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SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
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General Description
The MAX4571–MAX4574 serial-interface controlled
switches are ideal for multimedia applications. Each
device features 35Ωmax on-resistance, -90dB audio
off-isolation at 20kHz, -60dB video off-isolation at
1.0MHz, and “clickless” mode operation for audio
applications.
The MAX4571/MAX4573 contain eleven SPST switches,
while the MAX4572/MAX4574 contain two SPST switch-
es and six SPDT switches. The MAX4571/MAX4572 fea-
ture a 2-wire, I2C™-compatible serial interface. The
MAX4573/MAX4574 feature a 3-wire, SPI™/QSPI™/
MICROWIRE™-compatible serial interface. All four
parts are available in 28-pin QSOP, SSOP, and wide
SO packages and operate over the commercial and
extended temperature ranges.
Applications
Set-Top Boxes Audio Systems
PC Multimedia Boards Video Conferencing Systems
Features
♦Selectable Soft Switching Mode for “Clickless”
Audio Operation
♦35Ωmax On-Resistance
♦-90dB Audio Off-Isolation at 20kHz
-50dB Video Off-Isolation at 10MHz
♦-90dB Audio Crosstalk at 20kHz
-52dB Video Crosstalk at 10MHz
♦Serial Interface
2-Wire, Fast-Mode, I2C-Compatible (MAX4571/72)
3-Wire, SPI/QSPI/MICROWIRE-Compatible
(MAX4573/74)
♦Single-Supply Operation from +2.7V to +5.25V
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video 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
V+
SDA (DOUT)
SCL (DIN)
A1 (SCLK)
A0 (CS)
GND
COM11
( ) ARE FOR MAX4573
NO8
COM8
NO9
COM9
NO10
COM10
NO11
COM7
NO7
COM6
NO6
COM5
NO5
COM4
NO4
COM3
NO3
COM2
NO2
COM1
NO1
QSOP/SSOP/SO
TOP VIEW
MAX4571/MAX4573
19-1404; Rev 1; 4/99
PART
MAX4571CEI
MAX4571CAI
MAX4571CWI 0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
28 QSOP
28 SSOP
28 Wide SO
Pin Configurations
Ordering Information
MAX4571EEI -40°C to +85°C 28 QSOP
MAX4571EAI -40°C to +85°C 28 SSOP
MAX4571EWI -40°C to +85°C 28 Wide SO
MAX4572CEI 0°C to +70°C 28 QSOP
MAX4572CAI 0°C to +70°C 28 SSOP
MAX4572CWI 0°C to +70°C 28 Wide SO
MAX4572EEI -40°C to +85°C 28 QSOP
MAX4572EAI -40°C to +85°C 28 SSOP
MAX4572EWI -40°C to +85°C 28 Wide SO
MAX4573CEI 0°C to +70°C 28 QSOP
MAX4573CAI 0°C to +70°C 28 SSOP
MAX4573CWI 0°C to +70°C 28 Wide SO
MAX4573EEI -40°C to +85°C 28 QSOP
MAX4573EAI -40°C to +85°C 28 SSOP
MAX4573EWI -40°C to +85°C 28 Wide SO
MAX4574CEI 0°C to +70°C 28 QSOP
MAX4574CAI 0°C to +70°C 28 SSOP
MAX4574CWI 0°C to +70°C 28 Wide SO
MAX4574EEI -40°C to +85°C 28 QSOP
MAX4574EAI -40°C to +85°C 28 SSOP
MAX4574EWI -40°C to +85°C 28 Wide SO
Pin Configurations continued at end of data sheet.
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS—Single +5V Supply
(V+ = +5V ±5%, TA= TMIN to TMAX, 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.
V+ to GND................................................................-0.3V to +6V
NO_ _, COM_, DOUT to GND (Note 1) ........-0.3V to (V+ + 0.3V)
SCL, SDA, CS, SCLK, DIN, A0, A1 to GND..............-0.3V to +6V
Continuous Current into Any Terminal..............................±10mA
Peak Current (pulsed at 1ms, 10% duty cycle)................±50mA
Continuous Power Dissipation (TA= +70°C)
QSOP (derate 10.8mW/°C above +70°C)...................860mW
SSOP (derate 9.5mW/°C above +70°C) .....................762mW
Wide SO (derate 12.5mW/°C above +70°C).............1000mW
Operating Temperature Ranges
MAX457_C_ _ ....................................................0°C to +70°C
MAX457_E_ _..................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
VNO_ _ = 4.5V, 1V;
VCOM_ = 1V, 4.5V;
V+ = 5.25V
ICOM_ = 4mA;
V+ = 4.75V;
VNO_ _ = 1V, 2V, 3V
ICOM_ = 4mA,
VNO_ _ = 3V,
V+ = 4.75V
CONDITIONS
V0V+
VNO_ _,
VCOM_
ANALOG SWITCHES
Analog Signal Range (Note 3)
nA
-0.2 0.01 0.2
INO_ _ (OFF)
NO_ _ Off-Leakage
Current (Note 6)
Ω
2 6
RFLAT
On-Resistance
Flatness (Note 5)
Ω
25 35
RON
On-Resistance 45
Ω
0.8 3
∆RON
On-Resistance Match
Between Channels (Note 4)
UNITSMIN TYP MAXSYMBOLPARAMETER
COM_ Off-Leakage
Current (Note 6) ICOM_ (OFF) VNO_ _ = 4.5V, 1V;
VCOM_ = 1V, 4.5V;
V+ = 5.25V
-0.2 0.01 0.2 nA
COM _ On-Leakage
Current (Note 6) ICOM_ (ON) VCOM_ = 4.5V, 1V;
VNO_ _ = 4.5V, 1V, or
floating; V+ = 5.25V
-0.2 0.01 0.2 nA
AUDIO PERFORMANCE
Total Harmonic Distortion
plus Noise THD+N fIN = 1kHz, RL = 600Ω, VNO_ _ = 1VRMS,
VNO_ _ = 2.5V 0.07 %
Off-Isolation (Note 7) VISO(A) VNO_ _ = 1VRMS, fIN = 20kHz,
RL= 600Ω, Figure 1 -90 dB
Channel-to-Channel Crosstalk VCT(A) VNO_ _ = 1VRMS, fIN = 20kHz,
RS= 600Ω, Figure 1 -90 dB
ICOM_ = 4mA,
VNO_ _ = 3V,
V+ = 4.75V
TA= +25°C
TA= TMIN to TMAX
TA= +25°C
TA= +25°C
TA= +25°C
TA= +25°C
TA= +25°C
3
TA= TMIN to TMAX
TA= TMIN to TMAX 6
TA= TMIN to TMAX
TA= TMIN to TMAX
TA= TMIN to TMAX -10 10
-10 10
-10 10
ANALOG SWITCHES
AUDIO PERFORMANCE
Note 1: Signals on NO_ _ or COM_ exceeding V+ or V- are clamped by internal diodes. Limit forward-diode current to maximum
current rating.
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS—Single +5V Supply (continued)
(V+ = 5V ±5%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
ELECTRICAL CHARACTERISTICS—Single +3V Supply
(V+ = 3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
ICOM_ = 4mA,
VNO_ _ =2V,
V+ = 2.7V
TA= +25°C
TA= TMIN to TMAX
TA= +25°C
5TA= TMIN to TMAX
ICOM_ = 4mA,
VNO_ _ = 2V,
V+ = 2.7V
CONDITIONS
V0V+
VNO_ _,
VCOM_
ANALOG SWITCHES
Analog Signal Range (Note 3)
Ω
43 90
RON
On-Resistance 110
Ω
15
∆RON
On-Resistance Match
Between Channels (Note 4)
UNITSMIN TYP MAXSYMBOLPARAMETER
ANALOG SWITCHES
VNO_ _ = 1.5V,
RL= 5kΩ,
CL= 35pF
TA= +25°C
TA= TMIN to TMAX
TA= +25°C
400
fIN = 1MHz
All logic inputs = 0 or V+,
TA= TMIN to TMAX
MAX4572/MAX4574, VNO_ _ = 1.5V,
TA= TMIN to TMAX
TA= TMIN to TMAX
VNO_ _ = 1.5V,
RL= 300Ω,
CL= 35pF
CONDITIONS
pF9COFF(NO)
Off-Capacitance
µA610I+Supply Current (Note 9)
ns10 125tBBM
Break-Before-Make Time
ns
200 500
tONSD
Turn-On Time 700
ns
75 300
tOFFSD
Turn-Off Time
UNITSMIN TYP MAXSYMBOLPARAMETER
TA= TMIN to TMAX V+2.7 +5.25V+Supply Voltage Range
VNO_ _ or = 1.5V, RL= 300Ω, CL= 35pF,
TA= +25°C ms3tOFFSE
Turn-Off Time
VNO_ _ = 1.5V, RL= 5kΩ, CL= 35pF,
TA= +25°C ms8tONSE
Turn-On Time
RSOURCE = 50Ω, RL= 50ΩMHz>150BW-3dB Bandwidth
VNO_ _ = 1VRMS, fIN = 1.0MHz,
RS= 50Ω, Figure 1 dB-52VCT(V)
Channel-to-Channel Crosstalk
VNO_ _ = 1VRMS, fIN = 1.0MHz,
RL= 50Ω, Figure 1 dB-50VISO(V)
Off-Isolation (Note 7)
DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Notes 8 and 12, Figure 2)
DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Note 8, Figure 2)
POWER SUPPLY
VIDEO PERFORMANCE
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—Single +3V Supply (continued)
(V+ = +3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
ns
TA= +25°C
TA= +25°C
TA= TMIN to TMAX -10 10
TA= TMIN to TMAX
CONDITIONS
COM _ On-Leakage
Current (Notes 6 and 10) ICOM_ (ON)
VCOM_ = 3V, 0.5V;
VNO_ _ = 3V, 0.5V,
or floating;
V+ = 3.6V
-0.2 0.01 0.2 nA
Total Harmonic Distortion
plus Noise THD+N fIN = 1kHz, RL = 600Ω, VNO_ = 0.5VRMS,
VNO_ _ = 1.5V 0.07 %
Off-Isolation (Note 7) VISO(A) VNO_ _ = 0.5VRMS, fIN = 20kHz, RL= 600Ω,
Figure 1 -90 dB
Channel-to-Channel Crosstalk VCT(A) VNO_ _ = 0.5VRMS, fIN = 20kHz, RS= 600Ω,
Figure 1 -90 dB
UNITSMIN TYP MAXSYMBOLPARAMETER
Off-Isolation (Note 7) VISO(V) VNO_ _ = 0.5VRMS, fIN = 10MHz, RL= 50Ω,
Figure 1 -50 dB
Channel-to-Channel Crosstalk VCT(V) VNO_ _ = 0.5VRMS, fIN = 10MHz, RS= 50Ω,
Figure 1 -52 dB
-3dB Bandwidth BW RSOURCE = 50Ω, RL= 50Ω, CL= 35pF >150 MHz
Off Capacitance COFF(NO) fIN = 1MHz 9 pF
Turn-On Time tONSD VNO_ _ = 1.5V,
RL= 5kΩ, CL= 35pF 300 900 ns
1000
TA= +25°C
TA= TMIN to TMAX 10
On-Resistance
Flatness (Note 5) RFLAT ICOM_ = 4mA;
V+= 2.7V;
VNO_ _ = 1V, 5V, 2V
410Ω
TA= +25°C
TA= TMIN to TMAX
Turn-Off Time tOFFSD VNO_ _ = 1.5V,
RL= 300Ω, CL= 35pF 100 300
400
VNO_ _ = 1.5V, TA= TMIN to TMAX
Break-Before-Make Time tBBM 10 200 ns
VNO_ _ = 1.5V, RL= 5kΩ, CL= 35pF,
TA= +25°C
Turn-On Time tONSE 8 ms
VNO_ _ = 1.5V, RL= 300Ω, CL= 35pF,
TA= +25°C
Turn-Off Time tOFFSE 3 ms
TA= +25°C
TA= TMIN to TMAX -10 10
COM_ Off-Leakage
Current (Notes 6 and 10) ICOM_ (OFF) VNO_ _ = 3V, 0.5V;
VCOM_ = 0.5V, 3V;
V+ = 3.6V
-0.2 0.01 0.2 nA
TA= +25°C
TA= TMIN to TMAX -10 10
NO_ _Off-Leakage
Current (Notes 6 and 10) INO_ _ (OFF) VNO_ _ = 3V, 0.5V;
VCOM_ = 0.5V, 3V;
V+ = 3.6V
-0.2 0.01 0.2 nA
AUDIO PERFORMANCE
VIDEO PERFORMANCE
DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Notes 8 and 12, Figure 2)
DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Notes 8 and 12, Figure 2)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
_______________________________________________________________________________________ 5
pF5CIN
Input Capacitance
V0.2VHYST
Input Hysteresis
UNITSMIN TYP MAXCONDITIONSSYMBOLPARAMETER
µA-1 0.01 1Digital inputs = 0 or V+ILEAK
Input Leakage Current
V+ = 3V
V+ = 3V 0.6
2V
3V+ = 5V
VIH
Input High Voltage
V
0.8V+ = 5V
VIL
Input Low Voltage
ns
20 + 300
0.1Cb
(Note 11)tF
SCL/SDA Fall Time
ns
20 + 300
0.1Cb
(Note 11)tR
SCL/SDA Rise Time
µs0.6tHIGH
Clock High Period µs1.3tLOW
Clock Low Period ns100tSU:DAT
Data Setup Time µs0 0.9tHD:DAT
Data Hold Time
µs0.6tHD:STA
START Condition Hold Time
µs1.3tBUF
Bus Free Time between Stop
and Start Condition
kHzDC 400fSCL
SCL Clock Frequency
V
V+
- 0.5
ISOURCE = 0.5mAVOH
DOUT Output High Voltage
ns0tDH
DIN to SCLK Hold
MHzDC 2.1fOP
Operating Frequency ns100tDS
DIN to SCLK Setup
ns20 200CLOAD = 50pFtDO
SCLK Fall to Output Data Valid
I/O INTERFACE CHARACTERISTICS
(V+ = +2.7V to +5.25V, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
V0.4ISINK = 6mAVOL
Output Low Voltage
ns100tCSS
CS to SCLK Rise Setup
µs2tR
Rise Time (SCLK, DIN, CS)
ns0tCSH
CS to SCLK Rise Hold
ns200tCL
SCLK Pulse Width Low
µs2tF
Fall Time (SCLK, DIN, CS)
µs0.6tSU:STO
STOP Condition Setup Time
ns200tCSW
CS High Pulse Width
ns200tCH
SCLK Pulse Width High
DIGITAL INPUTS (SCLK, DIN, CS, SCL, SDA, A0, A1)
DIGITAL OUTPUTS (DOUT, SDA)
2-WIRE INTERFACE TIMING (Figure 3)
3-WIRE TIMING (Figure 5)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
6 _______________________________________________________________________________________
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: ∆RON = RON(MAX) - RON(MIN).
Note 5: 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 TA= +25°C.
Note 7: Off-isolation = 20 log [VCOM_ / VNO_ _ ], VCOM_ = output, VNO_ _ = input to off switch.
Note 8: All timing is measured from the rising clock edge of the ACK bit for 2-wire, and from the rising edge of CS for 3-wire. Turn-
off time is defined at the output of the switch for a 0.5V change, tested with a 300Ωload to ground. Turn-on time is mea-
sured with a 5kΩload resistor to GND. All timing is shown with respect to 20% V+ and 70% V+, unless otherwise noted.
Note 9: Supply current can be as high as 2mA per switch during switch transitions in the clickless mode, corresponding to a 28mA
total supply transient current requirement.
Note 10: Leakage testing for single-supply operation is guaranteed by testing with a single +5.25V supply.
Note 11: Cb= capacitance of one bus line in pF. Tested with Cb= 400pF.
Note 12: Typical values are for MAX4573/MAX4574 devices.
20
30
25
40
35
45
50
021 345
ON-RESISTANCE vs. VCOM
MAX4571-4 toc01
VCOM (V)
ON-RESISTANCE (Ω)
V+ = 2.7V
V+ = 3.3V
V+ = 5.0V
18
22
20
26
24
30
28
32
021 345
ON-RESISTANCE vs.
VCOM AND TEMPERATURE
MAX4571-4 toc02
VCOM (V)
ON-RESISTANCE (Ω)
TA = +85°C
TA = +70°C
TA = +25°C
TA = -40°C
0.001
0.01
1
0.1
10
100
-40 0-20 20 40 60 80
LEAKAGE CURRENT vs. TEMPERATURE
MAX4571-4 toc03
TEMPERATURE (°C)
CURRENT (nA)
COM_ OFF
NO_ _ OFF
NO_ _ ON
4.5
4.6
4.9
4.8
4.7
5.0
5.1
-40 0-20 20 40 60 80
SUPPLY CURRENT vs. TEMPERATURE
MAX4571-4 toc04
TEMPERATURE (°C)
CURRENT (µA)
-3
-2
1
0
-1
2
3
012345
CHARGE INJECTION vs. VCOM
MAX4571-4 toc05
VCOM (V)
Q (pC)
0
100
400
300
200
500
600
-40 0-20 20 40 60 80
ON/OFF TIME vs. TEMPERATURE
(HARD MODE)
MAX4571-4 toc06
TEMPERATURE (°C)
TIME (ns)
tON, V+ = 5V
tOFF, V+ = 5V
tON, V+ = 3V
tOFF, V+ = 3V
Typical Operating Characteristics
(V+ = +5V, TA = +25°C, unless otherwise noted.)
TIME (50ns/div)
ON/OFF TIMES
(HARD MODE)
MAX4571-4 toc13
CS
5V/div
tON
1V/div
tOFF
1V/div
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
_______________________________________________________________________________________
7
10,000 100,000
0.01
0.1
1
10 100 1000
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX4571-4 toc07
FREQUENCY (Hz)
THD + N (%)
600Ω IN AND OUT
SIGNAL = 1VRMS
10,000 100,000
-120
-60
0
-20
-40
-80
-100
10 100 1000
AUDIO FREQUENCY RESPONSE
MAX4571-4 toc08
FREQUENCY (Hz)
LOSS (dB)
600Ω IN AND OUT
CROSSTALK
OFF-ISOLATION
-100 0.1 100101
VIDEO FREQUENCY RESPONSE
0
-60
-80
-20
-40
MAX4571-4 toc09
FREQUENCY (MHz)
LOSS (dB)
INSERTION-LOSS
OFF-ISOLATION
CROSSTALK
50Ω IN AND OUT
Typical Operating Characteristics (continued)
(V+ = 5V,TA= +25°C, unless otherwise noted.)
TIME (2ms/div)
ON/OFF TIMES
(SOFT MODE)
MAX4571-4 toc10
CS
5V/div
tON
tOFF
1V/div
1V/div
TIME (500µs/div)
SOFT MODE RISE TIME
MAX4571-4 toc11
AMPLITUDE (500mV/div)
TIME (500µs/div)
SOFT MODE FALL TIME
MAX4571-4 toc12
AMPLITUDE (500mV/div)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
8 _______________________________________________________________________________________
Pin Descriptions
FUNCTION
MAX4571 MAX4572
1, 3, 5, 7, 9,
11, 13, 22, 20,
18, 16 – Normally Open Terminals
PIN
– 1, 4, 7, 10 Normally Open Terminals
23 23 Ground
27 27 Data Input of 2-Wire Serial Interface
26 26 Clock Input of 2-Wire Serial Interface
25 25 LSB + 2 of 2-Wire Serial Interface Address Field
24 24 LSB + 1 of 2-Wire Serial Interface Address Field
28 28 Positive Supply Voltage
MAX4571 MAX4572
NO1–NO11 –
NAME
– NO1A–NO4A
GND GND
SDA SDA
SCL SCL
A1 A1
A0 A0
V+ V+
2, 4, 6, 8, 10,
12, 14, 21, 19,
17, 15
2, 5, 8, 11, 14,
21, 18, 15 Common TerminalsCOM1–COM11 COM1–COM8
– 3, 6, 9, 12 Normally Open Terminals– NO1B–NO4B
– 13, 16 Normally Open Terminals– NO5, NO8
– 22, 19, 20, 17 Normally Open Terminals– NO6A, NO7A,
NO6B, NO7B
2, 4, 6, 8, 10,
12, 14, 21, 19,
17, 15
FUNCTION
MAX4573 MAX4574
2, 5, 8, 11, 14,
21, 18, 15
1, 3, 5, 7, 9,
11, 13, 22, 20,
18, 16 – Normally Open Terminals
PIN
– 1, 4, 7, 10 Normally Open Terminals
23 23 Ground
27 27 Data Output of 3-Wire Serial Interface
26 26 Clock Input of 3-Wire Serial Interface
25 25 Clock Input of 3-Wire Serial Interface
24 24 Chip Select of 3-Wire Serial Interface
Common TerminalsCOM1–COM11 COM1–COM8
– 3, 6, 9, 12 Normally Open Terminals– NO1B–NO4B
– 13, 16 Normally Open Terminals–
28 28 Positive Supply Voltage
NO5, NO8
MAX4573 MAX4574
NO1–NO11 –
NAME
– NO1A–NO4A
GND GND
DOUT DOUT
DIN DIN
SCLK SCLK
CS CS
– 22, 19, 20, 17 Normally Open Terminals– NO6A, NO7A,
NO6B, NO7B
V+ V+
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
_______________________________________________________________________________________ 9
Figure 2. Switching Time
DECODER/
CONTROLLER DECODER/
CONTROLLER
2/3
SIGNAL
GENERATOR 0dBm
V+
10nF
ANALYZER
NO_ _
RL
GND
COM_V+
2/3
SIGNAL
GENERATOR 0dBm
V+
10nF
a) Off-Isolation b) Crosstalk
NO2
GND
COM1 NO1 50Ω
COM2 N.C.
ANALYZER
RL
V+
MAX4571
MAX4572
MAX4573
MAX4574
MAX4571
MAX4572
MAX4573
MAX4574
RL
300ΩCL
35pF
VOUT
NO
V+
V+
GND
CL INCLUDES FIXTURE AND STRAY CAPACITANCE
VOUT = VCOM [RL / (RL + RON)]
2 OR 3
SERIAL
INTERFACE
DECODER/
CONTROLLER
µP
3-Wire
2-Wire
SCL
CS
3V
0
VOUT
0
VOUT
0
3V
0
VOUT
0
VOUT
0
50%
50%
tON
tON
tOFF
tOFF
0.9 • VOUT
0.1 • VOUT
0.9 • VOUT
0.1 • VOUT
tr < 20ns
tf < 20ns
ACKNOWLEDGE
BIT
NO_ _ COM_
MAX4571
MAX4572
MAX4573
MAX4574
Figure 1. Off-Isolation and Crosstalk
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
10 ______________________________________________________________________________________
Detailed Description
The MAX4571–MAX4574 are serial-interface controlled
switches with soft-mode “clickless” and hard-mode oper-
ating capability. The MAX4571/MAX4573 contain 11
SPST switches, while the MAX4572/MAX4574 contain
two SPST switches and six SPDT switches. The SPDT
switches are actually 2-to-1 multiplexers, in that each
SPDT is really two independent SPST switches with a
common node, as shown in the
Pin Configurations
. Each
switch is controlled independently by either the SPI or
I2C interface.
Audio off-isolation is -90dB at 20kHz, crosstalk is at
least -90dB at 20kHz, and video off-isolation is at least
-50dB at 10MHz.
Each switch of any device may be set to operate in
either soft or hard mode. In soft mode, the switching
transition is slowed to avoid the audible “clicking” that
can occur when switches are used to route audio sig-
nals. In hard mode, the switches are not slowed down,
making this mode useful when a faster response is
required. If a new command is issued while any soft-
mode switch is transitioning, the switch transition time
is decreased so it reaches its final state before the new
command is executed. Soft mode is the power-up
default state for all switches. Switches in the same
mode are guaranteed to be break-before-make relative
to each other. Break-before-make does not apply
between switches operating in different modes.
These devices operate from a single supply of +2.7V to
+5.25V. The MAX4571/MAX4572 feature a 2-wire, I2C-
compatible serial interface, and the MAX4573/
MAX4574 feature a 3-wire, SPI/QSPI/MICROWIRE-com-
patible serial interface.
Applications Information
Switch Control
The MAX4571–MAX4574 have a common command
and control-bit structure, the differences being only in
the interface type (2-wire or 3-wire) and in the switch
configurations.
The SWITCHSET command controls the open/closed
states of the various switches. MODESET controls
soft/hard-mode states of the switches. There are also
NO_OP and RESET commands. The NO_OP command
is useful for daisy-chaining multiple 3-wire parts. The
RESET command places a device in a state identical to
its power-up state, with all switches open and in soft
switching mode.
Table 1 shows the configuration of the command bits
and their related commands. Table 2 shows the config-
uration of the data bits and their related switches. The
arrangement of the command bits and the data bits
depends on the interface type (2-wire or 3-wire). After a
SWITCHSET command is issued, a logic 1 in any data-
bit location closes the associated switch, while a logic 0
opens it. After a MODESET command, a logic 1 in any
data-bit location sets the associated switch into hard
mode, while a logic 0 sets it into soft mode.
2-Wire Serial Interface
The MAX4571/MAX4572 use a 2-wire, I2C-compatible
serial interface requiring only two I/O lines of a stan-
dard microprocessor port for communication. These
devices use the SendByte™ and WriteWord™ proto-
cols. The SendByte protocol is used only for the RESET
command. The WriteWord protocol is used for the
MODESET and SWITCHSET commands.
The first byte of any 2-wire serial-interface transaction is
always the address byte. To address a given chip, the
A0 and A1 bits in the address byte (Table 3) must dupli-
cate the values present at the A0 and A1 pins of that
chip, and the rest of the address bits must be config-
ured as shown in Table 3. Connect the A0 and A1 pins
to V+ or to GND, or drive them with CMOS logic levels.
The second byte is the command byte. The possible
commands are RESET, MODESET, and SWITCHSET.
RESET sets all switches to the initial power-up state
(open and in soft switching mode). The RESET com-
mand is executed on the rising clock edge of the
acknowledge bit after the command byte. The MODE-
SET and SWITCHSET commands are each followed by
two data bytes. The first data byte is buffered so all the
data latches switch together. MODESET and SWITCH-
SET are executed on the rising clock edge of the
acknowledge bit after the second data byte. Table 3
details the 2-wire interface data structure. Figures 3
and 4 and the
I/O Interface Characteristics
detail the
timing of the 2-wire serial-interface protocol. All bytes of
the transmission, whether address, command, or data,
are sent MSB first.
The MAX4571/MAX4572 are receive-only devices and
must be controlled by a bus master device. A bus mas-
ter signals the beginning of a transmission with a start
condition by transitioning SDA from high to low while
SCL is high. The slave devices monitor the serial bus
continuously, waiting for a start condition followed by an
address byte. When a device recognizes its address
byte, it acknowledges by pulling the SDA line low for
one clock period; it is then ready to accept command
and data bytes. The device then issues a similar
acknowledgment after the command byte, and again
after each data byte. When the master has finished
SendByte and WriteWord are trademarks of Philips Corp.
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
______________________________________________________________________________________ 11
Table 1. Command Bit Mapping
Table 2. Data-Bit Switch Control
X = Don’t care
MSB MSB - 1 COMMAND DESCRIPTION
0 0 RESET Sets all switches open and in soft switching mode.
0 1 MODESET Sets specified switches to soft or hard mode.
1 0 NO_OP No Operation.
1 1 SWITCHSET Sets specified switches open or closed.
D13 X SW8
D12 X SW5
D11 X SW7B
D10 15, 16 SW7A
D8 19, 20 SW6A
X
X
X
SW11
SW9
15, 16
13, 14
17, 18
18, 19
21, 22
D7 21, 22 SW4B
D6 13, 14 SW4A
D5 11, 12 SW3B
D4 9, 10 SW3A
D3 7, 8 SW2B
SW8
SW7
SW6
SW5
SW4
11, 12
10, 11
8, 9
7, 8
5, 6
D2 5, 6 SW2A
D1 3, 4 SW1B
D0 (LSB) 1, 2 SW1A
SW3
SW2
SW1
4, 5
2, 3
1, 2
DATA BIT SWITCHSWITCH
D9 17, 18 SW6BSW10 20, 21
SWITCH TERMINALS SWITCH TERMINALS
MAX4572/MAX4574MAX4571/MAX4573
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.
3-Wire Serial Interface
The MAX4573/MAX4574 use a 3-wire SPI/QSPI/
MICROWIRE-compatible serial interface. An active-low
chip-select pin, CS, enables the device to receive data
from the serial input pin, DIN. Command and data infor-
mation are clocked in on the rising edge of the serial-
clock signal (SCLK) MSB first. A total of 16 bits are
needed in each write cycle. The write cycle allows two
8-bit-wide transfers if CS remains low for the entire 16
bits. The command code is contained in the two MSBs
of the 16-bit word. The remaining bits control the
switches as shown in Table 4. While shifting in the seri-
al data, the device remains in its original configuration.
A rising edge on CS latches the data into the
MAX4573/MAX4574 internal registers, initiating the
device’s change of state. Table 4 shows the details of
the 3-wire interface data structure.
Figures 5 and 6 and the
I/O Interface Characteristics
show the timing details of the 3-wire interface. If the
two command bits initiate a SWITCHSET command, a
logic 1 in a switch control location closes the associat-
ed switch, while a logic 0 opens it. If the command bits
initiate a MODESET command, a logic 1 in a switch
control location sets the associated switch into hard
mode, while a logic 0 sets it into soft, “clickless” mode.
For command-bit configurations, see Table 1.
Using Multiple Devices
There are two ways to connect multiple devices to the
same 3-wire serial interface. The first involves using the
DOUT pin. DOUT presents a copy of the last bit of the
internal shift register, useful for daisy-chaining multiple
devices. Data at DOUT are simply the input data
delayed by 16 clock cycles, appearing synchronous
with SCLK’s falling edge. After CS goes high, DOUT
holds the last bit in the shift register until new data are
shifted into DIN. For a simple interface using several
MAX4573/MAX4574 devices, daisy-chain the shift reg-
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
12 ______________________________________________________________________________________
Address Byte Command Byte (RESET)
MSB
S
R
T
01101A
1A
00A
C
K
00XXXXXXA
C
K
S
T
P
XXXXXSW
11 SW
10 SW
9A
C
K
SW
8SW
7SW
6SW
5SW
4SW
3SW
2SW
1A
C
K
S
T
P
XXSW
8SW
5SW
7B SW
7A SW
6B SW
6A A
C
K
SW
4B SW
4A SW
3B SW
3A SW
2B SW
2A SW
1B SW
1A A
C
K
S
T
P
XXSW
8SW
5SW
7B SW
7A SW
6B SW
6A A
C
K
SW
4B SW
4A SW
3B SW
3A SW
2B SW
2A SW
1B SW
1A A
C
K
S
T
P
XXXXXSW
11 SW
10 SW
9A
C
K
SW
8SW
7SW
6SW
5SW
4SW
3SW
2SW
1A
C
K
S
T
P
S
R
T
01101A
1A
00A
C
K
1
1XXXXXXA
C
K
S
R
T
01101A
1A
00A
C
K
01XXXXXXA
C
K
LSB
LSB
LSB
MSB LSB
Command Byte (SWITCHSET)
Command Byte (MODESET)
MSB LSB
MSB LSB
Address Byte
First Data Byte
MSB
MSB LSB
Second Data Byte
MSB
LSB
First Data Byte
MSB LSB
Second Data Byte
MSB
MSB
LSB
First Data Byte
MSB LSB
Second Data Byte
MSB
MSB
Address Byte
MSB
MSB
LSB
First Data Byte
MSB LSB
Second Data Byte
MSB
MSBMSB
MSB
X = Don't Care
SRT = Start Condition
ACK = Acknowledge Condition
STP = Stop Condition
Logic "0" in any data bit location places the associated switch open or in soft (clickless) switching mode.
Logic "1" in any data bit location places the associated switch closed or in hard switching mode.
For command bit configuration see Table 1.
RESET Command
SWITCHSET Command
MAX4571
MAX4572
MAX4571
MAX4572
MODESET Command
Table 3. 2-Wire Serial-Interface Data Format
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
______________________________________________________________________________________ 13
SCL
SDA
tLOW
tHIGH
tF
tR
tHD, STA
tHD, DAT
tHD, STA
tSU, DAT tSU, STA tBUF
tSU, STO
START CONDITIONSTOP CONDITIONREPEATED START CONDITIONSTART CONDITION
20% 70% 20%
70% 20% 70%
20% 70%
20%
70%
20%
70% 20%
70% 70%
20%
70% 70% 70%
Figure 3. 2-Wire Serial-Interface Timing Diagram
START CONDITION STOP CONDITION
FIRST DATA BYTE SECOND DATA BYTE
COMMAND BYTE
ADDRESS BYTE
SCL
SDA MSB MSB MSB MSBLSB LSB LSB LSB
ACK ACK ACK ACK
Figure 4. A Complete 2-Wire Serial-Interface Transmission
Table 4. 3-Wire Serial-Interface Data Format
D15
C1 D14
C0 D12
X
D13
XD10
SW11
D11 D8
SW9X D9
SW10 D6
SW7
D7 D4
SW5SW8 D5
SW6 D2
SW3
MAX4573 (11 SPST)
D3 D0
SW1SW4 D1
SW2
COMMAND SWITCH CONTROL
MSB LSB
COMMAND
D14
C0
D15 D12
SW5C1 D13
SW8 D10
SW7A
D11 D8
SW6ASW7B
SWITCH CONTROL
D9
SW6B D6
SW4A
D7 D4
SW3ASW4B D5
SW3B D2
SW2A
MAX4574 (6 SPDT + 2 SPST)
D3 D0
SW1ASW2B
MSB LSB
D1
SW1B
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
14 ______________________________________________________________________________________
SCLK
DIN
DOUT
tCSS tCL tCH
tCSW tCSO
tDO
tCSH
tDH
tDS
D15 D14 D1 D0
CS 20%
20% 20% 20% 20% 20%
20%
70% 70%
70%
70%
Figure 5. 3-Wire Serial-Interface Timing Diagram
SCLK
DIN
CS
LSB FROM
PREVIOUS WRITE
MSB FROM
PREVIOUS WRITE
COMMAND
EXECUTED
9
Q15........
MSB
D15 D14 D13....
.........00
816
1
DOUT
LSB
D1D2 D0....
Figure 6. A Complete 3-Wire Serial-Interface Transmission
isters by connecting DOUT of the first device to DIN of
the second, etc. Connect the CS pins of all devices
together. Data are shifted through the MAX4573/
MAX4574s in series. When CS is brought high, all
devices are updated simultaneously. If any of the
devices in the chain are to be left unchanged, use a
NO_OP command for that device, as shown in Table 1.
An alternate way of connecting multiple devices is to
decode the CS line. In this case the DOUT pin is not
used and the DIN pins of all devices are connected
together. Address decode logic individually controls the
CS line of each device. When a device is to be selected
its CS line is brought low, data are shifted in, and its CS
is then brought high to execute the command.
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
______________________________________________________________________________________ 15
TRANSISTOR COUNT: 5397
___________________Chip InformationPin Configurations (continued)
Package Information
QSOP.EPS
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video 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
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information (continued)
SSOP.EPS
SOICW.EPS