Rainbow-electronics MAX9671 Manual de usuario descargar pdf

General Description

The MAX9670/MAX9671 dual SCART matrices route

audio and video signals between a set-top box

decoder chip and two external SCART connectors

under I

C control. Operating from a 3.3V supply and a

12V supply, the MAX9670/MAX9671 consume 70mW

during quiescent operation and 471mW during average

operation when driving typical signals into typical

loads. Video input detection, video load detection, and

a 2.5mW standby mode facilitate the design of intelli-

gent, low-power set-top boxes.

The MAX9670/MAX9671 audio section contains a

buffered crosspoint to route audio inputs to audio out-

puts and programmable volume control from -62dB to

0dB in 2dB steps. The DirectDrive

output amplifiers

create a 2V

RMS

full-scale audio signal biased around

ground, eliminating the need for bulky output capaci-

tors and reducing click-and-pop noise. The zero-cross

detection circuitry also further reduces clicks and pops

by enabling audio sources to switch only during a zero-

crossing. The MAX9671 offers TV left and right audio

inputs.

The MAX9670/MAX9671 video section contains a

buffered crosspoint to route video inputs to video out-

puts. The standard-definition video signals from the set-

top box decoder chip are lowpass filtered to remove

out-of-band artifacts.

The MAX9670/MAX9671 also support slow-switching

and fast-switching signals. An interrupt signal from the

MAX9670/MAX9671 informs the microcontroller when

the system status has changed.

Applications

Set-Top Boxes

TVs

DVD Players

Features

o 70mW Quiescent Power Consumption

o 2.5mW Standby Mode Consumption

o Programmable Audio Gain Control of -62dB to

0dB (TV Audio Outputs)

o Clickless, Popless, DirectDrive Audio

o Video Input and Video Load Detection

o Video Reconstruction Filter with 10MHz Passband

and 52dB Attenuation at 27MHz

o 3.3V and 12V Supply Voltages

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

________________________________________________________________

Maxim Integrated Products

19-4653; Rev 0; 7/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

Ordering Information

PART TEMP RANGE

PIN-

PACKAGE

TV R+L

AUDIO

INPUTS

MAX9670CTL+ 0°C to +70°C 40 TQFN-EP* No

MAX9671CTH+ 0°C to +70°C 44 TQFN-EP* Yes

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

DirectDrive is a registered trademark of Maxim Integrated

Products, Inc.

Typical Application Circuit appears at end of data sheet.

C INTERFACE

REGISTERS AND

ACTIVITY

MONITOR

VIDEO FILTERS AND

CROSSPOINT

AUDIO CROSSPOINT

WITH DIRECTDRIVE

OUTPUTS, VOLUME

CONTROL

SLOW SWITCHING

FAST SWITCHING

CHARGE PUMP

AUD

VID

12V 3.3V3.3V

EP GNDVID

µC

VIDEO

ENCODER

STEREO

AUDIO

DAC

INTERRUPT

OUTPUT

RGB, Y/C, CVBS

SINGLE-ENDED R/L

STEREO AUDIO

RGB, Y/C, CVBS

CVBS

L/R AUDIO

(MAX9671 ONLY)

SLOW SWITCHING

Y/C, CVBS

RGB, Y/C, CVBS

L/R AUDIO

SLOW SWITCHING

STB CHIP

SCART

VCR

SCART

FAST SWITCHING

L/R AUDIO

(MAX9670 ONLY)

MAX9670/MAX9671

System Block Diagram

1 2 3 4 5 6 ... 41 42

MAX9670/MAX9671 1

Indice de contenidos

Pagina 1 - MAX9670/MAX9671

General DescriptionThe MAX9670/MAX9671 dual SCART matrices routeaudio and video signals between a set-top boxdecoder chip and two external SCART conne

Pagina 2

MAX9670/MAX9671Low-Power Audio/Video Switch with AudioVolume Control for Dual SCART Connectors10 _____________________________________________________

Pagina 3