MAXIM MAX7448 Technical data

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General Description

The MAX7448, 4-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.

The MAX7448 processes RGB and asynchronous CVBS
video signals. The output video buffers have a fixed gain
of +6dB. The channel used for CVBS video has high-fre­quency boost circuitry, which provides picture sharpness
with +1.2dB of gain boost without degradation in the
stopband. The output video drivers can be disabled with
an external pin.

The MAX7448 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.

Applications

Set-Top Boxes/HDRs DVD Players

Game Consoles Digital VCRs

Desktop Video Editors

Features

♦ 4-Channel Filter and Buffer for RGB and CVBS

Video Signals

♦ Filter Response Ideal for NTSC, PAL, and

Interlaced SDTV Video Signals

♦ 43dB (typ) Stopband Attenuation at 27MHz

♦ ±0.75dB (max) Passband Ripple Out to 5MHz

♦ Blanking Level Voltage on Cable <1V

♦ Each Channel Drives Two 150Ω Video Loads

♦ +5V Single-Supply Voltage

♦ Small 14-Pin TSSOP Package

MAX7448

4-Channel RGB Video Filter with

Asynchronous CVBS Input

________________________________________________________________ Maxim Integrated Products 1

Functional Diagram

Ordering Information

19-2989; Rev 0; 10/03

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.

*EP = Exposed pad.

EVALUATION KIT

AVAILABLE

Pin Configuration appears at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX7448EUD -40°C to +85°C 14 TSSOP-EP*

*

*

*

*

*

*

*

*

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

(WITH SYNC)

CVBS

(WITH SYNC)

ENCODER

G

D/A

D/A

R

D/A

B

D/A

0.1µF

0.1µF

0.1µF

0.1µF

INA

INB

INC

IND

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

V

CC

SYNC

DETECTOR

SYNC

DETECTOR

MAX7448

GND

DISABLE

OUTA

OUTB

OUTC

OUTD

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

75Ω

*OPTIONAL CAPACITORS

MAX7448

4-Channel RGB Video Filter with
Asynchronous CVBS Input

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +5V ±5%, CL= 0 to 20pF, RL= 75Ω to GND for DC-coupled load, RL= 75Ω to VCC/ 2 for AC-coupled load, C

IN_

= 0.1µF,

GAIN = +6dB,T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V, TA= +25°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.

VCCto GND ...........................................................................+6V

All Other Pins to GND.................................-0.3V to (V

CC

+ 0.3V)

Maximum Current into Any Pin Except V

CC

and GND .....±50mA

Continuous Power Dissipation (T

A

= +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

)

Passband Response

Stopband Attenuation A

Differential Gain dG 5-step modulated staircase 0.15 0.50 %

Differential Phase dθ 5-step modulated staircase 0.15 0.50 Degrees

Signal-to-Noise Ratio SNR

Group Delay Deviation ∆tg

Line-Time Distortion H

Field-Time Distortion V

Clamp Settling Time t

Output DC Clamp Level

Low-Frequency Gain Accuracy A

Low-Frequency Gain Matching A

Group Delay Matching

Channel-to-Channel Crosstalk X

Output Short-Circuit Current I

Input Leakage Current I

Input Dynamic Swing

SUPPLY

Supply Voltage Range V

Supply Current I

Power-Supply Rejection Ratio PSRR V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

f = 100kHz to 5MHz,
relative to 100kHz

f ≥ 27MHz 39 43 dB

SB

Peak signal (2V
f = 100Hz to 50MHz

Deviation from 100kHz
to 4.1MHz

DIST

DIST

CLAMP

V(MATCH

g(MATCH)

t

TALK

SC

CC

CC

18µs, 100 IRE bar 0.3 %

130 lines, 18µs, 100 IRE bar 0.5 %

To ±1% 100 Lines

Channels A, D 0.6 0.9 1.1

Channels B, C 1.1 1.5 1.8

f = 100kHz -3 +3 %

V

Low-frequency channel-to-channel
matching, f = 100kHz

Low-frequency channel-to-channel
matching, f = 100kHz

f = 100kHz to 3.58MHz 60 dB

OUT_ shorted to GND or V

IN

Channels A, D 1.2

Channels B, C 0.9

No load 100 140 mA

= 100mV

IN

Channels A, B, C +0.75 +0.15 +0.75

Channel D +0.9 +1.2 +1.5

) to RMS noise,

P-P

Channels A, B, C 11 20

Channel D 17 30

CC

4.75 5.25 V

, f = 0 to 3.5MHz 40 dB

P-P

80 dB

4%

2ns

70 mA

10 µA

dB

ns

V

V

P-P

MAX7448

4-Channel RGB Video Filter with

Asynchronous CVBS Input

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +5V ±5%, CL= 0 to 20pF, RL= 75Ω to GND for DC-coupled load, RL= 75Ω to VCC/ 2 for AC-coupled load, C

IN_

= 0.1µF,

GAIN = +6dB, T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V, TA= +25°C.)

Typical Operating Characteristics

(VCC= +5V, TA = +25°C, unless otherwise noted.)

AMPLITUDE vs. FREQUENCY

MAX7448 toc01

FREQUENCY (MHz)

AMPLITUDE (dB)

10

-80

-60

-40

-20

0

1 100

NORMALIZED TO 0dB

PASSBAND AMPLITUDE vs. FREQUENCY

FREQUENCY (MHz)

AMPLITUDE (dB)

1

-1.5

-1.0

-0.5

0

0.5

1.0

1.5

2.0

-2.0

0.1 10

MAX7448 toc02

NORMALIZED TO 0dB

FLAT PASSBAND RESPONSE

HIGH-FREQUENCY BOOST

PHASE RESPONSE vs. FREQUENCY

MAX7448 toc03

FREQUENCY (MHz)

PHASE (DEGREES)

1

-150

-100

-50

0

50

100

150

200

-200

0.1 10

DISABLE

Output Impedance during
Disable

Disable Logic-Input High Voltage V

Disable Logic-Input Low Voltage V

Disable Logic-Input Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Z

DISABLE

DISABLEVIL

At 5MHz 2 kΩ

IH

IL

= 0V (sink), VIH = V

(source) ±10 µA

CC

2.0 V

0.8 V