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19-3482; Rev 0; 10/04
KIT ATION EVALU LE B AVAILA
HD/SD Switchable Video Filters and Buffers
General Description
The MAX7454/MAX7455 triple-channel video reconstruction filters and buffers are ideal for high definition (HD), standard definition progressive scan/noninterlaced (SDp), and standard definition interlaced (SDi) television applications. These devices are a fully integrated solution for filtering and buffering HD and/or SDp/SDi TV signals in component video output format (Y PB PR or RGB). The MAX7454/MAX7455 are compatible with the 1080i, 720p, 480p, and 480i scanning system standards. In addition to having an HD/SD switchable frequency response, the magnitude response can be optimized by approximately 15% by a control input. The input and output signals are DC-coupled to the MAX7454/MAX7455, eliminating the large output AC-coupling capacitors normally used. The MAX7454/MAX7455 output buffers drive a 2VP-P video signal into a standard 150 load. The MAX7454 has a gain of +6dB and the MAX7455 has a gain of +12dB. Both devices are available in a 20-pin TSSOP package and are fully specified over the upper commercial (0C to +85C) temperature range.
Features
30MHz High Definition (HD)/10MHz Standard Definition (SD) Switchable Video Reconstruction Filter 15% Magnitude Response Adjustment Passband: -2.3dB at 30MHz -0.40dB at 10MHz -0.10dB at 5MHz Stopband: -55dB at 74MHz (HDTV) -62dB at 27MHz (SDTV) Output Blank Level <1V for DC-Coupled Output +6dB Gain (MAX7454) or +12dB Gain (MAX7455) Direct Coupled Input, Zero Tilt Direct Coupled Output, No Large Output Capacitor Drives 2VP-P Signal in 150 Video Load Small 20-Pin TSSOP Package Single +5V Supply
MAX7454/MAX7455
Applications
Set-Top Boxes Direct-Broadcast Satellite (DBS) Receiver DVD Players Hard-Disk Recorders HDTV (LCD, PDP, DLP) Professional Cameras
Pin Configuration appears at end of data sheet.
PART MAX7454UUP MAX7455UUP*
Ordering Information
TEMP RANGE PIN-PACKAGE BUFFER GAIN (dB) +6 +6 +12 +12
0C to +85C 20 TSSOP-EP** 0C to +85C 20 TSSOP-EP**
MAX7454UUP+* 0C to +85C 20 TSSOP-EP** MAX7455UUP+* 0C to +85C 20 TSSOP-EP** +Indicates lead-free packaging. *Future product--contact factory for availability. **EP = Exposed pad.
Typical Operating Circuit
+5V VCC
MAX7454/MAX7455
ENCODER Y/R D/A IN1 SWITCHABLE LOWPASS FILTER +6dB OR +12dB OUT1 75 ZO = 75 75 2 D/A Pb/G IN2 SWITCHABLE LOWPASS FILTER +6dB OR +12dB OUT2 75 ZO = 75 75 2 D/A Pr/B IN3 SWITCHABLE LOWPASS FILTER +6dB OR +12dB OUT3 75 ZO = 75 75 FSEL SD/HD GND
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HD/SD Switchable Video Filters and Buffers MAX7454/MAX7455
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.3V to +6V IN1, IN2, IN3 to GND..................................-0.3V to (VCC + 0.3V) OUT1, OUT2, OUT3 to GND ......................-0.3V to (VCC + 0.3V) SD/HD, FSEL to GND .................................-0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70C) 20-Pin TSSOP (derate 21.7mW/C above +70C) .....1739.1mW Maximum Current into IN1, IN2, IN3, SD/HD, FSEL .........50mA Operating Temperature Range MAX745_UUP .....................................................0C to +85C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C Junction Temperature ......................................................+150C
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%, RLOAD = 150 to GND, CLOAD = 0 to 20pF to GND, SD/HD = GND, FSEL = VCC, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25C.)
PARAMETERS HD-Filter Passband Response HD-Filter Stopband Attenuation SD-Filter Passband Response SD-Filter Stopband Attenuation HD Group Delay Deviation HD Group Delay Matching tG tG(MATCH) SYMBOL APB ASB CONDITIONS f = 100kHz to 26MHz, FSEL = GND f = 100kHz to 26MHz, FSEL = VCC f = 100kHz to 30MHz, FSEL = VCC f = 74MHz, FSEL = GND f = 10MHz, SD/HD = VCC, FSEL = VCC f = 27MHz, SD/HD = VCC, FSEL = GND 100kHz to 26MHz, relative to 100kHz; FSEL = VCC Channel to channel, 100kHz to 2MHz; FSEL = VCC 100kHz to 5.75MHz, relative to 100kHz; SD/HD = VCC, FSEL = VCC 100kHz to 10MHz, relative to 100kHz; SD/HD = VCC, FSEL = VCC Channel to channel, 100kHz to 500kHz; FSEL = VCC Gain = +2V/V, VOUT = 2VP-P video signal 100kHz to 26MHz 5-step modulated staircase (Note 1) 5-step modulated staircase (Note 1) Output signal (2VP-P) to RMS noise (100kHz to 30MHz) Deviations in a line with an 18s, 100 IRE bar (Note 2) MAX7454, THD > -30dB, fIN = 4.43MHz MAX7455, THD > -30dB, fIN = 4.43MHz MAX7454, VIN = 0.3V, FSEL = GND VDIST SD/HD = VCC SD/HD = GND 0 0 -0.25 -0.25 1 62 MIN -3.5 -2.6 -3.6 45 -0.65 50 TYP -2.5 -1.7 -2.3 55 -0.40 62 5 0.1 2 ns 12 2 -45 0.3 0.2 67 1 3 1.2 0.6 +0.25 +0.25 10 ns dB % Degrees dB mV V mV mV dB dB dB ns ns dB MAX UNITS
SD Group Delay Deviation
tG
SD Group Delay Matching Total Harmonic Distortion Differential Gain Differential Phase Signal-to-Noise Ratio Line Time Distortion Input Voltage Range Total Output DC Variation Field Time Distortion
tG(MATCH) THD dG d SNR HDIST
130 lines, 18s, 100 IRE bars
2
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HD/SD Switchable Video Filters and Buffers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V 5%, RLOAD = 150 to GND, CLOAD = 0 to 20pF to GND, SD/HD = GND, FSEL = VCC, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25C.)
PARAMETERS Input Leakage Current Input Capacitance Low-Frequency Gain Accuracy Low-Frequency Gain Matching Dynamic Output Swing Channel-to-Channel Isolation Power-Supply Rejection Ratio Supply Voltage Range Supply Current LOGIC INPUTS (SD/HD, FSEL) Input High Voltage Input Low Voltage Input Current VIH VIL Digital inputs = VCC or 0V 2.4 0.8 10 V V A PSRR VCC ICC No load SYMBOL IIN CIN fIN = 100kHz fIN = 100kHz, maximum difference between any two input channels THD > -30dB DC to 1MHz VIN = 100mVP-P at 5MHz VIN =10mVP-P at 26MHz 4.75 2.4 70 35 25 5 220 5.25 235 -2.5 0 CONDITIONS MIN TYP 10 5 +2.5 1.2 MAX UNITS nA pF % % VP-P dB dB V mA
MAX7454/MAX7455
Note 1: The differential gain and differential phase specifications apply to standard-definition composite video signals only. Note 2: This applies for an anti-aliasing filtering application using a 0.1F input capacitor. This does not apply for a video reconstruction application, since there is no input-coupling capacitor.
Typical Operating Characteristics
(RLOAD = 150 to GND, VCC = +5V, and TA = +25C.)
MAGNITUDE RESPONSE (PASSBAND PLUS STOPBAND)
MAX7454toc01
GROUP DELAY
90 80 70 DELAY (ns)
MAX7454 toc02
10 0 -10 RESPONSE (dB) -20 HDHI -30 -40 -50 -60 -70 -80 0.1 1 10 FREQUENCY (MHz) 100 SDLO HDLO SDHI
100
60 50 40 30 20 10 HDHI SDHI
1000
0 0.1 1 10 100 FREQUENCY (MHz)
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HD/SD Switchable Video Filters and Buffers MAX7454/MAX7455
Typical Operating Characteristics (continued)
(RLOAD = 150 to GND, VCC = +5V, and TA = +25C.)
2T RESPONSE (1 IRE = 7.14mV)
MAX7454 toc03
MODULATED 12.5T RESPONSE (1 IRE = 7.14mV)
MAX7454 toc04
200mV/div
200mV/div
200mV/div
200mV/div
200ns/div
400ns/div
DIFFERENTIAL GAIN (%)
SUPPLY CURRENT vs. TEMPERATURE
MAX7454 toc05
DIFFERENTIAL GAIN
0.1 0 -0.1 -0.2 1 0.2 0.1 0 -0.1 -0.2 1 2 3 4 5 6 7 2 3 4 5 6 7
MAX7454 toc06
0.30 0.28 0.26 SUPPLY CURRENT (A) 0.24 0.22 0.20 0.18 0.16 0.14 0.12 0.10 -40 -15 10 35 60 HDLO SDLO HDHI
0.2
85
TEMPERATURE (C)
4
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DIFFERENTIAL PHASE (deg)
DIFFERENTIAL PHASE
HD/SD Switchable Video Filters and Buffers
Pin Description
PIN 1, 3, 5, 7, 11, 12, 15, 18 2 4 6 8 9 10, 13, 16, 19 14 17 20 -- NAME GND IN1 IN2 IN3 SD/HD FSEL VCC OUT3 OUT2 OUT1 EP Ground Video Input 1 Video Input 2 Video Input 3 SD/HD Select. Selects between HD or SD magnitude response. Connect to GND to choose HD bandwidth response. Frequency Select. Selects either a low or high setting for both HD and SD frequency response (see the Frequency Adjusting section). +5V Power Supply. Bypass to GND with a 0.1F capacitor. See the Power-Supply Bypassing and Layout Considerations section. Video Output 3 Video Output 2 Video Output 1 Exposed Pad. The exposed pad is internally connected to ground. FUNCTION
MAX7454/MAX7455
Detailed Description
The MAX7454/MAX7455 are ideal for use in consumer electronic products such as HD-compatible cable-TV set-top boxes or DBS receiver decoders, which process video signals in component output format. The MAX7454/MAX7455 support both the 1080i and the 720p scanning formats for HDTV as well as the 480i and 480p formats for SDi and SDp TV. The reconstruction filters take three signals out of a video digital-to-analog converter (DAC) or an encoder and smooth the signals with appropriate filtering. FSEL and SD/HD select the filter frequency response for SDp, SDi, and HDTV (see Table 1). The outputs are connected directly to standard 150 video loads. The Typical Operating Circuit illustrates the internal structure of the MAX7454/MAX7455. The lowpass filter attenuates the high-frequency contents of the input, and the output amplifier drives a standard video load.
Table 1. Frequency Selection Control
MODE HD Low HD High SD Low SD High SD/HD GND GND VCC VCC FSEL GND VCC GND VCC
frequencies of 74MHz and above for HDTV (see the Typical Operating Characteristics). Frequency Adjusting SD/HD selects the HD or SD mode. In HD or SD mode, FSEL allows optimization of the passband or stopband performance by adjusting the cutoff frequency. If passband performance is the priority, set FSEL high for the maximum passband performance with a small compromise in stopband attenuation. If stopband performance is more important, set FSEL low for the maximum stopband attenuation with a small compromise in passband. Due to the steep transition band response, the MAX7454/MAX7455 can be used in both progressive scan and interlaced video signals. The stopband attenuation at 27MHz or higher is >62dB.
Filter
Filter response The video filter features an elliptic-type response with a steep transition band response to achieve a wider passband response along with an excellent stopband response. In addition, the filter has been optimized to give a good time domain response with low overshoot. The stopband offers 62dB (typ) of attenuation at sampling frequencies of 27MHz and above for SDTV and 55dB (typ) of stopband attenuation for
Output Buffer
The output buffer on the MAX7454/MAX7455 drives a 2VP-P signal into a 150 video load. It is intended to be DC-coupled per the digital TV standard. No output AC-
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HD/SD Switchable Video Filters and Buffers MAX7454/MAX7455
coupling capacitors are required when driving a cable, thereby eliminating the normal adverse effects caused by these large capacitors. The output DC level is controlled to limit the DC voltage on the cable so the blanking level of the video signal is always less than 1V, meeting the digital TV specification. See the Output DC Level section for more information. The output of the MAX7454/MAX7455 can also be ACcoupled when driving a high-impedance load. In antialiasing applications, when the optimum bias point for the converter needs to be established, the MAX7454/ MAX7455 can drive a high impedance (typ >1k) through an AC-coupling capacitor. Gain Options The MAX7454 features an overall gain of +6dB, while the MAX7455 features an overall gain of +12dB. Output DC Level The MAX7454/MAX7455 are DC-coupled circuits. The nominal DC or nominal instantaneous AC voltage on the outputs of the MAX7454/MAX7455 can be determined by the following equations: VOUT = 2 x VIN + 0.8V (MAX7454) VOUT = 4 x VIN + 0.8V (MAX7455) For example, in the MAX7454, 0V on the input results in an output nominal voltage of 0.8V, and a 0.3V input (typical blanking level) results in an output nominal level of 1.4V.
Output Considerations
The outputs of the MAX7454/MAX7455 are normally DC-coupled. No AC-coupling capacitors are required. The MAX7454/MAX7455 connect directly to the video cable with a 75 series termination resistor. The other end of the cable should also be properly terminated with a 75 resistor. Because of the inherent divide-bytwo of this configuration the peak-to-peak amplitude as well as the DC level of the signal are divided by two. The biasing on the output of the MAX7454/MAX7455 is such that the blanking level of the video signal on the cable is always less than 1V, which complies with digital TV requirements.
Anti-Aliasing Filter
The MAX7454/MAX7455 can be used as an anti-aliasing filter to eliminate out-of-band noise in an analog-todigital video-sampling system. The output of the MAX7454/MAX7455 can be DC- or AC-coupled. This decision depends on the input range of the analog-todigital converter and the required accuracy of the resulting digital blanking level. The output blanking level of the MAX7454/MAX7455 is 1.4V with the negative peak of the signal at 0.8V and the positive peak white at 2.8V. This assumes a 1VP-P input signal with the negative peak at 0V. See the Electrical Characteristics table for the specified variations of these values. If the DC and peak levels are not compatible with the data-converter input, the outputs of the MAX7454/MAX7455 need to be AC-coupled. Choose an AC-coupling capacitor value that ensures that the lowest frequency content in the video signal is passed and the line time distortion is kept within desired limits. The resulting capacitor value is dependent on the input impedance of the converter circuit. Use a video clamp to re-establish the DC level.
Applications Information
Input Considerations
The inputs on the MAX7454/MAX7455 are normally DCcoupled. Thus, no AC-coupling capacitors are required. The input voltage range includes ground and typically extends up to 1.2V. If the input is from a typical single supply current output DAC or encoder it can be connected directly to the MAX7454/MAX7455. The board trace should be kept as short as possible to minimize the parasitic stray capacitance. The MAX7454/ MAX7455 contribute 5pF of capacitance. For example, a total capacitance on the input of approximately 20pF causes a 100MHz pole if the DAC termination resistor is 75. A pole at 100MHz introduces an additional 0.5dB passband attenuation at 30MHz. The input to the MAX7454/MAX7455 can be AC-coupled. In this case, it is important to set the DC bias properly to ensure that the negative peak of the video signal is as near to zero volts as possible. The bias can be fixed or a video clamp can be used. A video clamp is preferable because it limits the total swing of the signal by holding the blanking level of the signal constant.
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Power-Supply Bypassing and Layout Considerations
The MAX7454/MAX7455 operate from a single +5V supply. Bypass each VCC to GND with a 0.1F capacitor and an additional 1F capacitor in parallel if any significant low-frequency disturbances are present in the vicinity of the MAX7454/MAX7455. Use an extensive ground plane to ensure optimum performance. The three VCC pins (pins 13, 16, and 19) that supply the individual channels can be connected together and bypassed as one, provided the components are close to the pins. Bypass the remaining V CC pin (pin 10) separately with the same 0.1F and 1F capacitor combination. Place the input and output termination resistors as close to the device as possible. Alternatively, the terminations may be placed further from the device if the PC board
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HD/SD Switchable Video Filters and Buffers
traces are designed to be a controlled impedance of 75. Regardless, the parasitic capacitance should be kept as low as possible to avoid performance degradation in the frequency response at 30MHz. Refer to the MAX7454/MAX7455 evaluation kit for a proven PC board layout. One tested board is a 4-layer board using FR-4 material and 1oz copper. It has equal areas of metal on the top side and bottom side that coincide with the plastic encapsulated area of the 20-pin TSSOP package. The two middle layers are power and ground planes. The board has 21 15-mil plated-through via holes between the top, bottom, and ground plane layers. This board was measured and has a total thermal resistance of 25C/W, less than the 30C/W goal.
MAX7454/MAX7455
Exposed Pad and Heat Dissipation
The TSSOP package of the MAX7454/MAX7455 has an exposed pad on its bottom. This pad is electrically connected to GND. Do not route signals under the package. Heat dispersion is a very important issue for the MAX7454/MAX7455. The design of the PC board area associated with and in the vicinity of the device is important in achieving an adequate thermal resistance to keep the temperature of the MAX7454/MAX7455 within the specified limits. The thermal resistance of the 20-pin TSSOP package is 60C/W from die to ambient in free air. The thermal resistance from the die to the package surface (case) is 2C/W. The net thermal resistance on a practical board is between these two numbers. The typical power dissipation of the MAX7454/MAX7455 is 1.2W. To keep the die temperature within specified limits, the maximum net thermal resistance should not exceed 30C/W. This value is calculated assuming a worst-case ambient temperature of +85C and the maximum die temperature. The use of a 2-layer board with a good ground plane is recommended. Place copper directly under the MAX7454/MAX7455 package so that it matches the outline of the plastic encapsulated area. Place via holes in this area to electrically and thermally connect it to the ground plane. Use as many vias as possible for maximum heat transfer.
Pin Configuration
TOP VIEW
GND 1 IN1 2 GND 3 IN2 4 GND 5 IN3 6 GND 7 SD/HD 8 FSEL 9 VCC 10 20 OUT1 19 VCC 18 GND 17 OUT2
MAX7454 MAX7455
16 VCC 15 GND 14 OUT3 13 VCC 12 GND 11 GND
TSSOP
Chip Information
TRANSISTOR COUNT: 19191 PROCESS: BiCMOS
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HD/SD Switchable Video Filters and Buffers MAX7454/MAX7455
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.)
XX XX
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY, EXPOSED PAD
21-0108
E
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
TSSOP 4.4mm BODY.EPS

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