MAXIM MAX7449EUD

19-2990; Rev 0; 9/03
KIT
ATION
EVALU
E
L
B
A
IL
AVA
3-Channel Video Reconstruction Filter
for RGB Component Video
Features
♦ 3-Channel Filter and Buffer for RGB Video Signals
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 -40°C to
+85°C extended temperature range.
♦ External Sync Signal Input
♦ Filter Response Ideal for NTSC, PAL, and
Interlaced SDTV Video Signals
♦ 43dB (typ) Stopband Attenuation at 27MHz
♦ ±0.75dB (max) Passband Ripple at 5MHz
♦ Blanking Level Voltage on Output <1V
♦ Each Channel Drives Two 150Ω Video Loads
♦ +5V Single-Supply Voltage
♦ Small 14-Pin TSSOP Package
Ordering Information
PART
Applications
Set-Top Boxes/HDRs
Game Consoles
Desktop Video Editors
DVD Players
MAX7449EUD
TEMP RANGE
PIN-PACKAGE
-40°C to +85°C
14 TSSOP-EP*
*EP = Exposed pad.
Digital VCRs
Pin Configuration appears at end of data sheet.
Functional Diagram
VCC
ENCODER
75Ω
75Ω
0.1µF
R
D/A
*
INA
OUTA
LOWPASS
FILTER
75Ω
*
75Ω
75Ω
0.1µF
G
D/A
*
INB
OUTB
LOWPASS
FILTER
75Ω
75Ω
0.1µF
B
D/A
75Ω
INC
OUTC
LOWPASS
FILTER
MAX7449
75Ω
*
*
*
75Ω
75Ω
75Ω
*OPTIONAL CAPACITORS
GND
EXTSYNC
DISABLE
________________________________________________________________ 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
MAX7449
General Description
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 150Ω video loads.
MAX7449
3-Channel Video Reconstruction Filter
for RGB Component Video
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)
TSSOP-EP (derate 20.8mW/°C above +70°C) ...........1667mW
Operating Temperature Range ...........................-40°C to +85°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 = +4.75V to +5.25V, CL = 0 to 20pF, RL = 75Ω to GND for DC-coupled load, RL = 75Ω to VCC / 2 for AC-coupled load, CIN_ =
0.1µF, GAIN = +6dB, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25°C.)
PARAMETER
SYMBOL
Passband Response
CONDITIONS
MIN
TYP
MAX
UNITS
f = 100kHz to 5MHz, relative to 100kHz,
channels A, B, C
-0.75
+0.15
+0.75
dB
39
43
Stopband Attenuation
ASB
f ≥ 27MHz
Differential Gain
dG
dθ
5-step modulated staircase
0.15
0.50
%
5-step modulated staircase
0.15
0.50
Degrees
Differential Phase
Signal-to-Noise Ratio
Group Delay Deviation
Line-Time Distortion
SNR
Peak signal (2VP-P) to RMS noise,
f = 100Hz to 50MHz
80
∆tg
Deviation from 100kHz to 4.1MHz
11
dB
dB
20
ns
0.3
%
HDIST
18µs, 100 IRE bar
Field-Time Distortion
VDIST
130 lines, 18µs, 100 IRE bar
0.5
%
Clamp Settling Time
tCLAMP
To ±1%
100
Lines
1.8
V
+3
%
4
%
Output DC Clamp Level
Low-Frequency Gain Accuracy
AV
Channels A, B, C
1.1
f = 100kHz
-3
Low-Frequency Gain Matching
Low-frequency channel-to-channel
AV(MATCH)
matching, f = 100kHz
Group Delay Matching
tg(MATCH)
Channel-to-Channel Crosstalk
XTALK
Output Short-Circuit Current
ISC
Input Leakage Current
IIN
Input Dynamic Swing
Low-frequency channel-to-channel
matching, f = 100kHz
1.5
2
ns
f = 100kHz to 3.58MHz
60
dB
OUT_ shorted to GND or VCC
70
mA
Channels A, B, C
10
µA
0.9
VP-P
SUPPLY
Supply Voltage Range
VCC
Supply Current
ICC
Power-Supply Rejection Ratio
2
PSRR
4.75
No load
75
VIN = 100mVP-P, f = 0 to 3.5MHz
40
_______________________________________________________________________________________
5.25
V
100
mA
dB
3-Channel Video Reconstruction Filter
for RGB Component Video
(VCC = +4.75V to +5.25V, CL = 0 to 20pF, RL = 75Ω to GND for DC-coupled load, RL = 75Ω to VCC / 2 for AC-coupled load, CIN_ =
0.1µF, GAIN = +6dB, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V, TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
LOGIC INPUTS (DISABLE and EXTSYNC)
Output Impedance During Disable
ZDISABLE
Logic-Input High Voltage
VIH
Logic-Input Low Voltage
VIL
Logic Input Current
At 5MHz
2
kΩ
2.0
ILOGIC
V
VIL = 0V (SINK), VIH = VCC (SOURCE)
0.8
V
±10
µA
Typical Operating Characteristics
(VCC = +5V, TA = +25°C, unless otherwise noted.)
200
MAX7449 toc02
MAX7449 toc01
0
PHASE RESPONSE vs. FREQUENCY
PASSBAND AMPLITUDE vs. FREQUENCY
2.0
1.5
150
100
-40
-60
0.5
0
-0.5
-50
-100
-150
NORMALIZED TO 0dB
10
0
-1.0
-200
-2.0
1
50
-1.5
NORMALIZED TO 0dB
-80
0.1
100
0.1
10
1
10
1
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
GROUP DELAY vs. FREQUENCY
2T RESPONSE (1 IRE = 7.14mV)
MODULATED 12.5T RESPONSE
(1 IRE = 7.14mV)
MAX7449 toc05
MAX7449 toc04
100
90
GROUP DELAY (ns)
PHASE (DEGREES)
AMPLITUDE (dB)
AMPLITUDE (dB)
1.0
-20
MAX7449 toc03
AMPLITUDE vs. FREQUENCY
80
MAX7449 toc06
IN_
IN_
250mV/div
250mV/div
70
OUT_
OUT_
60
250mV/div
250mV/div
50
0.1
1
10
200ns/div
400ns/div
FREQUENCY (MHz)
_______________________________________________________________________________________
3
MAX7449
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VCC = +5V, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
INPUTS BIASED TO +2V
NO LOAD
110
100
90
80
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
MAX7449 toc08
DIFFERENTIAL PHASE (DEGREES) DIFFERENTIAL GAIN (%)
DIFFERENTIAL GAIN
MAX7449 toc07
120
SUPPLY CURRENT (mA)
MAX7449
3-Channel Video Reconstruction Filter
for RGB Component Video
1st
2nd
3rd
4th
5th
6th
DIFFERENTIAL PHASE
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
1st
2nd
3rd
4th
5th
6th
Pin Description
4
PIN
NAME
FUNCTION
1, 10
VCC
+5V Supply Input
2
INA
Channel A Video Input. Use channel A for the red (R) video signal. AC-couple INA with a series 0.1µF capacitor.
3
INB
Channel B Video Input. Use channel B for the green (G) video signal. AC-couple INB with a series 0.1µF
capacitor.
4
INC
Channel C Video Input. Use channel C for the blue (B) video signal. AC-couple INC with a series 0.1µF
capacitor.
5
DISABLE
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.
6
EXTSYNC
External Sync Input. Use TTL logic levels. A logic high enables the DC restore loop and clamps the output
voltages to +1.5V (typ).
7, 8
GND
Ground
9, 14
N.C.
No Connection. Make no connection to these pins.
11
OUTC
Channel C Buffer Output. This output can be either AC- or DC-coupled.
12
OUTB
Channel B Buffer Output. This output can be either AC- or DC-coupled.
13
OUTA
Channel A Buffer Output. This output can be either AC- or DC-coupled.
_______________________________________________________________________________________
3-Channel Video Reconstruction Filter
for RGB Component Video
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).
Output Buffers
Each output buffer has a fixed gain of +6dB and can
drive two 150Ω 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.
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.
Applications Information
Input Considerations
Use 0.1µF 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.
Output Considerations
The outputs 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 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 220µF.
Power-Supply Bypassing and Layout
The MAX7449 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.
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.
Pin Configuration
TOP VIEW
Table 1. Output Clamp Level
14 N.C.
VCC 1
CLAMP LEVEL (V)
INA
2
13 OUTA
A
1.5
INB
3
12 OUTB
B
1.5
INC 4
C
1.5
CHANNEL
MAX7449
DISABLE 5
11 OUTC
10 VCC
EXTSYNC 6
9
N.C.
GND 7
8
GND
TSSOP
Chip Information
TRANSISTOR COUNT: 6300
PROCESS: BiCMOS
_______________________________________________________________________________________
5
MAX7449
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 150Ω
video loads.
This device operates from a single +5V supply and has
a nominal cutoff frequency of 5MHz optimized for
NTSC, PAL, and SDTV.
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
MAX7449
3-Channel Video Reconstruction Filter
for RGB Component Video
PACKAGE OUTLINE, TSSOP, 4.40 MM BODY
EXPOSED PAD
21-0108
C
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.
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© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.