MAX7454UUP+ [ROCHESTER]
SPECIALTY CONSUMER CIRCUIT, PDSO20, 4.40 MM, LEAD FREE, MO-153ACT, TSSOP-20;
| 型号： | MAX7454UUP+ |
| 厂家： | 
Rochester Electronics |
| 描述： | SPECIALTY CONSUMER CIRCUIT, PDSO20, 4.40 MM, LEAD FREE, MO-153ACT, TSSOP-20 信息通信管理 光电二极管 商用集成电路 |
| 文件： | 总9页 (文件大小：916K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3482; Rev 1; 6/05
HD/SD Switchable Video Filters and Buffers
General Description
Features
The MAX7454/MAX7455 triple-channel video recon-
struction filters and buffers are ideal for high definition
(HD), standard definition progressive scan/noninter-
laced (SDp), and standard definition interlaced (SDi)
television applications. These devices are a fully inte-
grated solution for filtering and buffering HD and/or
SDp/SDi TV signals in component video output format
♦ 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)
(Y P P or RGB). The MAX7454/MAX7455 are compati-
B
R
ble 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.
♦ Output Blank Level <1V for DC-Coupled Output
♦ +6dB Gain (MAX7454) or +12dB Gain (MAX7455)
♦ Direct Coupled Input, Zero Tilt
The input and output signals are DC-coupled to the
MAX7454/MAX7455, eliminating the large output AC-cou-
pling capacitors normally used. The MAX7454/MAX7455
♦ Direct Coupled Output, No Large Output Capacitor
output buffers drive a 2V
video signal into a standard
P-P
♦ Drives 2V
Signal in 150Ω Video Load
P-P
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.
♦ Small 20-Pin TSSOP Package
♦ Single +5V Supply
Ordering Information
Applications
TEMP
RANGE
BUFFER
GAIN (dB)
Set-Top Boxes
PART
PIN-PACKAGE
Direct-Broadcast Satellite (DBS) Receiver
DVD Players
MAX7454UUP
0°C to +85°C 20 TSSOP-EP*
+6
+6
MAX7454UUP+ 0°C to +85°C 20 TSSOP-EP*
MAX7455UUP 0°C to +85°C 20 TSSOP-EP*
Hard-Disk Recorders
HDTV (LCD, PDP, DLP)
Professional Cameras
+12
+12
MAX7455UUP+ 0°C to +85°C 20 TSSOP-EP*
+Indicates lead-free packaging.
*EP = Exposed pad.
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
+5V
V
CC
MAX7454/MAX7455
ENCODER
75Ω
SWITCHABLE
LOWPASS
FILTER
Y/R
OUT1
OUT2
OUT3
IN1
IN2
IN3
+6dB OR
+12dB
D/A
D/A
D/A
Z = 75Ω
O
75Ω
2
2
75Ω
75Ω
SWITCHABLE
LOWPASS
FILTER
Pb/G
Pr/B
+6dB OR
+12dB
Z
O
= 75Ω
75Ω
SWITCHABLE
LOWPASS
FILTER
+6dB OR
+12dB
Z
O
= 75Ω
75Ω
FSEL
SD/HD
GND
________________________________________________________________ Maxim Integrated Products
1
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.
HD/SD Switchable Video Filters and Buffers
ABSOLUTE MAXIMUM RATINGS
CC
IN1, IN2, IN3 to GND..................................-0.3V to (V
OUT1, OUT2, OUT3 to GND ......................-0.3V to (V
SD/HD, FSEL to GND .................................-0.3V to (V
V
to GND..............................................................-0.3V to +6V
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
+ 0.3V)
+ 0.3V)
+ 0.3V)
CC
CC
CC
Continuous Power Dissipation (T = +70°C)
A
20-Pin TSSOP (derate 21.7mW/°C above +70°C) .....1739.1mW
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
(V
= +5V 5%, R
= 150Ω to GND, C
= 0 to 20pF to GND, SD/HD = GND, FSEL = V , T = T
to T
unless other-
MAX,
CC
LOAD
LOAD
CC
A
MIN
wise noted. Typical values are at V
= +5V and T = +25°C.)
CC
A
PARAMETERS
SYMBOL
CONDITIONS
MIN
TYP
-2.0
-1.7
-2.3
55
MAX
UNITS
f = 100kHz to 26MHz, FSEL = GND
-3.5
-2.6
-3.6
45
HD-Filter Passband Response
A
A
f = 100kHz to 26MHz, FSEL = V
f = 100kHz to 30MHz, FSEL = V
f = 74MHz, FSEL = GND
dB
PB
CC
CC
HD-Filter Stopband Attenuation
SD-Filter Passband Response
SD-Filter Stopband Attenuation
dB
dB
dB
SB
f = 10MHz, SD/HD = V , FSEL = V
-0.85
50
-0.40
62
CC
CC
f = 27MHz, SD/HD = V , FSEL = GND
CC
100kHz to 26MHz, relative to 100kHz;
HD Group Delay Deviation
HD Group Delay Matching
∆t
4
0.1
2
ns
ns
G
FSEL = V
CC
Channel to channel, 100kHz to 2MHz;
FSEL = V
t
t
G(MATCH)
CC
100kHz to 5.75MHz, relative to 100kHz;
SD/HD = V , FSEL = V
CC
100kHz to 10MHz, relative to 100kHz;
SD/HD = V , FSEL = V
CC
SD Group Delay Deviation
SD Group Delay Matching
Total Harmonic Distortion
∆t
ns
ns
G
12
2
CC
CC
Channel to channel, 100kHz to 500kHz;
FSEL = V
G(MATCH)
THD
CC
Gain = +2V/V, V
= 2V
video signal
OUT
P-P
-45
-53
100kHz to 26MHz
dB
Gain = +4V/V, V
= 2V
video signal
OUT
P-P
100kHz to 26MHz
Differential Gain
Differential Phase
dG
5-step modulated staircase (Note 1)
5-step modulated staircase (Note 1)
0.3
0.2
%
dθ
Degrees
Output signal (2V ) to RMS noise (100kHz
P-P
to 30MHz)
Signal-to-Noise Ratio
Line Time Distortion
Input Voltage Range
SNR
62
67
1
dB
mV
V
Deviations in a line with an 18µs, 100 IRE
bar (Note 2)
H
3
DIST
MAX7454, THD > -30dB, f = 4.43MHz
0
0
1.2
0.6
IN
MAX7455, THD > -30dB, f = 4.43MHz
IN
2
_______________________________________________________________________________________
HD/SD Switchable Video Filters and Buffers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +5V 5%, R
= 150Ω to GND, C
= 0 to 20pF to GND, SD/HD = GND, FSEL = V , T = T
to T
unless other-
MAX,
CC
LOAD
LOAD
CC
A
MIN
wise noted. Typical values are at V
= +5V and T = +25°C.)
CC
A
PARAMETERS
SYMBOL
CONDITIONS
= 0.3V for the
MIN
TYP
MAX
UNITS
V
IN
SD/HD = V
-0.25
-0.25
+0.25
CC
MAX7454 or V
=
IN
Total Output DC Variation
V
0.15V for the MAX7455,
FSEL = GND
SD/HD = GND
+0.25
10
Field Time Distortion
V
130 lines, 18µs, 100 IRE bars
1
10
5
mV
nA
pF
%
DIST
Input Leakage Current
Input Capacitance
I
IN
C
IN
Low-Frequency Gain Accuracy
f
f
= 100kHz
-2.5
2.4
+2.5
1.2
IN
= 100kHz, maximum difference between
any two input channels
IN
Low-Frequency Gain Matching
0
%
Dynamic Output Swing
THD > -30dB
DC to 1MHz
V
P-P
Channel-to-Channel Isolation
70
35
25
5
dB
V
V
= 100mV
at 5MHz
IN
IN
P-P
Power-Supply Rejection Ratio
PSRR
dB
=10mV
at 26MHz
P-P
Supply Voltage Range
Supply Current
V
4.75
2.4
5.25
240
V
CC
I
No load
220
mA
CC
LOGIC INPUTS (SD/HD, FSEL)
Input High Voltage
Input Low Voltage
V
V
V
IH
V
0.8
10
IL
Input Current
Digital inputs = V
or 0V
µA
CC
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 recon-
struction application, since there is no input-coupling capacitor.
Typical Operating Characteristics
(R
= 150Ω to GND, V
= +5V, and T = +25°C.)
CC A
LOAD
MAGNITUDE RESPONSE
(PASSBAND PLUS STOPBAND)
GROUP DELAY
10
0
100
90
80
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
HDHI
SDHI
SDHI
HDHI
SDLO
HDLO
0.1
1
10
100
1000
0.1
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
_______________________________________________________________________________________
3
HD/SD Switchable Video Filters and Buffers
Typical Operating Characteristics (continued)
(R
= 150Ω to GND, V
= +5V, and T = +25°C.)
CC A
LOAD
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
DIFFERENTIAL GAIN
SUPPLY CURRENT vs. TEMPERATURE
0.2
0.1
0
0.30
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
0.12
-0.1
-0.2
HDHI
1
2
3
4
5
6
7
HDLO
DIFFERENTIAL PHASE
0.2
0.1
0
SDLO
-0.1
-0.2
0.10
-40
1
2
3
4
5
6
7
-15
10
35
60
85
TEMPERATURE (°C)
4
_______________________________________________________________________________________
HD/SD Switchable Video Filters and Buffers
Pin Description
PIN
NAME
FUNCTION
1, 3, 5, 7, 11,
12, 15, 18
GND
Ground
2
4
6
IN1
IN2
IN3
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.
8
9
SD/HD
Frequency Select. Selects either a low or high setting for both HD and SD frequency response (see
the Frequency Adjusting section).
FSEL
10, 13, 16,
19
+5V Power Supply. Bypass to GND with a 0.1µF capacitor. See the Power-Supply Bypassing and
Layout Considerations section.
V
CC
14
17
20
—
OUT3
OUT2
OUT1
EP
Video Output 3
Video Output 2
Video Output 1
Exposed Pad. The exposed pad is internally connected to ground.
Table 1. Frequency Selection Control
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 fil-
ters 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 fil-
ter frequency response for SDp, SDi, and HDTV (see
Table 1). The outputs are connected directly to standard
150Ω video loads.
MODE
HD Low
SD/HD
GND
FSEL
GND
HD High
SD Low
SD High
GND
V
CC
V
V
GND
CC
CC
V
CC
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 pass-
band performance is the priority, set FSEL high for the
maximum passband performance with a small compro-
mise in stopband attenuation. If stopband performance
is more important, set FSEL low for the maximum stop-
band attenuation with a small compromise in passband.
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
Due to the steep transition band response, the
MAX7454/MAX7455 can be used in both progressive
scan and interlaced video signals. The stopband atten-
uation at 27MHz or higher is >62dB.
Output Buffer
The output buffer on the MAX7454/MAX7455 drives a
2V
signal into a 150Ω video load. It is intended to be
P-P
DC-coupled per the digital TV standard. No output AC-
_______________________________________________________________________________________
5
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.
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-by-
two 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 digi-
tal TV requirements.
The output of the MAX7454/MAX7455 can also be AC-
coupled when driving a high-impedance load. In anti-
aliasing 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.
Anti-Aliasing Filter
The MAX7454/MAX7455 can be used as an anti-alias-
ing filter to eliminate out-of-band noise in an analog-to-
digital 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-to-
digital converter and the required accuracy of the
resulting digital blanking level. The output blanking
level of the MAX7454/MAX7455 is 1.4V with the nega-
tive peak of the signal at 0.8V and the positive peak
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 deter-
mined by the following equations:
V
V
= 2 x V + 0.8V (MAX7454)
IN
OUT
OUT
white at 2.8V. This assumes a 1V
input signal with
P-P
= 4 x V + 0.8V (MAX7455)
IN
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 compat-
ible 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.
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 DC-
coupled. 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 typi-
cal 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 min-
imize 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.
Power-Supply Bypassing and Layout
Considerations
The MAX7454/MAX7455 operate from a single +5V
supply. Bypass each V
to GND with a 0.1µF capaci-
CC
tor and an additional 1µF capacitor in parallel if any sig-
nificant low-frequency disturbances are present in the
vicinity of the MAX7454/MAX7455. Use an extensive
ground plane to ensure optimum performance. The
three V
pins (pins 13, 16, and 19) that supply the
CC
individual channels can be connected together and
bypassed as one, provided the components are close
The input to the MAX7454/MAX7455 can be AC-cou-
pled. 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 sig-
nal by holding the blanking level of the signal constant.
to the pins. Bypass the remaining V
pin (pin 10)
CC
separately with the same 0.1µF and 1µF capacitor com-
bination.
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
6
_______________________________________________________________________________________
HD/SD Switchable Video Filters and Buffers
traces are designed to be a controlled impedance of
75Ω. Regardless, the parasitic capacitance should be
kept as low as possible to avoid performance degrada-
tion in the frequency response at 30MHz.
One tested board is a 4-layer board using FR-4 materi-
al 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.
Refer to the MAX7454/MAX7455 evaluation kit for a
proven PC board layout.
Exposed Pad and Heat Dissipation
The TSSOP package of the MAX7454/MAX7455 has an
exposed pad on its bottom. This pad is electrically con-
nected to GND. Do not route signals under the package.
Pin Configuration
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.
TOP VIEW
GND
IN1
1
2
20 OUT1
19
V
CC
GND
IN2
3
18 GND
17 OUT2
The thermal resistance of the 20-pin TSSOP package is
60°C/W from die to ambient in free air. The thermal resis-
tance 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 dissi-
pation 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 tempera-
ture of +85°C and the maximum die temperature.
4
MAX7454
MAX7455
GND
IN3
5
16
V
CC
6
15 GND
GND
SD/HD
FSEL
7
14
13
OUT3
8
V
CC
9
12 GND
11 GND
V
CC
10
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 maxi-
mum heat transfer.
TSSOP
Chip Information
TRANSISTOR COUNT: 19,191
PROCESS: BiCMOS
_______________________________________________________________________________________
7
HD/SD Switchable Video Filters and Buffers
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
1
E
21-0108
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
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
相关型号：
©2020 ICPDF网 联系我们和版权申明