MAXIM MAX7455UUP

19-3482; Rev 0; 10/04
KIT
ATION
EVALU
E
L
B
AVAILA
HD/SD Switchable Video Filters and Buffers
Features
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
150Ω 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 (0°C to +85°C) temperature range.
♦ 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 150Ω Video Load
♦ Small 20-Pin TSSOP Package
♦ Single +5V Supply
Ordering Information
Applications
Set-Top Boxes
TEMP
RANGE
PART
Direct-Broadcast Satellite (DBS) Receiver
PIN-PACKAGE
BUFFER
GAIN (dB)
0°C to +85°C 20 TSSOP-EP**
+6
DVD Players
MAX7454UUP+* 0°C to +85°C 20 TSSOP-EP**
+6
Hard-Disk Recorders
MAX7455UUP*
0°C to +85°C 20 TSSOP-EP**
+12
HDTV (LCD, PDP, DLP)
MAX7455UUP+* 0°C to +85°C 20 TSSOP-EP**
+Indicates lead-free packaging.
*Future product—contact factory for availability.
**EP = Exposed pad.
+12
MAX7454UUP
Professional Cameras
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
+5V
VCC
MAX7454/MAX7455
ENCODER
Y/R
D/A
IN1
SWITCHABLE
LOWPASS
FILTER
+6dB OR
+12dB
OUT1
75Ω
ZO = 75Ω
75Ω
2
D/A
Pb/G
IN2
SWITCHABLE
LOWPASS
FILTER
+6dB OR
+12dB
OUT2
75Ω
ZO = 75Ω
75Ω
2
D/A
Pr/B
IN3
SWITCHABLE
LOWPASS
FILTER
+6dB OR
+12dB
OUT3
75Ω
ZO = 75Ω
75Ω
FSEL
SD/HD
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
MAX7454/MAX7455
General Description
MAX7454/MAX7455
HD/SD Switchable Video Filters and Buffers
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 = +70°C)
20-Pin TSSOP (derate 21.7mW/°C above +70°C) .....1739.1mW
Maximum Current into IN1, IN2, IN3, SD/HD, FSEL .........±50mA
Operating Temperature Range
MAX745_UUP .....................................................0°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Junction Temperature ......................................................+150°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%, RLOAD = 150Ω 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 = +25°C.)
PARAMETERS
SYMBOL
HD-Filter Passband Response
APB
HD-Filter Stopband Attenuation
ASB
MIN
TYP
f = 100kHz to 26MHz, FSEL = GND
CONDITIONS
-3.5
-2.5
f = 100kHz to 26MHz, FSEL = VCC
-2.6
-1.7
f = 100kHz to 30MHz, FSEL = VCC
-3.6
-2.3
f = 74MHz, FSEL = GND
45
MAX
UNITS
dB
55
dB
SD-Filter Passband Response
f = 10MHz, SD/HD = VCC, FSEL = VCC
-0.65
-0.40
dB
SD-Filter Stopband Attenuation
f = 27MHz, SD/HD = VCC, FSEL = GND
50
62
dB
HD Group Delay Deviation
∆tG
100kHz to 26MHz, relative to 100kHz;
FSEL = VCC
5
ns
HD Group Delay Matching
tG(MATCH)
Channel to channel, 100kHz to 2MHz;
FSEL = VCC
0.1
ns
SD Group Delay Deviation
∆tG
SD Group Delay Matching
tG(MATCH)
Total Harmonic Distortion
THD
Differential Gain
dG
Differential Phase
dθ
Signal-to-Noise Ratio
SNR
Line Time Distortion
HDIST
Input Voltage Range
2
2
100kHz to 10MHz, relative to 100kHz;
SD/HD = VCC, FSEL = VCC
12
Channel to channel, 100kHz to 500kHz;
FSEL = VCC
2
ns
Gain = +2V/V, VOUT = 2VP-P video signal
100kHz to 26MHz
-45
dB
5-step modulated staircase (Note 1)
0.3
%
5-step modulated staircase (Note 1)
0.2
Degrees
67
dB
Output signal (2VP-P) to RMS noise (100kHz
to 30MHz)
VDIST
ns
62
Deviations in a line with an 18µs, 100 IRE
bar (Note 2)
±1
±3
MAX7454, THD > -30dB, fIN = 4.43MHz
0
1.2
MAX7455, THD > -30dB, fIN = 4.43MHz
0
0.6
SD/HD = VCC
-0.25
+0.25
SD/HD = GND
-0.25
+0.25
MAX7454, VIN = 0.3V,
FSEL = GND
Total Output DC Variation
Field Time Distortion
100kHz to 5.75MHz, relative to 100kHz;
SD/HD = VCC, FSEL = VCC
130 lines, 18µs, 100 IRE bars
±1
_______________________________________________________________________________________
±10
mV
V
mV
mV
HD/SD Switchable Video Filters and Buffers
(VCC = +5V ±5%, RLOAD = 150Ω 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 = +25°C.)
PARAMETERS
SYMBOL
Input Leakage Current
IIN
Input Capacitance
CIN
CONDITIONS
MIN
MAX
UNITS
±10
fIN = 100kHz
Low-Frequency Gain Matching
fIN = 100kHz, maximum difference between
any two input channels
Dynamic Output Swing
THD > -30dB
Channel-to-Channel Isolation
DC to 1MHz
PSRR
Supply Voltage Range
VCC
Supply Current
ICC
nA
5
Low-Frequency Gain Accuracy
Power-Supply Rejection Ratio
TYP
-2.5
0
pF
+2.5
%
1.2
%
2.4
VP-P
70
VIN = 100mVP-P at 5MHz
35
VIN =10mVP-P at 26MHz
25
4.75
No load
dB
dB
5
5.25
V
220
235
mA
LOGIC INPUTS (SD/HD, FSEL)
Input High Voltage
VIH
Input Low Voltage
VIL
2.4
Input Current
V
Digital inputs = VCC or 0V
0.8
V
±10
µA
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 0.1µF input capacitor. This does not apply for a video reconstruction application, since there is no input-coupling capacitor.
Typical Operating Characteristics
(RLOAD = 150Ω to GND, VCC = +5V, and TA = +25°C.)
MAGNITUDE RESPONSE
(PASSBAND PLUS STOPBAND)
90
-10
80
-20
70
DELAY (ns)
HDHI
-30
SDHI
-40
-50
MAX7454 toc02
0
RESPONSE (dB)
GROUP DELAY
100
MAX7454toc01
10
60
50
SDHI
40
30
-60
-70
10
HDLO
-80
0.1
1
10
FREQUENCY (MHz)
HDHI
20
SDLO
100
1000
0
0.1
1
10
100
FREQUENCY (MHz)
_______________________________________________________________________________________
3
MAX7454/MAX7455
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(RLOAD = 150Ω to GND, VCC = +5V, and TA = +25°C.)
MODULATED 12.5T RESPONSE
(1 IRE = 7.14mV)
2T RESPONSE (1 IRE = 7.14mV)
MAX7454 toc04
MAX7454 toc03
200mV/div
200mV/div
200mV/div
200mV/div
400ns/div
200ns/div
0.26
0.24
HDHI
0.22
0.2
0.1
0
-0.1
-0.2
1
0.18
SDLO
0.16
0.14
0.12
0.10
-40
-15
10
35
60
85
DIFFERENTIAL PHASE (deg)
HDLO
0.20
MAX7454 toc06
MAX7454 toc05
0.28
DIFFERENTIAL GAIN (%)
DIFFERENTIAL GAIN
SUPPLY CURRENT vs. TEMPERATURE
0.30
SUPPLY CURRENT (A)
MAX7454/MAX7455
HD/SD Switchable Video Filters and Buffers
2
3
4
5
6
7
6
7
DIFFERENTIAL PHASE
0.2
0.1
0
-0.1
-0.2
1
2
3
4
5
TEMPERATURE (°C)
4
_______________________________________________________________________________________
HD/SD Switchable Video Filters and Buffers
PIN
NAME
FUNCTION
1, 3, 5, 7, 11,
12, 15, 18
GND
2
IN1
Video Input 1
4
IN2
Video Input 2
6
IN3
Video Input 3
8
SD/HD
9
FSEL
Frequency Select. Selects either a low or high setting for both HD and SD frequency response (see
the Frequency Adjusting section).
10, 13, 16,
19
VCC
+5V Power Supply. Bypass to GND with a 0.1µF capacitor. See the Power-Supply Bypassing and
Layout Considerations section.
14
OUT3
Video Output 3
17
OUT2
Video Output 2
20
OUT1
—
EP
Ground
SD/HD Select. Selects between HD or SD magnitude response. Connect to GND to choose HD
bandwidth response.
Video Output 1
Exposed Pad. The exposed pad is internally connected to ground.
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
150Ω 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.
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
Table 1. Frequency Selection Control
SD/HD
FSEL
HD Low
MODE
GND
GND
HD High
GND
VCC
SD Low
VCC
GND
SD High
VCC
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.
Output Buffer
The output buffer on the MAX7454/MAX7455 drives a
2VP-P signal into a 150Ω video load. It is intended to be
DC-coupled per the digital TV standard. No output AC-
_______________________________________________________________________________________
5
MAX7454/MAX7455
Pin Description
MAX7454/MAX7455
HD/SD Switchable Video Filters and Buffers
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 >1kΩ)
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.
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
75Ω. 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.
6
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 75Ω series termination resistor. The other
end of the cable should also be properly terminated
with a 75Ω 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.
Power-Supply Bypassing and Layout
Considerations
The MAX7454/MAX7455 operate from a single +5V
supply. Bypass each VCC to GND with a 0.1µF capacitor and an additional 1µF 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 0.1µF and 1µF 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
_______________________________________________________________________________________
HD/SD Switchable Video Filters and Buffers
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
60°C/W from die to ambient in free air. The thermal resistance from the die to the package surface (case) is
2°C/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 30°C/W. This value
is calculated assuming a worst-case ambient temperature of +85°C 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.
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
25°C/W, less than the 30°C/W goal.
Pin Configuration
TOP VIEW
GND 1
20 OUT1
IN1 2
19 VCC
GND 3
18 GND
IN2 4
GND 5
IN3 6
17 OUT2
MAX7454
MAX7455
GND 7
16 VCC
15 GND
14 OUT3
SD/HD 8
13 VCC
FSEL 9
12 GND
VCC 10
11 GND
TSSOP
Chip Information
TRANSISTOR COUNT: 19191
PROCESS: BiCMOS
_______________________________________________________________________________________
7
MAX7454/MAX7455
traces are designed to be a controlled impedance of
75Ω. 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.
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.)
TSSOP 4.4mm BODY.EPS
MAX7454/MAX7455
HD/SD Switchable Video Filters and Buffers
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
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.