DISABLE 5 EXTSYNC 6 GND 7
MAX7449
11 OUTC 10 VCC 9 8 N.C. GND
TSSOP
Chip Information
TRANSISTOR COUNT: 6300 PROCESS: BiCMOS
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3-Channel Video Reconstruction Filter for RGB Component Video MAX7449
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.)
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY EXPOSED PAD
21-0108
C
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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.
6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
TSSOP 4.4mm BODY.EPS

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