Rainbow Electronics MAX7457 User Manual

General Description

The MAX7457 4-channel video switch is ideal for anti­aliasing and DAC-smoothing video applications or wher­ever analog video is reconstructed from a digital data
stream such as cable/satellite/terrestrial set-top boxes
(STBs), DVD players, hard disk recorders (HDRs), and
personal video recorders (PVRs). The MAX7457 filters
and buffers CVBS and RGB video signals, making it
ideal for dual SCART (peritelevision) STBs with an
auxiliary CVBS input. The MAX7457 operates from a sin­gle +5V supply and has a flat passband out to 5MHz
with a stopband attenuation of 43dB at 27MHz, making
it ideal for NTSC, PAL, and standard-definition digital TV
(SDTV) video systems.

The MAX7457 output buffers have a fixed gain of +6dB
and are capable of driving two standard 150Ω video
loads. The channel for CVBS video has high-frequency
boost circuitry that enhances picture sharpness with up
to +1.2dB of gain boost without degradation in the
stopband. The video output drivers can be disabled by
an external control input.

The MAX7457 is available in a 16-pin, 5mm x 5mm x

0.8mm TQFN package, and is specified over the
extended (-40°C to +85°C) temperature range.

Applications

STBs/HDRs DVD Players

Game Consoles Digital VCRs

Desktop Video Editors

Features

♦ 4-Channel Video Filter/Buffer for RGB and CVBS

Signals with Auxiliary Input

♦ Allows Auxiliary Input for CVBS Video Loop-

Through Applications

♦ 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 Operation

♦ Available in 5mm x 5mm x 0.8mm, 16-Pin TQFN

MAX7457

Video Switch for Dual SCART Connectors

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

MAX7457

75Ω

75Ω

*

*

75Ω

75Ω

OUTA

+6dB

75Ω

75Ω

*

*OPTIONAL CAPACITORS

*

75Ω

75Ω

OUTB

+6dB

75Ω

75Ω

*

*

75Ω

75Ω

OUTC

+6dB

75Ω

75Ω

*

*

75Ω

75Ω

OUTD

+6dB

SYNC

DETECTOR

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

2-TO-1

MUX

GND

DISABLE

SELA

V

CC

0.1µF
INA2

0.1µF
INA1

0.1µF

INB

0.1µF

INC

0.1µF

IND

D/A

D/A

D/A

D/A

AUXILIARY VIDEO SOURCE

(VCR, DVD, ETC.)

ENCODER

CVBS

R

B

G

Typical Operating Circuit

19-3560; Rev 0; 1/05

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.

Pin Configuration appears at end of data sheet.

*EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX7457ETE -40°C to +85°C 16 TQFN-EP* T1655-2

PKG

CODE

MAX7457

Video Switch for Dual SCART Connectors

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

CC

= +5V ±5%, CL= 0 to 20pF, RL= 75Ω to GND for DC-coupled load, RL= 75Ω to VCC/2 for AC-coupled load, TA= 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..............................................................-0.3V to +6V

INA1, INA2, INB, INC, IND to GND ............-0.3V to (V

CC

+ 0.3V)

OUTA, OUTB, OUTC, OUTD to GND.........-0.3V to (V

CC

+ 0.3V)

SELA, DISABLE 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)
16-Pin TQFN (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

)

(

)

Passband Flatness

Stopband Attenuation A

Differential Gain dG 5-step modulated staircase 0.15 0.5 %

Differential Phase dθ 5-step modulated staircase 0.15 0.5 Degrees

Signal-to-Noise Ratio SNR

Group Delay Deviation ∆t

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

Disabled Output Impedance Z

Output Short-Circuit Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

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

f ≥ 27MHz 40 43 dB

SB

Peak signal (2V
to 50MHz

Deviation from

g

100kHz to 4.1MHz

DIST

DIST

CLAMP

18µs, 100 IRE bar 0.3 %

130 lines, 18µs, 100 IRE bar 0.5 %

To ±1% 300 Lines

Channel INA_ 0.6 0.9 1.1

Channel INB, INC, IND 1.1 1.5 1.8

f = 100kHz, relative to gain of +6dB -3 +3 %

V

V(MATCH

t

g

MATCH

TALK

DISABLE

SC

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

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

f = 100kHz to 3.58MHz -60 dB

At 5MHz 2 kΩ

OUT_ shorted to GND or V

Channel INA_ +0.9 +1.2 +1.5

Channels INB,
INC, IND

) to RMS noise, f = 100Hz

P-P

-0.75 +0.15 +0.75

80 dB

Channel INA_ 17 30

Channels INB,
INC, IND

11 20

4%

2ns

CC

70 mA

dB

ns

V

MAX7457

Video Switch for Dual SCART Connectors

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V

CC

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

MAX7457 toc01

FREQUENCY (MHz)

AMPLITUDE (dB)

10

-60

-40

-20

0

-80
1100

CHANNEL INA_

PASSBAND AMPLITUDE vs. FREQUENCY

MAX7457 toc02

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

CHANNEL INA_

CHANNELS INB/INC/IND

PHASE RESPONSE vs. FREQUENCY

MAX7457 toc03

FREQUENCY (MHz)

PHASE (DEGREES)

1

-150

-100

-50

0

50

100

150

200

-200

0.1 10

Input Leakage Current I

Input Dynamic Swing

Mux Crosstalk f = 100kHz to 4.1MHz -60 dB

SUPPLY

Supply Voltage Range V

Supply Current I

Power-Supply Rejection Ratio PSRR V

LOGIC INTERFACE

Logic Input High Voltage V

Logic Input Low Voltage V

Logic Input Current VIL = 0 (sink), VIH = V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IN

10 µA

Channel INA_ 1.2

Channels INB, INC, IND 0.9

CC

CC

No load 100 140 mA

= 100mV

IN

IH

IL

, f = 0 to 3.5MHz 40 dB

P-P

(source) ±10 µA

CC

4.75 5.25 V

2.0 V

0.8 V

V

P-P