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General Description

The MAX4550/MAX4570 serial-interface, programma-

ble, dual 4x2 audio/video crosspoint switches are ideal

for multimedia applications. Each device contains two

identical crosspoint switch arrays, each with four inputs

and two outputs. To improve off-isolation, use the addi-

tional crosspoint inputs SA and SB as shunts. Each out-

put is selectively programmable for clickless or regular

mode operation. A set of internal resistive voltage-

dividers supplies DC bias for each output when using

AC-coupled inputs. Additionally, four auxiliary outputs

control additional circuitry via the MAX4550/MAX4570’s

2-wire or 3-wire interface.

The MAX4550/MAX4570 feature 80

Ω on-resistance, 10Ω

on-resistance matching between channels, 5

Ω on-

resistance flatness, and 0.014% total harmonic distor-

tion. Additionally, they feature off-isolation of at least

-110dB in the audio frequency range and -78dB at

4MHz, with -95dB crosstalk in the audio frequency

range and -54dB at 4MHz. The MAX4550 uses a 2-wire

uses a 3-wire SPI™/QSPI™ or MICROWIRE™-compati-

ble serial interface. These parts are available in 28-pin

SSOP and wide SO packages and are tested over

either the commercial (0°C to +70°C) or extended

(-40°C to +85°C) operating temperature range.

Applications

Set-Top Boxes

PC Multimedia Boards

High-End Audio Systems

Video Conferencing Systems

Features

o Selectable Soft Switching Mode for Clickless

Audio Operation

o 43

Ω Typical On-Resistance (±5V Supplies)

o 5

Ω Typical On-Resistance Matching Between

Channels

o 4

Ω Typical On-Resistance Flatness

o 0.014% Total Harmonic Distortion with 1k

Ω Load

o -110dB Off-Isolation at 20kHz

-78dB Off-Isolation at 4MHz

o -95dB Crosstalk at 20kHz

-54dB Crosstalk at 4MHz

o Serial Interface

3-Wire, SPI/QSPI/MICROWIRE-Compatible

(MAX4570)

o Four Auxiliary Outputs that Extend µP Ports

o Single-Supply Operation: +2.7V to +5.5V

Dual-Supply Operation: ±2.7V to ±5.5V

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

________________________________________________________________

Maxim Integrated Products

1

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

SA

NO2B

NO2A

V-

V+

NO1B

SDA (DIN)

NO1A

GND

COM1A

Q3

COM1B

Q2

A1 (DOUT)

SCL (SCLK)

A0 (CS)

Q1

COM2B

( ) ARE FOR MAX4570.

Q0

COM2A

V+

NO4B

NO4A

BIASL

BIASH

NO3B

NO3A

SB

SO/SSOP

TOP VIEW

MAX4550

MAX4570

19-1397; Rev 0; 10/98

PART

MAX4550CAI

MAX4550CWI

MAX4550EAI

-40°C to +85°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

28 SSOP

28 Wide SO

28 SSOP

EVALUATION

KIT

AVAILABLE

Functional Diagram appears at end of data sheet.

Pin Configuration

Ordering Information

MAX4550EWI

-40°C to +85°C

28 Wide SO

MAX4570CAI

MAX4570CWI

MAX4570EAI

-40°C to +85°C

0°C to +70°C

0°C to +70°C

28 SSOP

28 Wide SO

28 SSOP

MAX4570EWI

-40°C to +85°C

28 Wide SO

SPI/QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.