MAXIM MAX7443, MAX7444 User Manual

General Description

The MAX7443/MAX7444 are low-cost, triple-channel
video reconstruction filters for S-video and CVBS video
signals. These devices are ideal for anti-aliasing and
DAC smoothing video applications such as set-top
boxes, DVD players, hard-disk recorders (HDRs), and
personal video recorders. These filters operate from a
single +5V supply. They are optimized for NTSC, PAL,
and standard-definition digital TV (SDTV) video systems.

Each channel consists of a lowpass filter and an
adjustable-gain output buffer capable of driving two
standard 150Ω video loads. The output buffers can drive
either an AC or a DC load such that the blanking level
voltage after the backmatch resistor is less than 1V. The
Y and C video inputs are summed to produce the com­posite video output. The MAX7444 offers high­frequency boost to improve picture sharpness. The
MAX7443 has a maximum flat-frequency response.

The MAX7443/MAX7444 are available in a tiny 8-pin thin
QFN and an 8-pin SO package with exposed pad, and
are fully specified over the -40°C to +85°C extended
temperature range.

Applications

Features

♦ Triple-Channel Filter and Buffer for CVBS and

Y/C (S-Video)

♦ Filter Response Ideal for NTSC, PAL, and

Interlaced SDTV Signals

♦ 41dB (typ) Stopband Attenuation at 27MHz

♦ -0.3dB (typ) Passband Response

♦ Low Blanking Level Voltage Allows DC-Coupled

Output

♦ Each Channel Drives Two 150Ω Video Loads

♦ +5V Single-Supply Voltage

♦ Tiny 8-Pin Thin QFN or 8-Pin SO Packages

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and

Buffer for Composite and Y/C Outputs

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2749; Rev 1; 1/06

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.

EVALUATION KIT

AVAILABLE

PART

PIN-PACKAGE

TOP

PKG

CODE

MAX7443ETA

AFX T833-1

MAX7443ESA 8 SO-EP* — S8E-12

MAX7444ETA

AFY T833-1

MAX7444ESA 8 SO-EP* — S8E-12

D/A

CIN

LOWPASS

FILTER

LOWPASS

FILTER

YIN

D/A

6dB/

9.5dB/
12dB

6dB/

9.5dB/
12dB

6dB/

9.5dB/
12dB

Σ

GSET

COUT

CVOUT

YOUT

*

*

*

*

*

*

*OPTIONAL

GND

V

CC

ENCODER

MAX7443
MAX7444

Functional Diagram

Set-Top Boxes/HDR/DVD

Security Cameras/Digital
Cameras

Game Consoles

Digital VCRs

Every Composite,
S-Video Output for NTSC,
PAL, SDTV

Note: All devices specified over -40°C to +85°C temperature
range.
*EP = Exposed pad.

Selector Guide appears at end of data sheet.

MARK

8 Thin QFN-EP*

8 Thin QFN-EP*

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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)
8-Pin Thin QFN (derate 24.4mW/°C above +70°C) ...1951mW

8-Pin SO (derate 18.9mW/°C above +70°C)..............1509mW

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

ELECTRICAL CHARACTERISTICS

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

YIN

= C

CIN

= 0.1µF,

T

A

= T

MIN

to T

MAX

, GSET = GND (6dB) and VCC(9.5dB), unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER

CONDITIONS

UNITS

MAX7443

Passband Response

f = 100kHz to 4.2MHz,
relative to 100kHz

MAX7444

dB

Stopband Attenuation A

SB

f = 27MHz 39 41 dB

Boost Amplitude f = 4.2MHz, MAX7444

dB

Differential Gain dG

5-step modulated
staircase

Gain = 6dB,

9.5dB, 12dB

%

Differential Phase dθ

5-step modulated
staircase

Gain = 6dB,

9.5dB, 12dB

Degrees

Signal-to-Noise Ratio SNR

Peak signal (2V

P-P

) to
RMS noise, f = 100Hz to
50MHz

Gain = 6dB,

9.5dB, 12dB

67 73 dB

MAX7443 8 20

Group Delay Deviation ∆t

g

Deviation from 100kHz to

4.1MHz

MAX7444 12 30

ns

Line-Time Distortion H

DIST

18µs, 100 IRE bar

%

Field-Time Distortion V

DIST

130 lines, 18µs, 100 IRE bar

%

Clamp Settling Time To ±1%

Lines

YOUT

CVOUT

Output DC Clamp Level

COUT

V

Low-Frequency Gain Accuracy A

V

f = 100kHz, relative to 6dB

+2 %

Group Delay Matching

f = 100kHz for YOUT and COUT

2ns

Channel-to-Channel Crosstalk X

TALK

f = 100kHz to 3.58MHz, gain = 6dB 61 dB

Input Leakage Current I

IN

10 µA

SYMBOL

MIN TYP MAX

-0.8 -0.3 +0.1

-0.1 +0.6 +0.92

0.6

0.15 0.4

tg(MATCH)

Low-frequency channel-to-channel matching,

0.6 0.8 1.0

0.6 0.8 1.0

1.44 1.6 1.97

-3.5

0.15 0.4

0.3

0.5

430

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and

Buffer for Composite and Y/C Outputs

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

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

YIN

= C

CIN

= 0.1µF,

T

A

= T

MIN

to T

MAX

, GSET = GND (6dB) and VCC(9.5dB), unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Y

INP-P

GSET = GND (6dB)

Input Dynamic Swing

C

INP-P

GSET = GND (6dB)

V

P-P

SUPPLY

Supply Voltage Range V

CC

V

Supply Current I

CC

VCC = +5.25V, no load 88

mA

Power-Supply Rejection Ratio PSRR V

IN

= 100mV

P-P

, f = 0 to 3.5MHz 33 dB

Typical Operating Characteristics

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

-80
1 10 100

AMPLITUDE vs. FREQUENCY

MAX7443/44 toc01

FREQUENCY (MHz)

AMPLITUDE (dB)

-60

-20

-40

0

NORMALIZED TO 0dB

-2.0

0.1 1 10

PASSBAND AMPLITUDE vs. FREQUENCY

MAX7443/44 toc02

FREQUENCY (MHz)

AMPLITUDE (dB)

0.5

-0.5

2.0

NORMALIZED TO 0dB

1.5

1.0

-1.5

-1.0

0

MAX7443

MAX7444

-200

0.1 1 10

PHASE RESPONSE vs. FREQUENCY

MAX7443/44 toc03

FREQUENCY (MHz)

PHASE (DEGREES)

50

-50

200

150

100

-150

-100

0

40

0.1 1 10

GROUP DELAY vs. FREQUENCY

MAX7443/44 toc04

FREQUENCY (MHz)

GROUP DELAY (ns)

70

60

90

80

50

2T RESPONSE (1 IRE = 7.14mV)

MAX7443/44 toc05

200ns/div

Y

IN

200mV/div

Y

OUT

400mV/div

MODULATED 12.5T RESPONSE

(1 IRE = 7.14mV)

MAX7443/44 toc06

400ns/div

Y

IN

200mV/div

Y

OUT

200mV/div

4.75 5.25

1.2

0.9

110

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs

4 _______________________________________________________________________________________

65

70

80

75

85

90

-40 10-15 35 60 85

SUPPLY CURRENT

vs. TEMPERATURE

MAX7443/44 toc07

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

DIFFERENTIAL GAIN

MAX7443/44 toc08

DIFFERENTIAL PHASE (DEGREES)

1324567

1324567

0.2

0.3

0.1
0

-0.1

-0.2

-0.3

DIFFERENTIAL GAIN (%)

0.2

0.3

0.1

0

-0.1

-0.2

-0.3

DIFFERENTIAL PHASE

MULTIBURST RESPONSE

MAX7443/44 toc09

YIN

200mV/div

YOUT

200mV/div

10µs/div

Typical Operating Characteristics (continued)

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

Detailed Description

The primary function of the MAX7443/MAX7444 is to fil­ter and buffer the encoder DAC outputs that contain
digital video information in applications such as set-top
boxes, hard-disk recorders, DVD players, and digital
VCRs. These devices reconstruct and clean up analog
video signals. Each MAX7443/MAX7444 consists of a
lowpass filter and an adjustable-gain output video
buffer that is capable of driving two standard 150Ω
video loads. The luma (YIN) and chroma (CIN) video
inputs are summed internally to provide the composite
(CVOUT) video output.

These devices operate from a single +5V supply. The
filters have a nominal cutoff frequency optimized for
NTSC, PAL, and SDTV.

Filter

Filter Response

The reconstruction filter consists of two 2nd-order
Sallen-Key stages. The Butterworth-type response fea­tures a maximally flat passband for NTSC and PAL
bandwidths. The stopband offers 41dB (typ) of attenua­tion at sampling frequencies of 27MHz and above (see
Typical Operating Characteristics).

High-Frequency Boost

The high-frequency boost available in the MAX7444
compensates for signal degradation and rolloff in the
video encoder, which increases the image sharpness.
The MAX7443 has a flat response over the video band­width.

Output Buffer

The output buffer drives two 150Ω video loads with a
2V

P-P

signal. The adjustable gain of the output buffer
provides a gain of 6dB, 9.5dB, and 12dB, which are
selected by tying the GSET pin to GND, VCC, or float­ing, respectively. The MAX7443/MAX7444 can drive an
AC load or drive the video load directly without using
the large output capacitor. The output buffer drives a
DC load with an output blanking level of less than 1V.

PIN

FUNCTION

1 YIN Luma (Y) Input

2 GSET

Gain-Setting Control Input. See Table 1
for values.

3 CIN Chroma (C) Input

4 GND Ground

5VCC5V Power Supply

6

Chroma (C) Output

7

Composite Video Output

8

Luma (Y) Output

Pin Description

NAME

COUT

CVOUT

YOUT

12dB Gain Setting

The GSET pin is biased internally to VCC/2 through two
100kΩ resistors from VCCto GND. The internal imped­ance at the node is 50kΩ. No additional connection is
necessary since the pin offers a minimum noise margin
immunity of 1V

P-P

.

Output Clamp Level

When sync pulses in the luma signal (Y) are detected,
the DC restore loop is activated. The function of the
loop is to set the sync tip of the video signal to the
desired DC level of 0.8V for YOUT and COUT and the
average DC voltage of COUT at 1.6V.

Applications Information

Input Considerations

Use a 0.1µF ceramic capacitor to AC-couple the input
to the MAX7443/MAX7444. This input capacitor stores
a DC level such that the outputs are clamped to the
appropriate DC voltage level.

Output Considerations

The outputs of the MAX7443/MAX7444 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 blanking level of
the video cable is always less than 1V, which complies
with industry-standard video requirements. 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 MAX7443/MAX7444 operate from a single +5V
supply. Bypass VCCto GND with a 0.1µF capacitor.
Place all external components as close to the device as
possible. Refer to the MAX7443 evaluation kit for a
proven PC board layout example.

Exposed Pads

Both the SO and thin QFN packages of the MAX7443/
MAX7444 have exposed pads on the bottom of the
packages. These pads are electrically connected to
GND and should be connected to the ground plane for
improved thermal conductivity. Do not route signals
under these packages.

Chip Information

TRANSISTOR COUNT: 4252

PROCESS: BiCMOS

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and

Buffer for Composite and Y/C Outputs

_______________________________________________________________________________________________________ 5

GSET GAIN (dB)

GND 6

V

CC

9.5

Open 12

Table 1. Gain-Setting Control

COUT

V

CC

GND

1

2

8

7

YOUT

CVOUTGSET

CIN

YIN

3

4

6

5

THIN QFN

TOP VIEW

COUT

V

CC

GND

1

2

8

7

YOUT

CVOUT

GSET

CIN

YIN

3

4

6

5

SO

MAX7443
MAX7444

MAX7443
MAX7444

Pin Configurations

Selector Guide

PART HIGH-FREQUENCY BOOST

MAX7443ETA No

MAX7443ESA No

MAX7444ETA Yes

MAX7444ESA Yes

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs

6 _______________________________________________________________________________________

8L, SOIC EXP. PAD.EPS

C

1

1

21-0111

PACKAGE OUTLINE
8L SOIC, .150" EXPOSED PAD

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

.)

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and

Buffer for Composite and Y/C Outputs

_______________________________________________________________________________________ 7

Package Information (continued)

(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

.)

6, 8, &10L, DFN THIN.EPS

MAX7443/MAX7444

Triple-Channel Video Reconstruction Filter and
Buffer for Composite and Y/C Outputs

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

© 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information (continued)

(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

.)

COMMON DIMENSIONS
SYMBOL MIN. MAX.

A 0.70 0.80
D 2.90 3.10
E 2.90 3.10

A1

0.00 0.05

L 0.20 0.40

PKG. CODE N D2 E2 e JEDEC SPEC b

[(N/2)-1] x e

PACKAGE VARIATIONS

0.25 MIN.k

A2 0.20 REF.

2.00 REF0.25±0.050.50 BSC2.30±0.1010T1033-1

2.40 REF0.20±0.05- - - - 0.40 BSC1.70±0.10 2.30±0.1014T1433-1

1.50±0.10 MO229 / WEED-3

0.40 BSC - - - - 0.20±0.05 2.40 REFT1433-2 14 2.30±0.101.70±0.10

T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF
T833-2 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF
T833-3 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF

2.30±0.10 MO229 / WEED-3 2.00 REF0.25±0.050.50 BSC1.50±0.1010T1033-2