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General Description

The MAX7457 4-channel video switch is ideal for anti-

aliasing and DAC-smoothing video applications or wher-

ever 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 sin-

gle +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

OUTA

+6dB

75Ω

*OPTIONAL CAPACITORS

75Ω

OUTB

+6dB

75Ω

OUTC

+6dB

75Ω

OUTD

+6dB

SYNC

DETECTOR

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

LOWPASS

FILTER

2-TO-1

MUX

GND

DISABLE

SELA

0.1µF

INA2

0.1µF

INA1

0.1µF

INB

0.1µF

INC

0.1µF

IND

D/A

AUXILIARY VIDEO SOURCE

(VCR, DVD, ETC.)

ENCODER

CVBS

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.

PART TEMP RANGE PIN-PACKAGE

PKG

CODE

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

*EP = Exposed pad.

Summary of content (8 pages)

PAGE 1
9-3560; Rev 0; 1/05 Video Switch for Dual SCART Connectors 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.
PAGE 2
MAX7457 Video Switch for Dual SCART Connectors ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V INA1, INA2, INB, INC, IND to GND ............-0.3V to (VCC + 0.3V) OUTA, OUTB, OUTC, OUTD to GND .........-0.3V to (VCC + 0.3V) SELA, DISABLE to GND .............................-0.3V to (VCC + 0.3V) Maximum Current into Any Pin Except VCC and GND .....±50mA Continuous Power Dissipation (TA = +70°C) 16-Pin TQFN (derate 20.8mW/°C above +70°C)..........
PAGE 3
Video Switch for Dual SCART Connectors (VCC = +5V ±5%, CL = 0 to 20pF, RL = 75Ω to GND for DC-coupled load, RL = 75Ω to VCC/2 for AC-coupled load, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 5V, TA = +25°C.) PARAMETER Input Leakage Current SYMBOL CONDITIONS MIN TYP IIN Input Dynamic Swing Mux Crosstalk MAX UNITS 10 µA Channel INA_ 1.2 Channels INB, INC, IND 0.9 f = 100kHz to 4.1MHz -60 VP-P dB SUPPLY Supply Voltage Range VCC Supply Current 4.
PAGE 4
Typical Operating Characteristics (continued) (VCC = +5V, TA = +25°C, unless otherwise noted.) 2T RESPONSE (1 IRE = 7.14mV) GROUP DELAY vs. FREQUENCY MAX7457 toc04 90 GROUP DELAY (ns) MODULATED 12.5T RESPONSE (1 IRE = 7.14mV) MAX7457 toc05 100 MAX7457 toc06 IN_ 300mV/div IN_ 300mV/div OUT_ 300mV/div OUT_ 300mV/div 80 70 60 50 40 0.1 10 1 200ns/div 400µs/div DIFFERENTIAL GAIN MULTIBURST RESPONSE MAX7457 toc07 INPUTS BIASED TO +2V NO LOAD 110 MAX7457 toc09 0.3 0.2 0.1 0 -0.1 -0.2 -0.
PAGE 5
Video Switch for Dual SCART Connectors PIN NAME FUNCTION 1 INB Channel INB Video Input. Use channel INB for the red (R) signal. AC-couple INB with a series 0.1µF capacitor. 2 INC Channel INC Video Input. Use channel INC for the green (G) signal. AC-couple INC with a series 0.1µF capacitor. 3 IND Channel IND Video Input. Use channel IND for the blue (B) signal. AC-couple IND with a series 0.1µF capacitor. 4 DISABLE Disable Logic Input. A logic low on DISABLE enables the output buffers.
PAGE 6
Output Buffers Each output buffer has a fixed gain of +6dB and can drive two 150Ω video loads with a 2VP-P signal. The MAX7457 can drive an AC-coupled load or drive a DCcoupled load, eliminating the large coupling capacitors. The output buffers drive DC loads with an output blanking level of less than 1V. Output Clamp Level The video signal processed by channel INA_ (CVBS video signal) must include a sync pulse. This sync pulse provides the required timing to all four channels.
PAGE 7
Video Switch for Dual SCART Connectors QFN THIN.EPS D2 D b CL 0.10 M C A B D2/2 D/2 k L MARKING AAAAA E/2 E2/2 CL (NE-1) X e E DETAIL A PIN # 1 I.D. E2 PIN # 1 I.D. 0.35x45° e/2 e (ND-1) X e DETAIL B e L1 L CL CL L L e e 0.10 C A C 0.08 C A1 A3 PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm -DRAWING NOT TO SCALE- COMMON DIMENSIONS A1 A3 b D E e 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0 0.02 0.05 0 0.02 0.05 0 0.02 0.
PAGE 8
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.) QFN THIN.EPS MAX7457 Video Switch for Dual SCART Connectors D2 D b CL 0.10 M C A B D2/2 D/2 k L MARKING AAAAA E/2 E2/2 CL (NE-1) X e E DETAIL A PIN # 1 I.D. E2 PIN # 1 I.D. 0.35x45° e/2 e (ND-1) X e DETAIL B e L1 L CL CL L L e e 0.10 C A C 0.