Rainbow Electronics MAX7439 User Manual

General Description

The MAX7438/MAX7439 three-channel standard defini­tion video reconstruction filters include a back-porch
clamp that sets the output blanking level of the video
signal to ground. Each channel of the MAX7438/
MAX7439 combines a lowpass filter with adjustable
high-frequency boost levels and an output buffer capa­ble of driving two standard 150Ω video loads. The
blanking level of the output video signal on each chan­nel is clamped to ground, eliminating the need for large
AC-coupling output capacitors. Direct input coupling
circuitry eliminates the need for AC-coupling input
capacitors. This DC-in/DC-out architecture results in
extremely low line-time distortion. The MAX7438/
MAX7439 are ideal for antialiasing and DAC smoothing
in digital video devices such as STBs, DVDs, PVRs,
and hard disk recorders. The MAX7438/MAX7439 oper­ate from ±5V dual supplies.

The three-channel MAX7438/MAX7439 are ideal for Y,
Pb, Pr, and RGB component video signals, three com­posite video signals, and also Y/C plus CVBS video sig­nals. Each filter channel achieves 60dB of attenuation at
27MHz and a maximally flat passband from DC to 5MHz.

The MAX7438 offers an internal gain of +2V/V, while the
MAX7439 offers a gain of +3V/V.

Applications

Features

♦ Back-Porch of Video Output Signal Clamped to

Ground

♦ Eliminates Input/Output AC-Coupling Capacitors

♦ 0.1% Line-Time Distortion

♦ Stopband: 55dB at 27MHz

♦ Passband: ±0.8dB out to 5MHz

♦ Diff Gain = 0.05%, Diff Phase = 0.05 Degrees

♦ Output Clamped to Ground with Loss of Input

♦ Each Output Drives Two 150Ω Video Loads

♦ Up to 2dB of High-Frequency Boost Control

♦ Ideal for CVBS, Y/C (S-Video), and RGB (Y, P

b,Pr

)

Outputs for NTSC, PAL, and SDTV

♦ Filter Bypass Mode

♦ Small 20-Pin 5mm

✕

5mm Thin QFN Package

MAX7438/MAX7439

Triple-Channel Video Reconstruction Filters with

Back-Porch Clamp to GND

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2857; Rev 0; 4/03

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 paddle

Pin Configuration appears at end of data sheet.

EVALUATION KIT

AVAILABLE

Functional Diagram

Set-Top Boxes/HDR/DVD
Game Consoles
Camcorders

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

PART TEMP RANGE PIN-PACKAGE

MAX7438ETP -40°C to +85°C 20 Thin QFN-EP*

MAX7439ETP -40°C to +85°C 20 Thin QFN-EP*

ENCODER

IN1

DAC1

IN2

DAC2

IN3

DAC3

HFB1
HFB2
HFB3

LOWPASS

FILTER

BACK-PORCH

DETECTOR

LOWPASS

FILTER

MAX7438
MAX7439

LOWPASS

FILTER

HIGH-FREQUENCY
BOOST CONTROL/

BYPASS

V

= -5VV

= +5V

SS

CC

75Ω

GAIN/LEVEL

SHIFT

GAIN/LEVEL

SHIFT

GAIN/LEVEL

SHIFT

GENERATOR

GND

BIAS

EXT

10kΩ

OUT1

OUT2

OUT3

75Ω

75Ω

75Ω

75Ω

75Ω

Z0 = 75Ω

Z0 = 75Ω

75Ω

Z0 = 75Ω

Z0 = 75Ω

75Ω

Z0 = 75Ω

Z0 = 75Ω

75Ω

75Ω

75Ω

75Ω

MAX7438/MAX7439

Triple-Channel Video Reconstruction Filters with
Back-Porch Clamp to GND

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..............................................................-0.3V to +6V

V

SS

to GND...............................................................-6V to +0.3V

OUT_ to GND ........................................................-2.5V to +3.5V

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

SS

- 0.3V) to (VCC+ 0.3V)

Maximum Current into Any Pin .........................................±50mA

Continuous Power Dissipation (T

A

= +70°C)
20-Pin 5mm x 5mm Thin QFN (derate 20.8mW/°C

above +70°C)...........................................................1666.7mW

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%, VSS= -5V ±5%, R

EXT

= 10kΩ ±1%, R

HFB_-1

= 15kΩ ±1%, R

HFB_-2

= 1kΩ ±1%, no boost, R

OUT

= 75Ω,

C

OUT

= 0 to 20pF, TA= T

MIN

to T

MAX

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

)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Passband Response

Stopband Attenuation A

HF Boost Step Size f = 4.2MHz 0.45 dB

HFB_ Voltage Range V

Differential Gain dG

Differential Phase dθ

Total Harmonic Distortion THD

Signal-to-Noise Ratio SNR

Group Delay Deviation ∆t

Group Delay Matching t

Line-Time Distortion H

Field-Time Distortion V

f = 100kHz to 4.2MHz, no HF boost -0.6 +0.6

f = 100kHz to 5MHz, no HF boost -0.8 +0.8

f = 27MHz, relative to 100kHz 40 60 dB

SB

Bypass 0 50

No boost 280 360

HFB_

Boost 1 670 850

Boost 2 1360 1700

Boost 3 2250 2750

Boost 4 3500 V

5-step modulated
staircase

5-step modulated
staircase

f = 100kHz to 5MHz,

= 0.7V

V

IN

P-P

Output signal (2V
f = 100Hz to 5MHz

Deviation from 100kHz to 3.58(4.43)MHz 12 30 ns

G

G(MATCH

DIST

DIST

f = 100kHz 2 ns

18µs, 100 IRE bar 0.1 %

130 lines, 18µs, 100 IRE bar 0.2 %

P-P

MAX7438,

= 1V

V

IN

MAX7439,

= 670mV

V

IN

MAX7438,

= 1V

V

IN

MAX7439,

= 670mV

V

IN

MAX7438,

= 700mV

V

IN

MAX7439,

= 460mV

V

IN

) to P-P noise,

P-P

P-P

P-P

P-P

P-P

P-P

68 75 dB

0.05 0.5

0.05 0.5

0.05 0.5

0.05 0.5

0.2 0.5

0.2 0.5

CC

dB

mV

%

Degrees

%

MAX7438/MAX7439

Triple-Channel Video Reconstruction Filters with

Back-Porch Clamp to GND

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +5V ±5%, VSS= -5V ±5%, R

EXT

= 10kΩ ±1%, R

HFB_-1

= 15kΩ ±1%, R

HFB_-2

= 1kΩ ±1%, no boost, R

OUT

= 75Ω,

C

OUT

= 0 to 20pF, TA= T

MIN

to T

MAX

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

Typical Operating Characteristics

(VCC= +5V, VSS= -5V, R

OUT_

= 150Ω, R

EXT

= 10kΩ, no boost, TA= +25°C, unless otherwise noted.)

-80

0.1 100101

MAX7438

AMPLITUDE vs. FREQUENCY

-50

-70

-10

-30

10

-40

-60

0

-20

MAX7438/9 toc01

FREQUENCY (MHz)

GAIN (dB)

NORMALIZED TO 0dB

-80

0.1 100101

MAX7439

AMPLITUDE vs. FREQUENCY

-50

-70

-10

-30

10

-40

-60

0

-20

MAX7438/9 toc02

FREQUENCY (MHz)

GAIN (dB)

NORMALIZED TO 0dB

2.5

2.0

1.5

1.0

0.5

0

-0.5

-1.0

-1.5

-2.0

-2.5

0.1 1 10

MAX7438

PASSBAND AMPLITUDE vs. FREQUENCY

MAX7438/9 toc03

FREQUENCY (MHz)

GAIN (dB)

NORMALIZED TO 0dB

BOOST 4

BOOST 3

BOOST 2

NO BOOST

BOOST 1

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Clamp Accuracy Output blanking level relative to GND -55 +55 mV

Clamp Settling Time

Low-Frequency Gain Gain at 100kHz

Low-Frequency Gain Matching t

Input Voltage Range THD < 0.5% -0.5 +1.8 V

Output Voltage Range V

Channel-to-Channel Crosstalk X

Output Short-Circuit Current I

Input Leakage Current at IN_ I

Input Leakage Current at HFB_ I

Input Resistance 500 kΩ

Supply Voltage Range

Supply Current

Power-Supply Rejection Ratio PSRR VIN = 100mV

Back porch within the specified clamp
accuracy

MAX7438 5.5 6 6.5

MAX7439 9 9.54 10

Channel-to-channel gain matching,

G

f = 100kHz

OUT

TALK

SC

IN_

HFB_

V

V

I

CC

I

SS

f = 5MHz -0.8 +1.8 V

Channel-to-channel crosstalk, f = 5MHz -60 dB

OUT_ shorted to GND or V

CC

Bypass mode, boost 1 to boost 3 0.2

Boost 4 30

CC

SS

VCC = +5.25V, no load 110 160

VSS = -5.25V, no load 110 160

, f = 0 to 3.5MHz 30 dB

P-P

50 Lines

+5 %

50 mA

±1 ±5 µA

4.75 5.25

-4.75 -5.25

dB

µA

V

mA