19-1404; Rev 1; 4/99
Serially Controlled, Clickless
Audio/Video Switches
The MAX4571–MAX4574 serial-interface controlled
switches are ideal for multimedia applications. Each
device features 35Ω max 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 switches and six SPDT switches. The MAX4571/MAX4572 feature a 2-wire, I 2C™-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.
Features
♦ Selectable Soft Switching Mode for “Clickless”
Audio Operation
♦ 35Ω max 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
Ordering Information
Applications
Set-Top Boxes
Audio Systems
PC Multimedia Boards
Video Conferencing Systems
Pin Configurations
TOP VIEW
MAX4571/MAX4573
NO1 1
28 V+
COM1 2
27 SDA (DOUT)
NO2 3
26 SCL (DIN)
COM2 4
25 A1 (SCLK)
NO3 5
24 A0 (CS)
COM3 6
23 GND
NO4 7
22 NO8
COM4 8
21 COM8
NO5 9
20 NO9
COM5 10
19 COM9
NO6 11
18 NO10
COM6 12
NO7 13
COM7 14
( ) ARE FOR MAX4573
17 COM10
16 NO11
PART
TEMP. RANGE
MAX4571CEI
0°C to +70°C
MAX4571CAI
MAX4571CWI
MAX4571EEI
MAX4571EAI
MAX4571EWI
MAX4572CEI
MAX4572CAI
MAX4572CWI
MAX4572EEI
MAX4572EAI
MAX4572EWI
MAX4573CEI
MAX4573CAI
MAX4573CWI
MAX4573EEI
MAX4573EAI
MAX4573EWI
MAX4574CEI
MAX4574CAI
MAX4574CWI
MAX4574EEI
MAX4574EAI
MAX4574EWI
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
28 QSOP
28 SSOP
28 Wide SO
15 COM11
QSOP/SSOP/SO
Pin Configurations continued at end of data sheet.
I2C is a trademark of Philips Corp.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX4571–MAX4574
General Description
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
ABSOLUTE MAXIMUM RATINGS
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
Note 1: Signals on NO_ _ or COM_ exceeding V+ or V- are clamped by internal diodes. Limit forward-diode current to maximum
current rating.
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.
ELECTRICAL CHARACTERISTICS—Single +5V Supply
(V+ = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V+
V
ANALOG SWITCHES
Analog Signal Range (Note 3)
On-Resistance
VNO_ _,
VCOM_
RON
On-Resistance Match
Between Channels (Note 4)
∆RON
On-Resistance
Flatness (Note 5)
RFLAT
NO_ _ Off-Leakage
Current (Note 6)
INO_ _ (OFF)
COM_ Off-Leakage
Current (Note 6)
ICOM_ (OFF)
COM _ On-Leakage
Current (Note 6)
ICOM_ (ON)
0
ICOM_ = 4mA,
VNO_ _ = 3V,
V+ = 4.75V
TA = +25°C
ICOM_ = 4mA,
VNO_ _ = 3V,
V+ = 4.75V
TA = +25°C
ICOM_ = 4mA;
V+ = 4.75V;
VNO_ _ = 1V, 2V, 3V
TA = +25°C
VNO_ _ = 4.5V, 1V;
VCOM_ = 1V, 4.5V;
V+ = 5.25V
TA = +25°C
-0.2
TA = TMIN to TMAX
-10
VNO_ _ = 4.5V, 1V;
VCOM_ = 1V, 4.5V;
V+ = 5.25V
TA = +25°C
-0.2
TA = TMIN to TMAX
-10
VCOM_ = 4.5V, 1V;
VNO_ _ = 4.5V, 1V, or
floating; V+ = 5.25V
TA = +25°C
-0.2
TA = TMIN to TMAX
-10
25
TA = TMIN to TMAX
35
Ω
45
0.8
3
Ω
3
TA = TMIN to TMAX
2
TA = TMIN to TMAX
6
Ω
6
0.01
0.2
nA
10
0.01
0.2
nA
10
0.01
0.2
nA
10
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
2
_______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
VIDEO PERFORMANCE
Off-Isolation (Note 7)
VISO(V)
VNO_ _ = 1VRMS, fIN = 1.0MHz,
RL = 50Ω, Figure 1
-50
dB
Channel-to-Channel Crosstalk
VCT(V)
VNO_ _ = 1VRMS, fIN = 1.0MHz,
RS = 50Ω, Figure 1
-52
dB
>150
MHz
9
pF
-3dB Bandwidth
BW
Off-Capacitance
COFF(NO)
RSOURCE = 50Ω, RL = 50Ω
fIN = 1MHz
DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Notes 8 and 12, Figure 2)
Turn-On Time
tONSD
Turn-Off Time
tOFFSD
Break-Before-Make Time
tBBM
VNO_ _ = 1.5V,
RL = 5kΩ,
CL = 35pF
TA = +25°C
VNO_ _ = 1.5V,
RL = 300Ω,
CL = 35pF
TA = +25°C
200
500
ns
TA = TMIN to TMAX
700
75
300
ns
TA = TMIN to TMAX
MAX4572/MAX4574, VNO_ _ = 1.5V,
TA = TMIN to TMAX
400
10
125
ns
DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Note 8, Figure 2)
Turn-On Time
tONSE
VNO_ _ = 1.5V, RL = 5kΩ, CL = 35pF,
TA = +25°C
8
ms
Turn-Off Time
tOFFSE
VNO_ _ or = 1.5V, RL = 300Ω, CL = 35pF,
TA = +25°C
3
ms
POWER SUPPLY
Supply Voltage Range
V+
TA = TMIN to TMAX
+2.7
Supply Current (Note 9)
I+
All logic inputs = 0 or V+,
TA = TMIN to TMAX
+5.25
V
6
10
µA
TYP
MAX
UNITS
V+
V
ELECTRICAL CHARACTERISTICS—Single +3V Supply
(V+ = 3V ±10%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
ANALOG SWITCHES
Analog Signal Range (Note 3)
On-Resistance
VNO_ _,
VCOM_
RON
On-Resistance Match
Between Channels (Note 4)
∆RON
0
ICOM_ = 4mA,
VNO_ _ =2V,
V+ = 2.7V
TA = +25°C
ICOM_ = 4mA,
VNO_ _ = 2V,
V+ = 2.7V
TA = +25°C
43
TA = TMIN to TMAX
TA = TMIN to TMAX
90
Ω
110
1
5
Ω
5
_______________________________________________________________________________________
3
MAX4571–MAX4574
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)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
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)
PARAMETER
On-Resistance
Flatness (Note 5)
SYMBOL
RFLAT
CONDITIONS
ICOM_ = 4mA;
V+ = 2.7V;
VNO_ _ = 1V, 5V, 2V
TA = +25°C
MIN
MAX
4
10
TA = TMIN to TMAX
UNITS
Ω
10
NO_ _Off-Leakage
Current (Notes 6 and 10)
VNO_ _ = 3V, 0.5V;
VCOM_ = 0.5V, 3V;
V+ = 3.6V
TA = +25°C
-0.2
INO_ _ (OFF)
TA = TMIN to TMAX
-10
COM_ Off-Leakage
Current (Notes 6 and 10)
VNO_ _ = 3V, 0.5V;
ICOM_ (OFF) VCOM_ = 0.5V, 3V;
V+ = 3.6V
TA = +25°C
-0.2
TA = TMIN to TMAX
-10
COM _ On-Leakage
Current (Notes 6 and 10)
TA = +25°C
-0.2
ICOM_ (ON)
TA = TMIN to TMAX
-10
VCOM_ = 3V, 0.5V;
VNO_ _ = 3V, 0.5V,
or floating;
V+ = 3.6V
TYP
0.01
0.2
nA
10
0.01
0.2
nA
10
0.01
0.2
nA
10
AUDIO PERFORMANCE
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
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
>150
MHz
9
pF
VIDEO PERFORMANCE
-3dB Bandwidth
BW
Off Capacitance
COFF(NO)
RSOURCE = 50Ω, RL = 50Ω, CL = 35pF
fIN = 1MHz
DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Notes 8 and 12, Figure 2)
TA = +25°C
Turn-On Time
tONSD
VNO_ _ = 1.5V,
RL = 5kΩ, CL = 35pF
Turn-Off Time
tOFFSD
TA = +25°C
VNO_ _ = 1.5V,
RL = 300Ω, CL = 35pF TA = TMIN to TMAX
Break-Before-Make Time
tBBM
300
TA = TMIN to TMAX
VNO_ _ = 1.5V, TA = TMIN to TMAX
900
1000
100
300
400
10
ns
ns
200
ns
DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Notes 8 and 12, Figure 2)
Turn-On Time
tONSE
VNO_ _ = 1.5V, RL = 5kΩ, CL = 35pF,
TA = +25°C
8
ms
Turn-Off Time
tOFFSE
VNO_ _ = 1.5V, RL = 300Ω, CL = 35pF,
TA = +25°C
3
ms
4
_______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DIGITAL INPUTS (SCLK, DIN, CS, SCL, SDA, A0, A1)
Input Low Voltage
VIL
Input High Voltage
VIH
Input Hysteresis
VHYST
Input Leakage Current
ILEAK
Input Capacitance
V+ = 5V
0.8
V+ = 3V
0.6
V+ = 5V
3
V+ = 3V
2
Digital inputs = 0 or V+
-1
V
0.2
CIN
V
0.01
V
1
5
µA
pF
DIGITAL OUTPUTS (DOUT, SDA)
Output Low Voltage
VOL
ISINK = 6mA
DOUT Output High Voltage
VOH
ISOURCE = 0.5mA
0.4
V+
- 0.5
V
V
2-WIRE INTERFACE TIMING (Figure 3)
SCL Clock Frequency
fSCL
DC
Bus Free Time between Stop
and Start Condition
400
kHz
tBUF
1.3
µs
START Condition Hold Time
tHD:STA
0.6
µs
STOP Condition Setup Time
tSU:STO
0.6
Data Hold Time
tHD:DAT
0
Data Setup Time
tSU:DAT
100
ns
Clock Low Period
tLOW
1.3
µs
Clock High Period
tHIGH
0.6
µs
µs
0.9
µs
SCL/SDA Rise Time
tR
(Note 11)
20 +
0.1Cb
300
ns
SCL/SDA Fall Time
tF
(Note 11)
20 +
0.1Cb
300
ns
fOP
DC
2.1
MHz
DIN to SCLK Setup
tDS
100
DIN to SCLK Hold
tDH
SCLK Fall to Output Data Valid
tDO
3-WIRE TIMING (Figure 5)
Operating Frequency
CLOAD = 50pF
20
ns
0
ns
200
ns
CS to SCLK Rise Setup
tCSS
100
ns
CS to SCLK Rise Hold
tCSH
0
ns
CS High Pulse Width
tCSW
200
ns
SCLK Pulse Width Low
tCL
200
ns
SCLK Pulse Width High
tCH
200
ns
Rise Time (SCLK, DIN, CS)
tR
2
µs
Fall Time (SCLK, DIN, CS)
tF
2
µs
_______________________________________________________________________________________
5
MAX4571–MAX4574
I/O INTERFACE CHARACTERISTICS
(V+ = +2.7V to +5.25V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
Guaranteed by design. Not subject to production testing.
∆RON = RON(MAX) - RON(MIN).
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. Turnoff time is defined at the output of the switch for a 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% 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.
Note 2:
Note 3:
Note 4:
Note 5:
Typical Operating Characteristics
(V+ = +5V, TA = +25°C, unless otherwise noted.)
ON-RESISTANCE vs.
VCOM AND TEMPERATURE
30
35
V+ = 3.3V
30
TA = +70°C
26
TA = +25°C
24
10
CURRENT (nA)
40
TA = +85°C
28
100
MAX4571-4 toc02
V+ = 2.7V
ON-RESISTANCE (Ω)
1
COM_ OFF
0.1
NO_ _ OFF
22
0.01
25
TA = -40°C
20
V+ = 5.0V
NO_ _ ON
18
20
0
1
2
3
4
0.001
0
5
1
2
3
4
5
-40
-20
0
20
40
60
VCOM (V)
VCOM (V)
TEMPERATURE (°C)
SUPPLY CURRENT vs. TEMPERATURE
CHARGE INJECTION vs. VCOM
ON/OFF TIME vs. TEMPERATURE
(HARD MODE)
5.0
2
4.9
600
500
TIME (ns)
Q (pC)
4.7
tON, V+ = 3V
400
1
4.8
0
80
MAX4571-4 toc06
3
MAX4571-4 toc04
5.1
MAX4571-4 toc05
ON-RESISTANCE (Ω)
45
LEAKAGE CURRENT vs. TEMPERATURE
32
MAX4571-4 toc01
50
MAX4571-4 toc03
ON-RESISTANCE vs. VCOM
CURRENT (µA)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
tON, V+ = 5V
300
200
-1
tOFF, V+ = 3V
4.6
-2
100
4.5
-3
0
tOFF, V+ = 5V
-40
-20
0
20
40
TEMPERATURE (°C)
6
60
80
0
1
2
3
VCOM (V)
4
5
-40
-20
0
20
40
TEMPERATURE (°C)
_______________________________________________________________________________________
60
80
Serially Controlled, Clickless
Audio/Video Switches
VIDEO FREQUENCY RESPONSE
AUDIO FREQUENCY RESPONSE
600Ω IN AND OUT
-20
0
MAX4571-4 toc08
0
MAX4571-4 toc07
600Ω IN AND OUT
SIGNAL = 1VRMS
INSERTION-LOSS
-20
0.1
LOSS (dB)
LOSS (dB)
-40
-60
OFF-ISOLATION
-40
CROSSTALK
-60
-80
CROSSTALK
-80
-100
0.01
1000
10,000
100,000
10
FREQUENCY (Hz)
100
1000
10,000
0.1
100,000
10
100
ON/OFF TIMES
(HARD MODE)
MAX4571-4 toc10
CS
5V/div
1
FREQUENCY (MHz)
FREQUENCY (Hz)
ON/OFF TIMES
(SOFT MODE)
CS
5V/div
tON
tON
1V/div
1V/div
tOFF
1V/div
tOFF
TIME (2ms/div)
TIME (50ns/div)
SOFT MODE RISE TIME
SOFT MODE FALL TIME
MAX4571-4 toc12
1V/div
50Ω IN AND OUT
-100
-120
MAX4571-4 toc13
100
OFF-ISOLATION
AMPLITUDE (500mV/div)
MAX4571-4 toc11
10
AMPLITUDE (500mV/div)
THD + N (%)
1
MAX4571-4 toc09
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
TIME (500µs/div)
TIME (500µs/div)
_______________________________________________________________________________________
7
MAX4571–MAX4574
Typical Operating Characteristics (continued)
(V+ = 5V,TA = +25°C, unless otherwise noted.)
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
Pin Descriptions
PIN
NAME
FUNCTION
MAX4571
MAX4572
MAX4571
MAX4572
1, 3, 5, 7, 9,
11, 13, 22, 20,
18, 16
–
NO1–NO11
–
Normally Open Terminals
–
1, 4, 7, 10
–
NO1A–NO4A
Normally Open Terminals
–
3, 6, 9, 12
–
NO1B–NO4B
Normally Open Terminals
–
13, 16
–
NO5, NO8
Normally Open Terminals
–
22, 19, 20, 17
–
NO6A, NO7A,
NO6B, NO7B
Normally Open Terminals
2, 4, 6, 8, 10,
12, 14, 21, 19,
17, 15
2, 5, 8, 11, 14,
21, 18, 15
COM1–COM11
COM1–COM8
Common Terminals
23
23
GND
GND
24
24
A0
A0
LSB + 1 of 2-Wire Serial Interface Address Field
25
25
A1
A1
LSB + 2 of 2-Wire Serial Interface Address Field
26
26
SCL
SCL
Clock Input of 2-Wire Serial Interface
27
27
SDA
SDA
Data Input of 2-Wire Serial Interface
28
28
V+
V+
MAX4573
MAX4574
MAX4573
MAX4574
1, 3, 5, 7, 9,
11, 13, 22, 20,
18, 16
–
NO1–NO11
–
Normally Open Terminals
–
1, 4, 7, 10
–
NO1A–NO4A
Normally Open Terminals
–
3, 6, 9, 12
–
NO1B–NO4B
Normally Open Terminals
–
13, 16
–
NO5, NO8
Normally Open Terminals
–
22, 19, 20, 17
–
NO6A, NO7A,
NO6B, NO7B
Normally Open Terminals
2, 4, 6, 8, 10,
12, 14, 21, 19,
17, 15
2, 5, 8, 11, 14,
21, 18, 15
COM1–COM11
COM1–COM8
Common Terminals
23
23
GND
GND
24
24
CS
CS
Chip Select of 3-Wire Serial Interface
25
25
SCLK
SCLK
Clock Input of 3-Wire Serial Interface
26
26
DIN
DIN
Clock Input of 3-Wire Serial Interface
27
27
DOUT
DOUT
Data Output of 3-Wire Serial Interface
28
28
V+
V+
PIN
8
Ground
Positive Supply Voltage
NAME
FUNCTION
Ground
Positive Supply Voltage
_______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
MAX4571
MAX4572
MAX4573
MAX4574
V+
10nF
2/3
RL
RL
SIGNAL
GENERATOR 0dBm
NO_ _
2/3
DECODER/
CONTROLLER
COM2
NO2
GND
50Ω
NO1
COM1
ANALYZER
DECODER/
CONTROLLER
SIGNAL
GENERATOR 0dBm
MAX4571
MAX4572
MAX4573
MAX4574
V+
COM_V+
ANALYZER
V+
MAX4571–MAX4574
10nF
N.C.
GND
a) Off-Isolation
b) Crosstalk
Figure 1. Off-Isolation and Crosstalk
3V
SCL
MAX4571
MAX4572
MAX4573
MAX4574
0
VOUT
0
V+
µP
0.9 • VOUT
2-Wire
V+
NO NO_ _
2 OR 3
ACKNOWLEDGE
BIT
tr < 20ns
50%
tf < 20ns
tON
VOUT
COM_
VOUT
RL
300Ω
0
0.1 • VOUT
tOFF
CL
35pF
3V
DECODER/
CONTROLLER
CS
50%
0
SERIAL
INTERFACE
VOUT
0.9 • VOUT
GND
3-Wire
0
tON
CL INCLUDES FIXTURE AND STRAY CAPACITANCE
VOUT = VCOM [RL / (RL + RON)]
VOUT
0
0.1 • VOUT
tOFF
Figure 2. Switching Time
_______________________________________________________________________________________
9
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
Detailed Description
The MAX4571–MAX4574 are serial-interface controlled
switches with soft-mode “clickless” and hard-mode operating 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 signals. 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 softmode 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, I2Ccompatible serial interface, and the MAX4573/
MAX4574 feature a 3-wire, SPI/QSPI/MICROWIRE-compatible 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 databit 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 standard microprocessor port for communication. These
devices use the SendByte™ and WriteWord™ protocols. 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 duplicate the values present at the A0 and A1 pins of that
chip, and the rest of the address bits must be configured 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 command is executed on the rising clock edge of the
acknowledge bit after the command byte. The MODESET 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 SWITCHSET 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 master 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.
10
______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
MSB
MSB - 1
COMMAND
0
0
RESET
0
1
MODESET
1
0
NO_OP
1
1
SWITCHSET
MAX4571–MAX4574
Table 1. Command Bit Mapping
DESCRIPTION
Sets all switches open and in soft switching mode.
Sets specified switches to soft or hard mode.
No Operation.
Sets specified switches open or closed.
Table 2. Data-Bit Switch Control
DATA BIT
MAX4571/MAX4573
MAX4572/MAX4574
SWITCH
SWITCH TERMINALS
SWITCH
SWITCH TERMINALS
D13
X
X
SW8
15, 16
D12
X
X
SW5
13, 14
D11
X
X
SW7B
17, 18
D10
SW11
15, 16
SW7A
18, 19
D9
SW10
17, 18
SW6B
20, 21
D8
SW9
19, 20
SW6A
21, 22
D7
SW8
21, 22
SW4B
11, 12
D6
SW7
13, 14
SW4A
10, 11
D5
SW6
11, 12
SW3B
8, 9
D4
SW5
9, 10
SW3A
7, 8
D3
SW4
7, 8
SW2B
5, 6
D2
SW3
5, 6
SW2A
4, 5
D1
SW2
3, 4
SW1B
2, 3
D0 (LSB)
SW1
1, 2
SW1A
1, 2
X = Don’t care
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 information are clocked in on the rising edge of the serialclock 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 serial 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 associated 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-
______________________________________________________________________________________
11
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
Table 3. 2-Wire Serial-Interface Data Format
RESET Command
Address Byte
Command Byte (RESET)
MSB
S
R
T
0
LSB
1
1
0
1
A
1
A
0
0
MSB
A
C
K
LSB
0
0
X
X
X
X
X
X
A
C
K
S
T
P
SWITCHSET Command
Command Byte (SWITCHSET)
Address Byte
LSB
MSB
S
R
T
0
1
1
0
1
A
1
A
0
0
MSB
A
C
K
1
LSB
1
X
X
X
X
X
X
A
C
K
MAX4571
Second Data Byte
First Data Byte
LSB
MSB
X
X
X
X
X
SW
11
SW
10
LSB
MSB
SW
9
A
C
K
SW
8
SW
7
SW
6
SW
5
SW
4
SW
3
SW
2
SW
1
SW
1B
SW
1A
A
C
K
S
T
P
A
C
K
S
T
P
A
C
S
T
K
P
MAX4572
Second Data Byte
First Data Byte
LSB
MSB
X
X
SW
8
SW
5
SW
7B
SW
7A
SW
6B
LSB
MSB
SW
6A
A
C
K
SW
4B
SW
4A
SW
3B
SW
3A
SW
2B
SW
2A
MODESET Command
Command Byte (MODESET)
Address Byte
MSB
MSB
S
R
T
0
1
1
0
1
A
1
A
0
0
A
C
K
0
LSB
1
X
X
X
X
X
X
A
C
K
MAX4571
Second Data Byte
First Data Byte
LSB
MSB
X
X
X
X
X
SW
11
SW
10
SW
9
LSB
MSB
A
C
SW
8
SW
7
SW
6
SW
5
SW
4
SW
3
SW
2
SW
1
K
MAX4572
First Data Byte
Second Data Byte
LSB
MSB
X
X
SW
SW
SW
SW
SW
SW
A
SW
SW
SW
SW
SW
SW
SW
SW
A
S
8
5
7B
7A
6B
6A
C
K
4B
4A
3B
3A
2B
2A
1B
1A
C
K
T
P
X = Don't Care
SRT = Start Condition
ACK = Acknowledge Condition
12
LSB
MSB
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.
______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
MAX4573 (11 SPST)
MSB
LSB
COMMAND
SWITCH CONTROL
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
C1
C0
X
X
X
SW11
SW10
SW9
SW8
SW7
SW6
SW5
SW4
SW3
SW2
SW1
MAX4574 (6 SPDT + 2 SPST)
MSB
LSB
COMMAND
SWITCH CONTROL
D15
D14
D13
D12
D11
C1
C0
SW8
SW5
SW7B
70%
SDA
D10
D9
D8
SW7A SW6B SW6A
D7
70%
20%
D6
SW4B SW4A
D5
D4
D3
SW3B SW3A
D2
70%
20%
70%
20%
tSU, DAT
D1
D0
SW2B SW2A SW1B SW1A
70%
20%
20%
tBUF
tSU, STA
tHD, STA
tLOW
70%
20%
SCL
tSU, STO
tHD, DAT
70%
20%
tHIGH
tHD, STA
tR
70%
20%
70%
70%
70%
tF
START CONDITION
REPEATED START CONDITION
STOP CONDITION
START CONDITION
Figure 3. 2-Wire Serial-Interface Timing Diagram
COMMAND BYTE
ADDRESS BYTE
SECOND DATA BYTE
FIRST DATA BYTE
SDA
MSB
LSB
ACK
MSB
LSB
ACK
MSB
LSB
ACK
MSB
LSB ACK
SCL
STOP CONDITION
START CONDITION
Figure 4. A Complete 2-Wire Serial-Interface Transmission
______________________________________________________________________________________
13
MAX4571–MAX4574
Table 4. 3-Wire Serial-Interface Data Format
MAX4571–MAX4574
Serially Controlled, Clickless
Audio/Video Switches
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.
20%
CS
20%
70%
tCSW
tCSH
SCLK
20%
tDH
20%
tCSO
tCH
tCL
tCSS
70%
20% 20%
70%
70%
20%
tDS
D15
DIN
D14
D1
D0
tDO
DOUT
Figure 5. 3-Wire Serial-Interface Timing Diagram
CS
COMMAND
EXECUTED
SCLK
1
8
16
9
DIN
D15 D14 D13....
MSB
D2
D1
D0....
LSB
DOUT
Q15........
MSB FROM
PREVIOUS WRITE
.........00
LSB FROM
PREVIOUS WRITE
Figure 6. A Complete 3-Wire Serial-Interface Transmission
14
______________________________________________________________________________________
Serially Controlled, Clickless
Audio/Video Switches
___________________Chip Information
TRANSISTOR COUNT: 5397
TOP VIEW
MAX4572/MAX4574
NO1A 1
28 V+
COM1 2
27 SDA (DOUT)
NO1B 3
26 SCL (DIN)
NO2A 4
25 A1 (SCLK)
COM2 5
24 A0 (CS)
NO2B 6
23 GND
NO3A 7
22 NO6A
COM3 8
21 COM6
NO3B 9
20 NO6B
NO4A 10
19 NO7A
COM4 11
18 COM7
NO4B 12
17 NO7B
NO5 13
16 NO8
COM5 14
15 COM8
QSOP/SSOP/SO
( ) ARE FOR MAX4574
QSOP.EPS
Package Information
______________________________________________________________________________________
15
MAX4571–MAX4574
Pin Configurations (continued)
Serially Controlled, Clickless
Audio/Video Switches
SOICW.EPS
SSOP.EPS
MAX4571–MAX4574
Package Information (continued)
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.
工商网监
湘ICP备2023018690号
