Maxim MAX4570EWI, MAX4570EAI, MAX4550CAI, MAX4550EWI, MAX4550EAI Datasheet

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General Description

The MAX4550/MAX4570 serial-interface, programma­ble, 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 addi­tional crosspoint inputs SA and SB as shunts. Each out­put is selectively programmable for clickless or regular
mode operation. A set of internal resistive voltage­dividers 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 80Ω on-resistance, 10Ω
on-resistance matching between channels, 5Ω on­resistance flatness, and 0.014% total harmonic distor­tion. 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
I2C-compatible serial interface, while the MAX4570
uses a 3-wire SPI™/QSPI™ or MICROWIRE™-compati­ble 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

♦ Selectable Soft Switching Mode for Clickless

Audio Operation

♦ 43Ω Typical On-Resistance (±5V Supplies)
♦ 5Ω Typical On-Resistance Matching Between

Channels

♦ 4Ω Typical On-Resistance Flatness
♦ 0.014% Total Harmonic Distortion with 1kΩ Load
♦ -110dB Off-Isolation at 20kHz

-78dB Off-Isolation at 4MHz

♦ -95dB Crosstalk at 20kHz

-54dB Crosstalk at 4MHz

♦ Serial Interface

2-Wire, Fast-Mode, I

2

C-Compatible (MAX4550)
3-Wire, SPI/QSPI/MICROWIRE-Compatible
(MAX4570)

♦ Four Auxiliary Outputs that Extend µP Ports
♦ Single-Supply Operation: +2.7V to +5.5V

Dual-Supply Operation: ±2.7V to ±5.5V

MAX4550/MAX4570

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
V­V+
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

I2C is a trademark of Philips Corp.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.

Channel-to-Channel Crosstalk V

CTA(A)

ICOM_ _ = 1mA

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ANALOG ELECTRICAL CHARACTERISTICS—Dual Supplies

(V+ = +5V ±5%, V- = -5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

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.

Note 1: Signals on NO_ _, S_, or COM_ _ exceeding V+ or V- are clamped by internal diodes. Limit forward-diode current to maxi-

mum current rating.

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

V+ to V-................................................................-0.3V to +13.2V

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

NO_ _ , S_, BIAS_, COM_ _, Q_, A1, DOUT to GND

(Note 1)...............................................(V- - 0.3V) to (V+ + 0.3V)

CS, SCLK, DIN, SCL, SDA, A0 to GND....................-0.3V to +6V

Continuous Current into Any Terminal..............................±10mA

Peak Current, NO_ _ , S_ , COM_ _

(pulsed at 1ms, 10% duty cycle max) ..........................±40mA

Continuous Power Dissipation (T

A

= +70°C)

28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW

28-Pin Wide SO (derate 12.5mW/°C above +70°C) ...1000mW

Operating Temperature Ranges

MAX4550C_I/MAX4570C_I ...............................-0°C to +70°C

MAX4550E_I/MAX4570E_I ..............................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

I

COM_ _

= 4mA,

V

NO_ _

or VS_= ±3.0V,

V+ = 4.75V, V- = -4.75V

CONDITIONS

Ω

43 80

R

ON

On-Resistance

VV- V+

V

NO_ _

,

V

COM_ _

,

V

S_

Analog Signal Range (Note 3)

UNITSMIN TYP MAXSYMBOLPARAMETER

-110

TA= +25°C
TA= T

MIN

to T

MAX

100

I

COM_ _

= 4mA,

V

NO_ _

or VS_= ±3.0V,

V+ = 4.75V, V- = -4.75V

Ω

5 10

∆R

ON

COM_ _ to NO_ _ or S_
On-Resistance Match Between
Channels (Note 4)

TA= +25°C
TA= T

MIN

to T

MAX

10

I

COM_ _

= 4mA;

V

NO_ _

or VS_= ±3.0V, 0;

V+ = 4.75V; V- = -4.75V

Ω

4 5

∆R

FLAT(ON)

COM_ _ to NO_ _ or S_
On-Resistance Flatness
(Note 5)

TA= +25°C
TA= T

MIN

to T

MAX

8

V

NO_ _

or VS_= ±4.5V,

V

COM_

=

–

+

4.5V,

V+ = 5.25V, V- = -5.25V

nA

-1 0.01 1

NO

_(OFF)

NO_ _ or S_ Off-Leakage
Current (Note 6)

TA= +25°C
TA= T

MIN

to T

MAX

-10 10

V

NO_ _

or VS_= ±4.5V,

V

COM_

=

–

+

4.5V,

V+ = 5.25V, V- = -5.25V

nA

-5 0.01 5

I

COM

_(OFF)

COM_ _ Off-Leakage Current
(Note 6)

TA= +25°C
TA= T

MIN

to T

MAX

-10 10

V

NO_ _

or VS_= floating,

V

COM_

= ±4.5V,

V+ = 5.25V, V- = -5.25V

nA

-5 0.01 5

I

COM

_(ON)

COM_ _ On-Leakage Current
(Note 6)

TA= +25°C
TA= T

MIN

to T

MAX

-20 20

V

NO_ _

or VS_= 1V

RMS

, fIN= 20kHz,

RL= 10kΩ, three channels driven at 20kHz

dB-95V

CTA(A)

Channel-to-Channel Crosstalk

VNO= 1V

RMS

, fIN= 20kHz,

RL= 10kΩ, S = GND

dB

-80

V

ISO(A)

Off-Isolation (Note 7)

fIN= 1kHz, RL= 1kΩ, V

NO_

or VS_= 1V

RMS

,

V

NO_

or VS_= 0

%0.014THD+N

Total Harmonic Distortion plus
Noise

Shunt switch on
Shunt switch off

ANALOG SWITCHES

AUDIO PERFORMANCE

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

_______________________________________________________________________________________ 3

ANALOG ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)

(V+ = +5V ±5%, V- = -5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

fIN= 1MHz,

CONDITIONS

pF11C

OFF(NO)

Off-Capacitance

-78

UNITSMIN TYP MAXSYMBOLPARAMETER

Shunt switch on
Shunt switch off

V

NO_ _

or VS_= 1

VRMS

,
fIN= 4MHz, RL= 1kΩ,
S_ = GND

dB

-63

V

ISO(V)

Off-Isolation

RS= 75Ω, RL= 1kΩ MHz14BW0.1dB Bandwidth

V

NO_ _

or V

S_

= 1.5V, RL= 300Ω

V

NO_ _

or V

S_

= 1.5V, RL= 5kΩ

ns200 500t

OFFSD

Turn-Off Time (Note 9)

ns400 900t

ONSD

Turn-On Time (Note 9)

V

NO_ _

or V

S_

= 1.5V ns10 100t

BBM

Break-Before-Make Time

V

NO_ _

or V

S_

= 1.5V, RL= 300Ω

V

NO_ _

or V

S_

= 1.5V, RL= 5kΩ

ms11t

OFFSE

Turn-Off Time

ms36t

ONSE

Turn-On Time

BIASH to BIASL kΩ13 20 27R

BIAS

Bias Network Resistance

Reset condition, V+ = 2.7V to 5.25V µA7 20I+V+ Supply Current (Note 10)

V+

Reset condition, V- = -5.25V to 0 µA-20I-V- Supply Current

V

NO_ _

or VS_= 1

VRMS

, fIN= 4MHz,
R

L

= 10Ω, three channels driven at 4MHz

dB-54V

CT(V)

Channel-to-Channel Crosstalk

V

2.7 5.25

V-

Supply Voltage Range

-5.25 0

ANALOG ELECTRICAL CHARACTERISTICS—Single +5V Supply

(V+ = +5V ±5%, V- = 0, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

I

COM_ _

= 4mA,

V

NO_ _

or VS_= 3.0V,

V+ = 4.75V

I

COM_ _

= 4mA,

V

NO_ _

or VS_= 3.0V,

V+ = 4.75V

Ω

5 10

∆R

ON

On-Resistance Match Between
Channels (Note 4)

CONDITIONS

V

NO

or VS_= 4.5V, 1V;

V

COM_ _

= 1V, 4.5V;

V+ = 5.25V

nA

-1 0.01 1

I

NO_ _(OFF)

NO_ _ or S_ Off-Leakage
Current (Notes 6, 11)

TA= +25°C
TA= T

MIN

to T

MAX

-10 10

I

COM_ _

= 4mA;

V

NO_ _

or VS_= 1V, 2V,

3V; V+ = 4.75V

Ω

4 10

Ω

60 100

R

ON

On-Resistance

V0 V+

V

NO_ _

,

V

COM_ _

,

V

S_

Analog Signal Range (Note 3)

R

FLAT

On-Resistance Flatness
(Note 5)

TA= +25°C
TA= T

MIN

to T

MAX

15

UNITSMIN TYP MAXSYMBOLPARAMETER

TA= +25°C

TA= +25°C
TA= T

MIN

to T

MAX

130

TA= T

MIN

to T

MAX

10

VIDEO PERFORMANCE

DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Note 8)

DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Note 8, Figure 5)

BIAS NETWORKS

POWER SUPPLIES

ANALOG SWITCHES

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

4 _______________________________________________________________________________________

ANALOG ELECTRICAL CHARACTERISTICS—Single +5V Supply (continued)

(V+ = +5V ±5%, V- = 0, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

V

NO_ _

or VS_= floating;

V

COM_ _

= 1V, 4.5V;

V+ = 5.25V

nA

Shunt switch on

-5 0.01 5

I

COM_ _(ON)

COM_ _ On-Leakage Current
(Notes 6, 11)

CONDITIONS

Shunt switch off

-105

TA= +25°C
TA= T

MIN

to T

MAX

-20 20

V

NO_ _

or VS_= 1V

RMS

, fIN=

20kHz, RL= 10kΩ, S = GND
V

NO_ _

or VS_= 1V

RMS

, fIN= 20kHz,

RL= 10kΩ, three channels driven at 20kHz

dB

-80

V

ISO(A)

Off-Isolation (Note 7)

dB-97V

TC(A)

V

NO_ _

or VS_= 4.5V, 1V;

V

COM_ _

= 1V, 4.5V;

V+ = 5.25V

nA

-5 0.01 5

I

COM_ _(OFF)

COM_ _ Off-Leakage Current
(Notes 6, 11)

TA= +25°C
TA= T

MIN

to T

MAX

-10 10

Channel-to-Channel Crosstalk

fIN= 1kHz, RL= 10kΩ, V

NO_ _

or VS_= 1V

RMS

,

V

NO_ _

or VS_= 2.5V

%0.014THD+N

Total Harmonic Distortion plus
Noise

UNITSMIN TYP MAXSYMBOLPARAMETER

-74

V

NO_ _

or VS_= 1V

RMS

, fIN=

4MHz, RL= 1kΩ, S = GND

dB

-61

V

ISO(V)

Off-Isolation (Note 7)

R

SOURCE

= 75Ω, RL= 1kΩ MHz13BW0.1dB Bandwidth

fIN= 1MHz pF11C

OFF(NO)

Off-Capacitance

V

NO_ _

or V

S_

= 1.5V, RL= 5kΩ ns400 900t

ONSD

Turn-On Time (Note 9)

V

NO_ _

or V

S_

= 1.5V, RL= 300Ω ns160 500t

OFFSD

Turn-Off Time (Note 9)

V

NO_ _

or V

S_

= 1.5V ns10 100t

BBM

Break-Before-Make Time

V

NO_ _

or V

S_

= 1.5V, RL= 5kΩ ms43t

ONSE

Turn-On Time

V

NO_ _

or V

S_

= 1.5V, RL= 300Ω ms14t

OFFSE

Turn-Off Time

BIASH to BIASL kΩ13 20 27R

BIAS

Bias Network Resistance

V

NO_ _

or VS_= 1V

RMS

, fIN= 4MHz,

RL= 10kΩ, three channels driven at 4MHz

dB-52V

TC(V)

Channel-to-Channel Crosstalk

ANALOG ELECTRICAL CHARACTERISTICS—Single +3V Supply

(V+ = +3V ±10%, V- = 0, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

I

COM_ _

= 4mA,

V

NO_ _

or VS_= 1V,

V+ = 2.7V

CONDITIONS

Ω

106 180

R

ON

On-Resistance

V0 V+

V

NO_ _

,

V

COM_ _

,

V

S_

Analog Signal Range (Note 3)

UNITSMIN TYP MAXSYMBOLPARAMETER

TA= +25°C
TA= T

MIN

to T

MAX

220

ANALOG SWITCHES

Shunt switch on
Shunt switch off

AUDIO PERFORMANCE

VIDEO PERFORMANCE

DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Note 8)

DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Note 8, Figure 5)

BIAS NETWORKS

I

SINK

= 6mA

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

_______________________________________________________________________________________ 5

INTERFACE I/O CHARACTERISTICS

(V+ = +2.7V to +5.5V, V- = 0 to -5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

I

SOURCE

= 1mA to GND, V+ = 4.75V

CONDITIONS

4.45 4.65

UNITSMIN TYP MAXSYMBOLPARAMETER

V

2.3 2.5

V

OH

Output High Voltage

I

SOURCE

= 0.5mA to GND, V+ = 2.7V

V

0.5 1.0

V

OL

Output Low Voltage

I

SINK

= 12mA, V+ = 4.75V

0.5 1.0I

SINK

= 6mA, V+ = 2.7V

V+ > 3.6V 3.0

V+ > 3.6V 0.8

V+ < 3.6V

V

2.0

V

IH

Input High Voltage

V0.2

V+ < 3.6V

V

HYST

Input Hysteresis

V

NO_ _

= 0 or 5V µA-1 0.01 1I

LEAK

Input Leakage Current (Note 7)

0.4

I

SOURCE

= 0.5mA VV+ - 0.5 V+ - 0.1

I

SINK

= 6mA

V

OH

DOUT Output High Voltage

V

0.8

V

OL

Output Low Voltage

V

0.6

V

IL

Input Low Voltage

kHzDC 400f

SCL

SCL Clock Frequency

µs0.6t

SU:STO

STOP Condition Setup Time

ns100t

SU:DAT

Data Setup Time

µs0 0.9t

HD:DAT

Data Hold Time

µs1.3t

BUF

Bus Free Time between Stop
and Start Condition

µs1.3t

LOW

Clock Low Period

µs0.6t

HIGH

Clock High Period

MHzDC 2.1f

OP

Operating Frequency

ns0f

DH

DIN to SCLK Hold

ns100f

DS

DIN to SCLK Setup

ns20 200f

DO

SCLK Fall to Output Data Valid C

LOAD

= 50pF

ns0f

CSH

CS to SCLK Rise Hold

ns100f

CSS

CS to SCLK Rise Setup

ns

20 + 300

0.1Cb

t

R

SCL/SDA Rise Time
(Note 12)

ns

20 + 300

0.1Cb

t

F

SCL/SDA Fall Time
(Note 12)

pF5C

NO

Input Capacitance

V+ = 4.75V
V+ = 2.7V

SPI TIMING (V+ = +4.75V to +5.25V, Figures 3, 4)

I2C TIMING (V+ = +4.75V to +5.25V, Figures 1, 2)

DIGITAL OUTPUTS (DOUT, SDA)

DIGITAL INPUTS (SCK, DIN, CS, SCL, SDA)

AUXILIARY OUTPUTS

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

6 _______________________________________________________________________________________

INTERFACE I/O CHARACTERISTICS (continued)

(V+ = +2.7V to +5.5V, V- = 0 to -5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

ns200t

CL

SCLK Pulse Width High

ns200t

CH

SCLK Pulse Width Low

µs2.0t

R

Rise Time (SCLK, DIN, CS)

µs2.0t

F

Fall Time (SCLK, DIN, CS)

Note 2: The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
Note 3: Guaranteed by design. Not subject to production testing.
Note 4: ∆R

ON

= R

ON(MAX)

- R

ON(MIN)

.

Note 5: On-resistance flatness is defined as the difference between the maximum and minimum on-resistance values, as measured

over the specified analog signal range.

Note 6: Leakage parameters are 100% tested at maximum rated temperature, and guaranteed by correlation at T

A

= +25°C.

Note 7: Off-isolation = 20

· log (V

COM_ __

/ V

NO_ _

), V

COM_ _

= output, V

NO_ _

= input to off switch.

Note 8: All timing is measured from the clock’s falling edge preceding the ACK signal for 2-wire, and from CS’s rising edge for

3-wire. Turn-Off Time is defined as the output of the switch for 0.5V change, tested with a 300Ω load to ground. Turn-On
Time is measured with a 5kΩ load resistor to GND. All timing is shown with respect to 20% of V+ and 70% of V+, unless
otherwise noted.

Note 9: Typical values are for MAX4570 only.
Note 10: Supply current can be as high as 2mA per switch during switch transitions in the clickless mode, corresponding to 40mA

total supply transient current requirement.

Note 11: Leakage testing for single-supply operation is guaranteed by testing with dual supplies.
Note 12: Cb = capacitance of one bus line in pF. Tested with Cb = 400pF.

40

44
42

48
46

52
50

54

58
56

60

-5 -3 -2 -1-4 0 1 2 43 5

ON-RESISTANCE vs. V

COM

(DUAL SUPPLIES)

AMX4550/4570-01

V

COM

(V)

R

ON

(Ω)

V± = ±2.7V

V± = ±3.3V

V± = ±4.75V

30

35

40

45

50

55

60

-5 -3 -2 -1-4 0 1 2 43 5

ON-RESISTANCE vs. V

COM

AND TEMPERATURE (DUAL SUPPLIES)

AMX4550/4570-02

V

COM

(V)

R

ON

(Ω)

V± = ±5V

TA = +85°C

TA = +70°C

TA = +25°C

TA = -40°C

50

60

70

80

90

100

110

120

130

0 1 2 3 4 5

ON-RESISTANCE vs. V

COM

(SINGLE SUPPLY)

AMX4550/4570-03

V

COM

(V)

R

ON

(Ω)

V+ = +2.7V

V+ = +3.3V

V+ = +5V

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

_______________________________________________________________________________________

7

40

45

50

55

60

65

70

75

0 1 2 3 4 5

ON-RESISTANCE vs. V

COM

AND

TEMPERATURE (SINGLE SUPPLY)

AMX4550/4570-04

V

COM

(V)

R

ON

(Ω)

TA = +70°C

TA = +85°C

TA = +25°C

TA = -40°C

V+ = +5V
V- = 0

30

40
35

50
45

65
60
55

70

-40 0-20 20 40 60 80

ON-RESISTANCE vs. TEMPERATURE

AMX4550/4570-05

TEMPERATURE (°C)

R

ON

(Ω)

V+ = +5V
V- = 0

V± = ±5V

0.1

1

10

1000

100

10,000

-40 0-20 20 40 60 80

LEAKAGE CURRENT vs. TEMPERATURE

AMX4550/4570-06

TEMPERATURE (°C)

LEAKAGE CURRENT (pA)

V± = ±5V

COM_ON

NO_OFF

COM_OFF

1

2

5
4

3

9
8
7
6

10

-40 -20 200 40 60 80

SUPPLY CURRENT vs. TEMPERATURE

(DUAL SUPPLIES)

AMX4550/4570-07

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

I+

I-

V+ = ±5V

200

400
300

600
500

800
700

900

1100
1000

1200

2.7 3.5 3.93.1 4.3 4.7 5.1 5.5

TURN-ON/TURN-OFF TIMES vs.

SUPPLY VOLTAGE (SINGLE SUPPLY)

AMX4550/4570-10

V

SUPPLY

(V)

TIME (ns)

t

ON

t

OFF

1

2

5
4

3

9
8
7
6

10

SUPPLY CURRENT vs. TEMPERATURE

(SINGLE SUPPLY)

AMX4550/4570-08

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

-40 -20 200 40 60 80

V+ = +5V

V+ = +2.7V

V- = 0

0

2

8
6

4

16
14
12
10

18

-4 -1-2-3 0 1 2 3 4-5 5

CHARGE INJECTION vs. V

COM

AMX4550/4570-09

V

COM

(V)

Q (pC)

V± = ±5V

V+ = +5V
V- = 0

200

400
300

500

700
600

800

900

1000

2.7 3.5 3.93.1 4.3 4.7 5.1 5.5

TURN-ON/TURN-OFF TIMES vs.

SUPPLY VOLTAGE (DUAL SUPPLIES)

AMX4550/4570-11

V

SUPPLY

(V)

TIME (ns)

t

ON

t

OFF

10

-90

0.5 1 10 100

OFF-ISOLATION AND CROSSTALK

vs. FREQUENCY

-60

-70

-80

0

-10

-20

-30

-40

-50

AMX4550/4570-12

FREQUENCY (MHz)

CROSSTALK (dB)

V± = ±5V

OFF-ISOLATION

CROSSTALK

-30

-130

-100

-110

-120

-40

-50

-60

-70

-80

-90

ISOLATION (dB)

Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

2

-8

0.5 1 10 100 500

FREQUENCY RESPONSE

-5

-6

-7

1
0

-1

-2

-3

-4

AMX4550/4570-13

FREQUENCY (MHz)

LOSS (1dB/div)

V± = ±5V

0.20

-0.30

0.5 1 2 5 10 20

FREQUENCY RESPONSE

-0.15

-0.20

-0.25

0.15

0.10

0.05
0

-0.05

-0.10

AMX4550/4570-14

FREQUENCY (MHz)

LOSS (dB)

V± = ±5V

0.1

0.001
1 10 100 1000 10,000 100,000

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

0.01

AMX4550/4570-15

FREQUENCY (Hz)

THD+NOISE (%)

R

LOAD

= 10kΩ

V± = ±5V

0

500µs/div

COM RISE TIME (SOFT MODE)

200mV/

div

AMX4550/4570-16

V± = ±5V

0

25ns/div

COM TURN-OFF TIME (HARD MODE)

0

COM

0.5V/div

CS

1V/div

AMX4550/4570-19

V± = ±5V

0

500µs/div

COM FALL TIME (SOFT MODE)

200mV/

div

AMX4550/4570-17

V± = ±5V

0

50ns/div

COM TURN-ON TIME (HARD MODE)

0

COM

0.5V/div

CS

1V/div

AMX4550/4570-18

V± = ±5V

0

5ms/div

COM TURN-ON TIME (SOFT MODE)

0

COM

0.5V/div

CS

1V/div

AMX4550/4570-20

V± = ±5V

0

5ms/div

COM TURN-OFF TIME (SOFT MODE)

0

COM

0.5V/div

CS

1V/div

AMX4550/4570-21

V± = ±5V

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

_______________________________________________________________________________________ 9

Pin Description

Shunt Input to Crosspoint B. Use for shunt capacitor or AC ground connection to
improve off-isolation, or as an additional input to switch matrix B.

11

Input 3 to Crosspoint A22
Input 3 to Crosspoint B33

NO3A
NO3B

SB

Low Side of Bias Network. Use to give the outputs a DC bias when inputs are
AC-coupled (refer to the

Using the Internal Bias Resistors

section).

55

Input 4 to Crosspoint A66

BIASL
NO4A

BIASH

High Side of Bias Network. Use to give the outputs a DC bias when inputs are
AC-coupled (refer to the

Using the Internal Bias Resistors

section).

44

Positive Supply Voltage. Supply range is +2.7V to +5.25V. Connect pin 8 to pin 24 exter­nally.

8, 248, 24

Output 2 of Crosspoint A99

V+

COM2A

NO4B

Output 2 of Crosspoint B1111
Auxiliary Output 11212

COM2B

Q1

Q0 Auxiliary Output 01010

Input 4 to Crosspoint B77

Chip Select of 3-Wire Interface. Logic low on CS enables serial data to be clocked in to
device. Programming commands are executed on CS’s rising edge.

13—

2-Wire Serial-Interface Clock Input —14

CS

SCL

A0

2-Wire Serial-Interface Data Input. Data is clocked in on SCL’s rising edge.—15
3-Wire Serial-Interface Data Input. Data is clocked in on SCLK’s rising edge.15—

SDA

DIN

SCLK 3-Wire Serial-Interface Clock Input14—

Data Output of 3-Wire Interface. Input data is clocked out and SCLK’s falling edge
delayed by 16 clock cycles. DOUT remains active when CS is high.

16—

Auxiliary Output 21717

DOUT

Q2

A1

Auxiliary Output 3

LSB+1 of 2-Wire Serial-Interface Address Field—13

1919

Output 1 of Crosspoint A2020

Q3

COM1A

COM1B Output 1 of Crosspoint A1818

LSB+2 of 2-Wire Serial-Interface Address Field—16

Ground2121 GND
Input 1 to Crosspoint A2222 NO1A
Input 1 to Crosspoint B2323 NO1B
Negative Supply Voltage. Supply range is from -5.25V to 0.2525 V­Input 2 to Crosspoint A2626 NO2A
Input 2 to Crosspoint B2727 NO2B
Shunt Input to Crosspoint A. Use for shunt capacitor or AC ground connection to

improve off-isolation, or as an additional input to switch matrix A.

2828 SA

MAX4550

FUNCTION

MAX4570

NAME

PIN

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

10 ______________________________________________________________________________________

Detailed Description

The MAX4550/MAX4570 are serial-interface, program­mable, dual 4x2 audio/video crosspoint switches. Each
device contains two independent 4x2 crosspoint
switches, controlled through the on-chip serial inter­face. The MAX4550 uses a 2-wire I2C-compatible serial
communications protocol, while the MAX4570 uses a
3-wire SPI/QSPI/MICROWIRE-compatible serial com­munications protocol.

These ICs include four controllable auxiliary outputs,
each capable of sourcing 1mA or sinking 12mA. Also
included are four selectable bias-resistor networks (one
for each output) for use with AC-coupled input signals.
Both devices operate with either ±5V dual supplies or a
single +5V supply, and are optimized for use in the
audio frequency range to 20kHz and at video frequen­cies up to 4MHz. They feature 80Ω on-resistance, 10Ω
on-resistance matching between channels, 5Ω on­resistance flatness, and as low as 0.004% total harmon­ic distortion.

The MAX4550/MAX4570 offer better than -110dB of
audio off-isolation, -95dB of audio crosstalk, -78dB of
video off-isolation, and -54dB of video crosstalk
(4MHz). The SA and SB (shunt) inputs further improve
off-isolation, allowing for the addition of external shunt
capacitors or the connection of outputs to AC grounds.
These devices feature a clickless operation mode for
noiseless audio switching. Clickless or standard switch­ing mode is selectable for each individual output using
the serial interface.

__________

Applications Information

The MAX4550/MAX4570 are divided into five functional
blocks: the control-logic block, two switch-matrix
blocks, the bias-resistor block, and the auxiliary-output
block (see

Functional Diagram

). The control-logic block
accepts commands via the serial interface and uses
those commands to control the four remaining blocks.

Command-Byte and Data-Byte

Programming

The devices are programmed through their serial inter­face with a command byte followed by a data byte.
Each bit of the command byte selects one of the func­tional blocks to be controlled by the subsequent data
byte. The data byte sets the state of the selected
block(s). For the two switch-matrix blocks, the data
byte sets the switch state. For the bias-resistor block,
the data byte controls which bias network is active. For
the auxiliary-output block, the data byte programs the
state of the four auxiliary outputs (see

Functional

Diagram

).

A logic “1” in any bit position of the data byte makes
that function active, while a logic “0” makes it inactive.
Tables 1–4 describe the command byte and the corre­sponding data byte. For example, if bit C4 of the com­mand byte is set, the subsequent data byte programs
the state of the auxiliary outputs. If bits D0 and D2 of
the subsequent data byte are set, Q0 and Q2 outputs
are set high. If more than one bit of the command byte
is set, the data byte programs all of the corresponding
blocks. This operation is useful, for instance, to simulta­neously set both switch matrices to the same configura­tion. Any block that is not selected in the command
byte remains unchanged.

Don’t careC7
Don’t careC6

BIT REGISTER

BIAS/MODEC5
AUXC4

COM2A

COM2BC3

C1

COM1AC0

COM1BC2

Don’t care

Don’t careD7

D5

Controls the switch connected to S_ ;
1 = close switch, 0 = open switch.

D4

Controls the switch connected to NO2_ ;
1 = close switch, 0 = open switch.

Don’t careD6

Controls the switch connected to NO4_ ;
1 = close switch, 0 = open switch.

D3

D1

Controls the switch connected to NO1_ ;
1 = close switch, 0 = open switch.

DESCRIPTION

D0

Controls the switch connected to NO3_ ;
1 = close switch, 0 = open switch.

D2

BIT

Table 2. COM Data-Byte Format
(C0, C1, C2, C3 = “1”)

Table 1. Command-Byte Format

Table 3. AUX_ Data-Byte Format (C4 = “1”)

Table 4. Clickless Mode/BIAS_ Data-Byte
Format (C5 = “1”)

2-Wire Serial Interface

The MAX4550 uses a 2-wire, fast-mode, I2C-compatible
serial interface. This protocol consists of an address
byte followed by the command and data bytes. To
address a given chip, the A0 and A1 bits in the
address byte must duplicate the values present at the
A0 and A1 pins of that chip. The rest of the address
bits control MAX4550 operation. The command and
data-byte details are described in the

Command-Byte

and Data-Byte Programming

section.

The 2-wire serial interface requires only two I/O lines of
a standard microprocessor port. Figures 1 and 2 detail
the timing diagram for signals on the 2-wire bus, and
Table 5 details the format of the signals. The MAX4550
is a receive-only device and must be controlled by a
bus master device. A bus master device communicates
by transmitting the address byte of the slave device
over the bus and then transmitting the desired informa­tion. Each transmission consists of a start condition, the
MAX4550’s programmable slave-address byte, a com­mand-byte, a data-byte, and finally a stop condition.
The slave device acknowledges the recognition of its
address by pulling the SDA line low for one clock peri­od after the address byte is transmitted. The slave
device also issues a similar acknowledgment after the
command byte and again after the data byte.

Start and Stop Conditions

The bus-master signals the beginning of a transmission
with a start condition by transitioning SDA from high to
low while SCL is high. When the master has finished
communicating with the slave, it issues a stop condition
by transitioning SDA from low to high while SCL is high.
The bus is then free for another transmission.

Slave Address (Address Byte)

The MAX4550 uses an 8-bit-long slave address. To
select a slave address, connect A0 and A1 to V+ or
GND. The MAX4550 has four possible slave addresses,
thus a maximum of four of these devices may share the
same 2-bit address bus. The slave device (MAX4550)
monitors the serial bus continuously, waiting for a start
condition followed by an address byte. When a slave
device recognizes its address (10011A1A00), it
acknowledges that it is ready for further communication
by pulling the SDA line low while SCL is high.

3-Wire Serial Interface

The MAX4570 3-wire serial interface is SPI/
QSPI/MICROWIRE-compatible. An active-low chip­select (CS) input enables the device to receive data
from the serial input (DIN). Data is clocked in on the ris­ing edge of the serial-clock (SCLK) signal. A total of 16
bits are needed in each write cycle. Segmented write
cycles are allowed (two 8-bit-wide transfers) if CS
remains low. The first bit clocked into the MAX4550 is
the command byte’s MSB, and the last bit clocked in is
the data byte’s LSB. While shifting data, the device
remains in its original configuration. After all 16 bits are
clocked into the input shift register, a rising edge on CS
latches the data into the MAX4570 internal registers,
initiating the device’s change of state.

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

______________________________________________________________________________________ 11

Don’t care

Don’t careD7

D5

Don’t careD4

Controls output Q1; 1 = set output high,
0 = set output low.

Don’t careD6

Controls output Q3; 1 = set output high,
0 = set output low.

D3

D1

Controls output Q0; 1 = set output high,
0 = set output low.

DESCRIPTION

D0

Controls output Q2; 1 = set output high,
0 = set output low.

D2

BIT

Controls COM2A clickless mode; 1 = enables
clickless mode, 0 = disables clickless mode.

Controls COM2B clickless mode; 1 = enables
clickless mode, 0 = disables clickless mode.

D7

D5

Controls COM1A clickless mode; 1 = enables
clickless mode, 0 = disables clickless mode.

D4

Controls COM2A bias resistors; 1 = connect bias
resistors, 0 = disconnect bias resistors.

Controls COM1B clickless mode; 1 = enables
clickless mode, 0 = disables clickless mode.

D6

Controls COM2B bias resistors; 1 = connect bias
resistors, 0 = disconnect bias resistors.

D3

D1

Controls COM1A bias resistors; 1 = connect bias
resistors, 0 = disconnect bias resistors.

DESCRIPTION

D0

Controls COM1B bias resistors; 1 = connect bias
resistors, 0 = disconnect bias resistors.

D2

BIT

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

12 ______________________________________________________________________________________

SCL

SDA

ACKACK

SRT

ACK

A7 D0D0

A0 D7 D7

STOP

Figure 1. 2-Wire Serial-Interface Timing Diagram

SCL

A B C D

E

F G

H

I

J

SDA

t

SU:STA

t

HD:STA

t

LOWtHIGH

t

SU:DAT

t

HD:DAT

t

SU:STO

t

BUF

A = START CONDITION
B = MSB OF ADDRESS BYTE
C = LSB OF ADDRESS BYTE
D = ACKNOWLEDGE CLOCKED INTO MASTER
E = MSB OF COMMAND BYTE

F = LSB OF COMMAND BYTE
G = ACKNOWLEDGE CLOCKED INTO MASTER
H = MSB OF DATA BYTE
I = LSB OF DATA BYTE
J = ACKNOWLEDGE CLOCKED INTO MASTER

Figure 2. 2-Wire Serial-Interface Timing Details

Table 5. 2-Wire Serial-Interface Data Format

0 1

A5A

4

ADDRESS BYTE

A00 B

I

A

S

A
U
X

1S
R
T

A1A

0

1 A

1

0

C5C

4

COMMAND BYTE

C
O
M
2
A

C
O
M

1

A

XA
C
K

C1C

0

C
O

M

2

B

C
O

M

1

B

A3A

2

X

C3C

2

C7C

6

D5D

4

D5D

4

DATA BYTE

D1D

0

D

7

A
C
K

D1D

0

D3D

2

D

6

D3D

2

D7D

6

A
C
K

A7A

6

X = Don’t care
SRT = Start condition
ACK = Acknowledge condition
STOP = Stop condition

S
T

O

P

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

______________________________________________________________________________________ 13

Figures 3, 4, and Table 6 show the details of the
3-wire protocol, as it applies to the MAX4570. DOUT is
the shift register’s output. Data at DOUT is simply the
input data delayed by 16 clock cycles, with data
appearing synchronous with SCLK’s falling edge.
Transitions at DIN and SCLK have no effect when CS is
high, and DOUT holds the last bit in the shift register.

Daisy Chaining

To program several MAX4570s, “daisy chain” the
devices by connecting DOUT of the first device to DIN of
the second, and so on. The CS pins of all devices are
connected together, and data is shifted through the
MAX4570s in series. 16 bits of data per device are
required for proper programming of all devices. When
CS is brought high, all devices are updated simultane­ously.

CS

SCLK

DIN

COMMAND BYTE DATA BYTE

16

1

C7 D0

C0 D7

Figure 3. 3-Wire Serial-Interface Communication

• • •

• • •

• • •

• • •

CS

SCLK

DIN

DOUT

t

CSH

t

CSS

t

CL

t

DS

t

DH

t

DV

t

CH

t

DO

t

TR

t

CSH

Figure 4. 3-Wire Serial-Interface Timing Details

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

14 ______________________________________________________________________________________

Addressable Serial Interface

To program several MAX4570s individually using a sin­gle processor, connect DIN of each MAX4570 together
and control CS on each MAX4570 separately. To select
a particular device, drive the corresponding CS low,
clock in the 16-bit command, then drive CS high and
execute the command. Typically, only one MAX4570 is
addressed at a time.

Improving Off-Isolation

To improve off-isolation, connect the SA or SB input to
ground either directly (DC ground) or through capaci­tors (AC ground). Closing SA or SB effectively grounds
the unused outputs.

Using the Internal Bias Resistors

Use the internal bias-resistor networks to give the
switch outputs a DC bias when the switch terminals are
AC coupled. Programming of the switches that connect
the bias resistors to the outputs is accomplished via bit
C5 of the command byte. Connect the BIASH and
BIASL inputs to DC levels (for example, V+ and GND),
and activate the switch connecting the appropriate out­put. This applies a voltage midway between V

BIASH

and V

BIASL

to the output (refer to Tables 1, 4, and the

Functional Diagram

).

Using the Auxiliary Outputs

The four auxiliary outputs provide a way to control
external circuitry, such as LEDs or other DC loads,
through the serial interface. Program these outputs via
bit C4 of the command byte. Each output is capable of
sourcing 1mA or sinking 12mA. They are programmed
through the command byte and data byte (refer to
Tables 1, 3, and the

Functional Diagram

).

Clickless Switching

Audible switching transients (“clicks”) are eliminated in
this mode of operation. When an output is configured
as “clickless,” the gate signal of the switches connect­ed to that output are controlled with slow-moving volt­ages. As a result, the output slew rates are significantly
reduced. Program clickless operation via bit C5 of the
command byte (refer to Tables 1, 4, and the

Functional

Diagram

). Each operating switch may draw as much as

2mA during transition.

Power-Up State

The MAX4550/MAX4570 feature a preset power-up
state. Upon power-up, COM1A and COM2A are con­nected to SA, COM1B and COM2B are connected to
SB, all outputs are set to clickless mode, all bias-resis­tor networks are disconnected from the outputs, and all
auxiliary outputs are low. All other switches are open.

Table 6. 3-Wire Serial-Interface Data Format

X = Don’t care

X

MSB

C6C7

AUXX

C4C5

BIAS COM1B

C2C3

COM1ACOM2B

C0C1

COM2A

COMMAND BYTE

D6
D6

D7 D4
D7 D4

D5
D5

D2
D2

D3

LSB

D0

D3 D0

DATA BYTE

D1
D1

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless

Audio/Video Analog Crosspoint Switches

______________________________________________________________________________________ 15

Functional Diagram

20

22
26

2
6

28

NO4A

NO3A

NO2A

NO1A

COM1A

SA

MAX4550
MAX4570

SWITCH MATRIX ‘A’

18

23
27

3
7
1

NO4B

NO3B

NO2B

NO1B

COM1B

9

COM2A

11

COM2B

SB

8, 24

V+

25

V-

21

GND

15

SDA/(DIN)

14

SCL/(SCLK)

13

A0/(CS)

16

A1/(DOUT)

4

BIASH

5

BIASL

10

Q0

12

Q1

17

Q2

19

Q3

SWITCH MATRIX ‘B’

BIAS RESISTOR NETWORK

10

AUXILIARY OUTPUTS

CONTROL

LOGIC

SWITCH STATES SHOWN IN POWER-UP STATE.
AUXILIARY OUTPUTS ARE LOW IN POWER-UP STATE.

( ) ARE FOR MAX4570

10

4

4

MAX4550/MAX4570

Serially Controlled, Dual 4x2, Clickless
Audio/Video Analog Crosspoint Switches

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

16

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© 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information

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