MAXIM MAX4545EAP

19-1232; Rev 0; 6/97
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
____________________________Features
________________________Applications
♦ Low 50Ω Insertion Loss: -1dB at 100MHz
♦ High 50Ω Off Isolation: -80dB at 10MHz
♦ Low 50Ω Crosstalk: -80dB at 10MHz
♦ DC to 300MHz -3dB Signal Bandwidth
♦ 20Ω Signal Paths with ±5V Supplies
♦ 1Ω Signal-Path Matching with ±5V Supplies
♦ 0.5Ω Signal-Path Flatness with ±5V Supplies
♦ ±2.7V to ±6V Dual Supplies
+2.7V to +12V Single Supply
♦ Low Power Consumption: <1µW
♦ Rail-to-Rail Bidirectional Signal Handling
♦ Pin Compatible with Industry-Standard DG540,
DG542, DG643
♦ >2kV ESD Protection per Method 3015.7
♦ TTL/CMOS-Compatible Inputs
with Single +5V or ±5V
______________Ordering Information
RF Switching
Video Signal Routing
PART
High-Speed Data Acquisition
Test Equipment
TEMP. RANGE
PIN-PACKAGE
MAX4545CPP
0°C to +70°C
20 Plastic DIP
MAX4545CWP
0°C to +70°C
20 Wide SO
Ordering Information continued at end of data sheet.
ATE Equipment
Networking
_____________________Pin Configurations/Functional Diagrams/Truth Tables
TOP VIEW
IN1 1
19 COM2
GND1 3
18 GND2
N01 4
17 NO2
V- 5
16 V+
MAX4545
GND5 6
15 GND6
N04 7
14 N03
GND4 8
13 GND3
COM4 9
12 COM3
IN4 10
SWITCHES SHOWN
FOR LOGIC “0” INPUT
MAX4546
20 IN2
COM1 2
11 IN3
MAX4547
16 IN2
IN1 1
16 N02
COM1 2
15 COM2
N01 2
15 V+
GND1 3
14 GND2
V- 3
14 GND2
13 NO2
GND1 4
13 COM2
12 V+
COM1 5
12 GND3
GND4 6
11 V-
IN1 1
N01 4
V- 5
NC4 6
11 NC3
GND4 7
10 GND3
V+ 7
COM4 8
9 COM3
NC1 8
10 NC2
9 IN2
DIP/SO/SSOP
DIP/SO/QSOP
MAX4545
LOGIC
SWITCH
LOGIC
MAX4546
1, 2
3, 4
LOGIC
NO-COM
NC-COM
0
1
OFF
ON
ON
OFF
0
1
OFF
ON
ON
OFF
0
1
OFF
ON
DIP/SO/QSOP
MAX4547
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX4545/MAX4546/MAX4547
_______________General Description
The MAX4545/MAX4546/MAX4547 are low-voltage
T-switches designed for switching RF and video signals
from DC to 300MHz in 50Ω and 75Ω systems. The
MAX4545 contains four normally open single-pole/singlethrow (SPST) switches. The MAX4546 contains two dual
SPST switches (one normally open, one normally closed.)
The MAX4547 contains two single-pole/double-throw
(SPDT) switches.
Each switch is constructed in a “T” configuration, ensuring
excellent high-frequency off isolation and crosstalk of
-80dB at 10MHz. They can handle Rail-to-Rail® analog signals in either direction. On-resistance (20Ω max) is
matched between switches to 1Ω max and is flat (0.5Ω
max) over the specified signal range, using ±5V supplies.
The off leakage current is less than 5nA at +25°C and
50nA at +85°C.
These CMOS switches can operate with dual power supplies ranging from ±2.7V to ±6V or a single supply
between +2.7V and +12V. All digital inputs have 0.8V/2.4V
logic thresholds, ensuring both TTL- and CMOS-logic compatibility when using ±5V or a single +5V supply.
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND)
V+ ...........................................................................-0.3V, +13.0V
V- ............................................................................-13.0V, +0.3V
V+ to V-...................................................................-0.3V, +13.0V
All Other Pins (Note 1) ..........................(V- - 0.3V) to (V+ + 0.3V)
Continuous Current into Any Terminal..............................±25mA
Peak Current into Any Terminal
(pulsed at 1ms, 10% duty cycle)..................................±50mA
ESD per Method 3015.7 ..................................................>2000V
Continuous Power Dissipation (TA = +70°C) (Note 2)
16-Pin Plastic DIP
(derate 10.53mW/°C above +70°C) ..........................842mW
16-Pin Narrow SO
(derate 8.70mW/°C above +70°C) ............................696mW
16-Pin QSOP (derate 8.3mW/°C above +70°C).......... 667mW
20-Pin Plastic DIP (derate 8.0mW/°C above +70°C) ...640mW
20-Pin Wide SO (derate 10.00mW/°C above +70°C) .. 800mW
20-Pin SSOP (derate 8.0mW/°C above +70°C) .......... 640mW
Operating Temperature Ranges
MAX454_C_ E .....................................................0°C to +70°C
MAX454_E_ E ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1: Voltages on all other pins 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—Dual Supplies
(V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, VINL = 0.8V, VINH = 2.4V, VGND_ = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
TYP
(Note 2)
MAX
UNITS
ANALOG SWITCH
Analog Signal Range
Signal-Path On-Resistance
Signal-Path On-Resistance Match
Between Channels (Note 4)
VCOM_,
VNO_,VNC_
(Note 3)
C, E
V-
V+
V
Ω
RON
V+ = 4.5V, V- = -4.5V,
VCOM_ = ±2V, ICOM_ = 10mA
+25°C
14
20
C, E
18
25
∆RON
V+ = 4.5V, V- = -4.5V,
VCOM_ = ±2V, ICOM_ = 10mA
+25°C
0.5
C, E
1
1.25
Signal-Path On-Resistance
Flatness (Note 5)
RFLAT(ON)
V+ = 5V; V- = -5V; VCOM_ = 1V,
0V, -1V; ICOM = 10mA
NO_, NC_ Off Leakage Current
(Note 6)
INO_(OFF),
INC_(OFF)
V+ = 5.5V, V- = -5.5V,
±
VCOM_ = ±4.5V, VN_ = 4.5V
+25°C
-5
C, E
-50
COM_ Off Leakage Current
(Note 6)
ICOM_(OFF)
V+ = 5.5V, V- = -5.5V,
VCOM_ = ±4.5V, VN_ = ±4.5V
+25°C
-5
C, E
-50
COM_ On Leakage Current
(Note 6)
ICOM_(ON)
V+ = 5.5V, V- = -5.5V,
±
VCOM_ = ±4.5V, VN_ = 4.5V
+25°C
-10
C, E
-100
+25°C
0.3
0.02
0.5
5
50
0.02
5
50
0.04
10
100
Ω
Ω
nA
nA
nA
LOGIC INPUT
IN_ Input Logic Threshold High
VIN_H
C, E
IN_ Input Logic Threshold Low
VIN_L
C, E
0.8
1.5
IN_ Input Current Logic High or
Low
IINH_, IINL_
C, E
-1
0.03
2
VIN_ = 0.8V or 2.4V
1.5
_______________________________________________________________________________________
2.4
V
V
1
µA
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
(V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, VINL = 0.8V, VINH = 2.4V, VGND_ = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
TYP
(Note 2)
MAX
90
150
UNITS
SWITCH DYNAMIC CHARACTERISTICS
Turn-On Time
tON
VCOM_ = ±3V, V+ = 5V, V- = -5V,
Figure 4
+25°C
Turn-Off Time
tOFF
VCOM_ = ±3V, V+ = 5V, V- = -5V,
Figure 4
+25°C
Break-Before-Make Time Delay
(MAX4546/MAX4547 only)
tBBM
VCOM_ = ±3V, V+ = 5V, V- = -5V,
Figure 5 (Note 3)
+25°C
Q
CL = 1.0nF, VNO_ = 0V, RS = 0Ω,
Figure 6
+25°C
60
CN_(OFF)
VNO_ = GND, f = 1MHz, Figure 8
+25°C
6
Charge Injection
(Note 3)
NO_, NC_ Off Capacitance
COM_ Off Capacitance
COM_ On Capacitance
Off Isolation (Note 7)
Channel-to-Channel Crosstalk
(Note 8)
-3dB Bandwidth
VCOM_ = 0V,
CCOM_(OFF) f = 1MHz,
Figure 8
CCOM_(ON)
VISO
VCT
BW
Distortion
THD+N
C, E
200
35
C, E
100
120
15
MAX4545
40
150
MAX4545
RL = 50Ω, VCOM_ =
1VRMS, f = 10MHz,
Figure 7
MAX4545
MAX4546
pF
pF
6
11.5
+25°C
11.5
pF
17
-80
+25°C
-80
MAX4547
MAX4546
pC
6
MAX4546
RL = 50Ω,
VCOM_ = 1VRMS,
f = 10MHz, Figure 7
ns
ns
+25°C
MAX4545
VCOM_ = VNO_ = 0V,
MAX4546
f = 1MHz, Figure 8
MAX4547
ns
dB
-82
-88
+25°C
-80
MAX4547
dB
-84
Figure 7, RL = 50Ω
+25°C
300
MHz
VIN = 5Vp-p, f < 20kHz,
600Ω in and out
+25°C
0.004
%
POWER SUPPLY
Power-Supply Range
V+, V-
C, E
V+ Supply Current
I+
V+ = 5.5V, all VIN_ = 0V or V+
V - Supply Current
I-
V- = -5.5V
-6
+25°C
-1
C, E
-10
+25°C
-1
C, E
-10
+6
0.05
1
10
0.05
1
10
V
µA
µA
_______________________________________________________________________________________
3
MAX4545/MAX4546/MAX4547
ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
ELECTRICAL CHARACTERISTICS—Single +5V Supply
(V+ = +4.5V to +5.5V, V- = 0V, VINL = 0.8V, VINH = 2.4V, VGND_ = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are
at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
TYP
(Note 2)
MAX
UNITS
ANALOG SWITCH
Analog Signal Range
VCOM_,
VNO_, VNC_
(Note 3)
+25°C
0
26
V+
V
40
Ω
Signal-Path On-Resistance
RON
V+ = 4.5V, VCOM_ = 3.5V,
ICOM_ = 1mA
+25°C
C, E
60
Signal-Path On-Resistance
Match
∆RON
V+ = 4.5V, VCOM_ = 3.5V,
ICOM_ = 1mA
+25°C
2
C, E
4
NO_, NC_ Off Leakage Current
(Note 9)
INO_(OFF),
INC_(OFF)
V+ = 5.5V, VCOM_ = 1V,
VN_ = 4.5V
+25°C
-5
C, E
-50
COM_ Off Leakage Current
(Note 9)
ICOM_(OFF)
V+ = 5.5V, VCOM_ = 1V,
VN_ = 4.5V
+25°C
-5
C, E
-50
COM_ On Leakage Current
(Note 9)
ICOM_(ON)
V+ = 5.5V; VCOM_ = 1V, 4.5V
+25°C
-10
C, E
-100
0.02
5
50
0.02
5
50
0.04
10
100
Ω
nA
nA
nA
LOGIC INPUT
IN_ Input Logic Threshold High
VIN_H
C, E
IN_ Input Logic Threshold Low
VIN_L
C, E
0.8
1.5
IN_ Input Current Logic High or
Low
IINH_, IINL_
C, E
-1
0.03
1
130
250
VIN_ = 0.8V or 2.4V
1.5
2.4
V
V
µA
SWITCH DYNAMIC CHARACTERISTICS
Turn-On Time
tON
VCOM_ = 3V, V+ = 5V,
Figure 4
+25°C
Turn-Off Time
tOFF
VCOM_ = 3V, V+ = 5V,
Figure 4
+25°C
Break-Before-Make Time Delay
(MAX4546/MAX4547 only)
tBBM
VCOM_ = 3V, V+ = 5V,
Figure 5 (Note 3)
+25°C
CL = 1.0nF, VNO = 2.5V,
RS = 0Ω, Figure 6
Charge Injection
Q
C, E
350
40
C, E
100
150
20
ns
ns
70
ns
+25°C
25
pC
Off-Isolation
(Note 7)
VISO
RL = 50Ω, VCOM_ = 1VRMS,
f = 10MHz, Figure 7
+25°C
-75
dB
Channel-to-Channel Crosstalk
(Note 8)
VCT
RL = 50Ω, VCOM_ = 1VRMS,
f = 10MHz, Figure 7
+25°C
-70
dB
POWER SUPPLY
V+ Supply Current
4
I+
V+ = 5.5V, all VIN_ = 0V or V+
+25°C
-1
C, E
-10
0.05
_______________________________________________________________________________________
1
10
µA
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
(V+ = +2.7V to +3.6V, V- = 0V, VINL = 0.8V, VINH = 2.4V, VGND_ = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are
at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
TYP
(Note 2)
MAX
UNITS
ANALOG SWITCH
Analog Signal Range
VCOM_,
VNO_, VNC_
(Note 3)
+25°C
RON
V+ = 2.7V, VCOM_ = 1V,
ICOM_ = 1mA
+25°C
IN_ Input Logic Threshold High
VIN_H
(Note 3)
C, E
IN_ Input Logic Threshold Low
VIN_L
(Note 3)
C, E
0.8
IN_ Input Current Logic High or
Low
IINH_, IINL_
VIN_ = 0.8V or 2.4V (Note 3)
C, E
-1
Signal-Path On-Resistance
0
70
C, E
V+
V
120
Ω
150
LOGIC INPUT
1.0
2.4
1.0
V
V
1
µA
SWITCH DYNAMIC CHARACTERISTICS
Turn-On Time
tON
VCOM_ = 1.5V, V+ = 2.7V,
Figure 4 (Note 3)
+25°C
Turn-Off Time
tOFF
VCOM_ = 1.5V, V+ = 2.7V,
Figure 4 (Note 3)
+25°C
Break-Before-Make Time Delay
(MAX4546/MAX4547 only)
tBBM
VCOM_ = 1.5V, V+ = 2.7V,
Figure 5 (Note 3)
300
C, E
600
800
50
C, E
150
200
+25°C
15
100
+25°C
-1
0.05
C, E
-10
ns
ns
ns
POWER SUPPLY
V+ Supply Current
V+ Supply Current
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
I+
V+ = 3.6V, all VIN_ = 0V or V+
1
10
µA
The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
Guaranteed by design.
∆RON = ∆RON(MAX) - ∆RON(MIN).
Resistance flatness is defined as the difference between the maximum and the minimum value of on-resistance as measured over the specified analog signal range.
Leakage parameters are 100% tested at the maximum rated hot temperature and guaranteed by correlation at +25°C.
Off isolation = 20log10 [VCOM / (VNC or VNO)], VCOM = output, VNC or VNO = input to off switch.
Between any two switches.
Leakage testing for single-supply operation is guaranteed by testing with dual supplies.
_______________________________________________________________________________________
5
MAX4545/MAX4546/MAX4547
ELECTRICAL CHARACTERISTICS—Single +3V Supply
__________________________________________Typical Operating Characteristics
(V+ = +5V, V- = -5V, TA = +25°C, GND = 0V, packages are surface mount, unless otherwise noted.)
ON-RESISTANCE vs. VCOM
AND TEMPERATURE
(DUAL SUPPLIES)
ON-RESISTANCE vs. VCOM
(SINGLE SUPPLY)
V+, V- = 1.2V, -1.2V
25
MAX4545 TOC02
1000
MAX4545 TOC01
100
V- = 0V
23
TA = +125°C
21
V+ = 2.7V
100
V+ = 3.3V
2
3
4
0
5
1
2
3
4
5
6
7
8
9
VCOM (V)
ON-RESISTANCE vs. VCOM
AND TEMPERATURE
(SINGLE SUPPLY)
ON/OFF-LEAKAGE CURRENT vs.
TEMPERATURE
-3
-2
-1
1
LEAKAGE (nA)
TA = +25°C
25
2
ON/OFF LEAKAGE
0.1
0.01
0.0001
-50
-25
0
25
50
VCOM (V)
TEMPERATURE (°C)
ON/OFF TIME vs.
SUPPLY VOLTAGE
ON/OFF TIME vs.
TEMPERATURE
100 125
-4
-3
-2
-1
0
1
2
POWER-SUPPLY CURRENT
vs. TEMPERATURE
1
tON
0.1
I+
tON
70
I+, I- (µA)
tON, tOFF (ns)
80
150
60
50
40
50
V+, V- (V)
I0.001
0.0001
0.00001
10
±6
0.01
20
0
6
tOFF
30
tOFF
3
VCOM (V)
100
90
-5
MAX4545 TOC08
200
75
110
MAX4545 TOC07
250
±5
5
-20
-75
MAX4545 TOC09
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
±4
4
SINGLE
SUPPLY
0
10
±3
5
40
20
TA = -55°C
±2
4
DUAL
SUPPLIES
60
0.001
100
3
100
TA = 0°C
0
1
CHARGE INJECTION vs. VCOM
Qj (pC)
30
15
0
80
TA = +85°C
20
-4
120
MAX4545 TOC05
TA = +125°C
35
10
MAX4545 TOC04
40
-5
10
VCOM (V)
VCOM (V)
45
RON (Ω)
5
10
1
TA = -55°C
7
V+ = 10V
10
0
TA = 0°C
9
V+, V- = 5V, -5V
-1
TA = +25°C
11
V+ = 7.5V
V+, V- = 3.3V, -3.3V
-4 -3 -2
15
13
V+ = 5V
-5
TA = +85°C
17
MAX4545 TOC06
V+, V- =
2.7V, -2.7V
RON (Ω)
V+ = 2V
RON (Ω)
RON (Ω)
19
V+, V- = 2V, -2V
MAX4545 TOC03
ON-RESISTANCE vs. VCOM
(DUAL SUPPLIES)
tON, tOFF (ns)
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
±8
-75
-50 -25
0
25
50
TEMPERATURE (°C)
75 100 125
-75
-50 -25
0
25
50
TEMPERATURE (°C)
_______________________________________________________________________________________
75 100 125
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
1.2
LOSS (dB)
1.0
0.8
0.6
INSERTION LOSS
-50
-60
-70
0.2
OFF ISOLATION
-40
-50
OFF ISOLATION
-60
-80
CROSSTALK
-90
-100
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
0.1
1
V+ (V)
10
100
1
1000
10
100
100
80
V+ = +5V
V- = -5V
5Vp-p SIGNAL
600Ω SOURCE AND LOAD
40
-30
20
ON PHASE
0
-50
-20
-60
-40
-70
OFF ISOLATION
-80
-60
-100
-100
1
10
100
FREQUENCY (MHz)
1
0.1
0.01
0.001
-80
CROSSTALK
-90
10
THD (%)
60
-20
ON PHASE (DEGREES)
-10
MAX14545 TOC14
MAX4545 TOC13
ON LOSS
-40
1000
MAX4547
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
FREQUENCY RESPONSE
0
100
FREQUENCY (MHz)
FREQUENCY (MHz)
10
SWITCH LOSS (dB)
0
INSERTION
LOSS
-70
CROSSTALK
-110
-120
0
V+ = +5V
V- = -5V
5VΩ INPUT
50 Ω OUTPUT
-20
-30
-80
-90
-100
0.4
0
-10
LOSS (dB)
1.4
V+ = +5V
V- = -5V
5VΩ INPUT
50Ω OUTPUT
-10
-20
-30
-40
MAX14545 TOC11
0
MAX4545 TOC10
1.6
LOGIC-LEVEL THRESHOLD (V)
MAX4546
FREQUENCY RESPONSE
MAX4545
FREQUENCY RESPONSE
MAX4545 TOC12
LOGIC-LEVEL THRESHOLD
vs. POSITIVE SUPPLY VOLTAGE
1000
0.0001
10
100
1k
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
7
MAX4545/MAX4546/MAX4547
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, TA = +25°C, GND = 0V, packages are surface mount, unless otherwise noted.)
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
______________________________________________________________Pin Description
PIN
NAME
FUNCTION*
MAX4545
MAX4546
MAX4547
1, 10, 11,
20
1, 16
1, 9
IN_
3, 6, 8, 13,
15, 18
3, 7, 10, 14
4, 6, 12, 14
GND_
16
12
7, 15
V+
Positive Supply-Voltage Input (analog and digital)
5
5
3, 11
V-
Negative Supply-Voltage Input. Connect to ground plane for single-supply
operation.
4, 7, 14, 17
4, 13
2, 16
NO_
Analog Switch Normally Open** Terminals
—
6, 11
8, 10
NC_
Analog Switch Normally Closed** Terminals
2, 9, 12, 19
2, 8, 9, 15
5, 13
COM_
Digital Control Input
RF and Logic Ground. Grounds are not internally connected to each other,
and should all be connected to a ground plane (see Grounding section).
Analog Switch Common** Terminals
* All pins have ESD diodes to V- and V+.
** NO_ (or NC_) and COM_ pins are identical and interchangeable. Either may be considered as an input or output; signals pass
equally well in either direction.
_______________Theory of Operation
Logic-Level Translators
The MAX4545/MAX4546/MAX4547 are constructed as
high-frequency “T” switches, as shown in Figure 1. The
logic-level input, IN_, is translated by amplifier A1 into a
V+ to V- logic signal that drives amplifier A2. (Amplifier
A2 is an inverter for normally closed switches.)
Amplifier A2 drives the gates of N-channel MOSFETs
N1 and N2 from V+ to V-, turning them fully on or off.
The same signal drives inverter A3 (which drives the
P-channel MOSFETs P1 and P2) from V+ to V-, turning
them fully on or off, and drives the N-channel MOSFET
N3 off and on.
The logic-level threshold is determined by V+ and
GND_. The voltage on GND_ is usually at ground
potential, but it may be set to any voltage between
(V+ - 2V) and V-. When the voltage between V+ and
GND_ is less than 2V, the level translators become very
slow and unreliable. Since individual switches in each
package have individual GND_ pins, they may be set to
different voltages. Normally, however, they should all
be connected to the ground plane.
Switch On Condition
When the switch is on, MOSFETs N1, N2, P1, and P2
are on and MOSFET N3 is off. The signal path is COM_
to NO_, and because both N-channel and P-channel
MOSFETs act as pure resistances, it is symmetrical
8
NORMALLY OPEN SWITCH CONSTRUCTION
N1
COM_
D
IN_
COM_ - NO_
0
1
OFF
ON
N2
S
D
P1
P2
D
S
NO_
S
S
D
V+
A1
A2
D
A3
IN_
N3
S
GND_
V+
VA1
(NC)
BSD DIODES
ON GND_, IN_,
COM_, NO_, AND NC_
V+
Figure 1. T-Switch Construction
(i.e., signals may pass in either direction). The off
MOSFET, N3, has no DC conduction, but has a small
amount of capacitance to GND_. The four on
MOSFETs also have capacitance to ground that,
together with the series resistance, forms a lowpass filter. All of these capacitances are distributed evenly
along the series resistance, so they act as a transmission line rather than a simple R-C filter. This helps to
explain the exceptional 300MHz bandwidth when the
switches are on.
_______________________________________________________________________________________
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
The MAX4545/MAX4546/MAX4547 are optimized for
±5V operation. Using lower supply voltages or a single
supply increases switching time, increases on-resistance (and therefore on-state attenuation), and increases nonlinearity.
Switch Off Condition
When the switch is off, MOSFETs N1, N2, P1, and P2
are off and MOSFET N3 is on. The signal path is
through the off-capacitances of the series MOSFETs,
but it is shunted to ground by N3. This forms a highpass filter whose exact characteristics are dependent
on the source and load impedances. In 50Ω systems,
and below 10MHz, the attenuation can exceed 80dB.
This value decreases with increasing frequency and
increasing circuit impedances. External capacitance
and board layout have a major role in determining overall performance.
__________Applications Information
Power-Supply Considerations
Overview
The MAX4545/MAX4546/MAX4547 construction is typical of most CMOS analog switches. It has three supply
pins: V+, V-, and GND. V+ and V- are used to drive the
internal CMOS switches and set the limits of the analog
voltage on any switch. Reverse ESD protection diodes
are internally connected between each analog signal
pin and both V+ and V-. If the voltage on any pin
exceeds V+ or V-, one of these diodes will conduct.
During normal operation these reverse-biased ESD
diodes leak, forming the only current drawn from V-.
Virtually all the analog leakage current is through the
ESD diodes. Although the ESD diodes on a given signal pin are identical, and therefore fairly well balanced,
they are reverse biased differently. Each is biased by
either V+ or V- and the analog signal. This means their
leakages vary as the signal varies. The difference in the
two diode leakages from the signal path to the V+ and
V- pins constitutes the analog signal-path leakage current. All analog leakage current flows to the supply terminals, not to the other switch terminal. This explains
how both sides of a given switch can show leakage
currents of either the same or opposite polarity.
There is no connection between the analog signal
paths and GND. The analog signal paths consist of an
N-channel and P-channel MOSFET with their sources
and drains paralleled and their gates driven out of
phase with V+ and V- by the logic-level translators.
V+ and GND power the internal logic and logic-level
translators, and set the input logic thresholds. The
logic-level translators convert the logic levels to
switched V+ and V- signals to drive the gates of the
analog switches. This drive signal is the only connection between the logic supplies and the analog supplies. All pins have ESD protection to V+ and to V-.
Increasing V- has no effect on the logic-level thresholds, but it does increase the drive to the P-channel
switches, reducing their on-resistance. V- also sets the
negative limit of the analog signal voltage.
The logic-level thresholds are CMOS and TTL compatible when V+ is +5V. As V+ is raised, the threshold
increases slightly; when V+ reaches +12V, the level
threshold is about 3.1V, which is above the TTL output
high-level minimum of 2.8V, but still compatible with
CMOS outputs.
Bipolar-Supply Operation
The MAX4545/MAX4546/MAX4547 operate with bipolar
supplies between ±2.7V and ±6V. The V+ and V- supplies need not be symmetrical, but their sum cannot
exceed the absolute maximum rating of 13.0V. Do not
connect the MAX4545/MAX4546/MAX4547 V+ pin to
+3V and connect the logic-level input pins to TTL
logic-level signals. TTL logic-level outputs can
exceed the absolute maximum ratings, causing
damage to the part and/or external circuits.
CAUTION:
The absolute maximum V+ to V- differential
voltage is 13.0V. Typical “±6-Volt” or “12-Volt”
supplies with ±10% tolerances can be as high
as 13.2V. This voltage can damage the
MAX4545/MAX4546/MAX4547. Even ±5% tolerance supplies may have overshoot or noise
spikes that exceed 13.0V.
Single-Supply Operation
The MAX4545/MAX4546/MAX4547 operate from a single supply between +2.7V and +12V when V- is connected to GND. All of the bipolar precautions must be
observed. Note, however, that these parts are optimized for ±5V operation, and most AC and DC characteristics are degraded significantly when departing
from ±5V. As the overall supply voltage (V+ to V-) is
lowered, switching speed, on-resistance, off isolation,
and distortion are degraded. (See Typical Operating
Characteristics.)
_______________________________________________________________________________________
9
MAX4545/MAX4546/MAX4547
Typical attenuation in 50Ω systems is -1dB and is reasonably flat up to 100MHz. Higher-impedance circuits
show even lower attenuation (and vice versa), but
slightly lower bandwidth due to the increased effect of
the internal and external capacitance and the switch’s
internal resistance.
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
Single-supply operation also limits signal levels and
interferes with grounded signals. When V- = 0V, AC signals are limited to -0.3V. Voltages below -0.3V can be
clipped by the internal ESD-protection diodes, and the
parts can be damaged if excessive current flows.
Power Off
When power to the MAX4545/MAX4546/MAX4547 is off
(i.e., V+ = 0V and V- = 0V), the Absolute Maximum
Ratings still apply. This means that neither logic-level
inputs on IN_ nor signals on COM_, NO_, or NC_ can
exceed ±0.3V. Voltages beyond ±0.3V cause the internal ESD-protection diodes to conduct, and the parts
can be damaged if excessive current flows.
Grounding
DC Ground Considerations
Satisfactory high-frequency operation requires that
careful consideration be given to grounding. For most
applications, a ground plane is strongly recommended, and all GND_ pins should be connected to
it with solid copper. While the V+ and V- power-supply
pins are common to all switches in a given package,
each switch has separate ground pins that are not
internally connected to each other. This contributes to
the overall high-frequency performance and provides
added flexibility in some applications, but it can cause
problems if it is overlooked. All the GND_ pins have
ESD diodes to V+ and V-.
In systems that have separate digital and analog (signal) grounds, connect these switch GND_ pins to analog ground. Preserving a good signal ground is much
more important than preserving a digital ground.
Ground current is only a few nanoamps.
The logic-level inputs, IN_, have voltage thresholds
determined by V+ and GND_. (V- does not influence
the logic-level threshold.) With +5V and 0V applied to
V+ and GND_, the threshold is about 1.6V, ensuring
compatibility with TTL- and CMOS-logic drivers.
The various GND_ pins can be connected to separate
voltage potentials if any or all of the logic-level inputs is
not a normal logic signal. (The GND_ voltages cannot
exceed (V+ - 2V) or V-.) Elevating GND_ reduces off
isolation. For example, using the MAX4545, if GND2–
GND6 are connected to 0V and GND1 is connected to
V-, then switches 2, 3, and 4 would be TTL/CMOS compatible, but switch 1 (IN1) could be driven with the railto-rail output of an op amp operating from V+ and V-.
Note, however, that IN_ can be driven more negative
than GND_, as far as V-. GND_ does not have to be
removed from 0V when IN_ is driven from bipolar
sources, but the voltage on IN_ should never exceed V-.
10
GND_ should be separated from 0V only if the logiclevel threshold has to be changed.
Any GND_ pin not connected to 0V should be
bypassed to the ground plane with a surface-mount
10nF capacitor to maintain good RF grounding. DC
current in the IN_ and GND_ pins is less than 1nA, but
increases with switching frequency.
On the MAX4545 only, two extra ground pins—GND5
and GND6—are provided to improve isolation and
crosstalk. They are not connected to the logic-level circuit. These pins should always be connected to the
ground plane with solid copper.
AC Ground and Bypassing
A ground plane is mandatory for satisfactory highfrequency operation. (Prototyping using hand wiring or
wire-wrap boards is strongly discouraged.) Connect all
0V GND_ pins to the ground plane with solid copper.
(The GND_ pins extend the high-frequency ground
through the package wire-frame, into the silicon itself,
thus improving isolation.) The ground plane should be
solid metal underneath the device, without interruptions.
There should be no traces under the device itself. For
DIP packages, this applies to both sides of a two-sided
board. Failure to observe this will have a minimal effect
on the “on” characteristics of the switch at high frequencies, but it will degrade the off isolation and crosstalk.
All V+ and V- pins should be bypassed to the ground
plane with surface-mount 10nF capacitors. For DIP
packages, they should be mounted as close as possible to the pins on the same side of the board as the
device. Do not use feedthroughs or vias for bypass
capacitors. For surface-mount packages, the pins are
so close to each other that the bypass capacitors
should be mounted on the opposite side of the board
from the device. In this case, use short feedthroughs or
vias, directly under the V+ and V- pins. Any GND_ pin
not connected to 0V should be similarly bypassed. If Vis 0V, connect it directly to the ground plane with solid
copper. Keep all leads short.
The MAX4547 has two V+ and V- pins. Make DC connections to only one of each to minimize crosstalk. Do
not route DC current into one of the V+ or V- pins and
out the other V+ or V- pin to other devices. The second
set of V+ and V- pins is for AC bypassing only.
For dual-supply operation, the MAX4547 should have
four 10nF bypass capacitors connected to each V+
and V- pin, as close to the package as possible. For
single-supply operation, the MAX4547 should have two
10nF bypass capacitors connected (one to each V+
pin), as close to the package as possible.
______________________________________________________________________________________
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
82Ω
(194Ω)
10nF
12
V+
LOGIC
IN
1 IN1
IN2 16
2 COM1
50Ω
IN/OUT
3
COM2 15
GND1
GND2
MAX4546
4 NO1
6 NC4
7
50Ω
OUT/IN
NO2 13
NC3 11
GND3
GND4
14
10
COM3 9
8 COM4
V38Ω
(61Ω)
38Ω
(61Ω)
5
10nF
V-
IC sockets degrade high-frequency performance and
should not be used if signal bandwidth exceeds 5MHz.
Surface-mount parts, having shorter internal lead
frames, provide the best high-frequency performance.
Keep all bypass capacitors close to the device, and
separate all signal leads with ground planes. Such
grounds tend to be wedge-shaped as they get closer to
the device. Use vias to connect the ground planes on
each side of the board, and place the vias in the apex of
the wedge-shaped grounds that separate signal leads.
Logic-level signal lead placement is not critical.
Impedance Matching
The typical on-resistances of the switches in the
MAX4545/MAX4546/MAX4547 are 14Ω, but the offstate impedances are approximately equal to a 6pF
capacitor. In coaxial systems, therefore, it is impossible
to match any impedance for both the on and off state. If
impedance matching is critical, the MAX4546 is best
suited, since its two sections can be configured as a
single on/off switch, as shown in Figure 2. This circuit
“wastes” switches and has higher losses, but has better off isolation and maintains good impedance matching in both the on and off states. The resistance values
shown in Figure 3 are optimized with ±5V supplies for
both 50Ω and 75Ω systems at room temperature.
LOGIC
SWITCH
0
OFF
Multiplexer
1
ON
With its excellent off isolation, the MAX4545 is ideal for
use in high-frequency video multiplexers. Figure 3
shows such an application for switching any one of four
video inputs to a single output. The same circuit may
be used as a demultiplexer by simply reversing the signal direction.
Stray capacitance of traces and the output capacitance
of switches placed in parallel reduces bandwidth, so the
outputs of no more than four individual switches should
be placed in parallel if high bandwidth is to be maintained. If more than four mux channels are needed, the
4-channel circuit should be duplicated and cascaded.
SWITCHES SHOWN FOR LOGIC “0” INPUT
( ) ARE FOR 75 SYSTEMS.
Figure 2. Impedance Matching On/Off Switch
On the MAX4545, GND5 and GND6 should always be
connected to the ground plane with solid copper to
improve isolation and crosstalk.
Signal Routing
Keep all signal leads as short as possible. Separate all
signal leads from each other and other traces with the
ground plane on both sides of the board. Where possible, use coaxial cable instead of printed circuit board
traces.
______________________________________________________________________________________
11
MAX4545/MAX4546/MAX4547
Board Layout
V+
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
10nF
1
1
2
2
3
3
4
V+
GND5
OUT
GND6
V+
MAX4545
COM1
MAX4545
1
4
50/75Ω
OUT/IN
2
3
NO1
GND1
OUT
COM2
NO2
GND2
MAX4545
COM3
4
NO3
GND3
ADDRESS
DECODING
COM4
NO4
GND4
5
6
7
8
TO
ADDITIONAL
MUXES
2
3
IN1
OUT
1
MAX4545
4
IN2
IN3
IN4
IN1
IN2
IN3
IN4
V10nF
VMORE THAN 4 CHANNELS
2 TO 4 CHANNELS
Figure 3. 4-Channel Multiplexer
12
______________________________________________________________________________________
50/75Ω
OUT/IN
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
10nF +5V
V+
NO_OR NC_
V+
VIN_
3V
50%
50%
0V
MAX4545
MAX4546
MAX4547
VIN_
IN_
90%
VOUT
COM_
V-
GND_
VOUT
90%
0V
RL = 50Ω
50Ω
tON
tOFF
10nF
-5V
ALL GND_ PINS ARE CONNECTED TO GROUND PLANE (OV).
V- IS CONNECTED TO GND (OV) FOR SINGLE-SUPPLY OPERATION.
REPEAT TEST FOR EACH SWITCH.
Figure 4. Switching Time
10nF +5V
V+
* COM3
3V
* COM2
MAX4546 * N02
VIN_
IN_
VOUT
* NC3
GND_
tR < 20ns
tF < 20ns
V+
VRL = 50Ω
50Ω
50%
VIN_
0V
10nF
-5V
80%
* REPEAT TEST FOR OTHER PAIR OF SWITCHES.
VOUT
10nF -+5V
0V
tBBM
V+
**NC_
1V
ALL GND_ PINS ARE CONNECTED TO GROUND PLANE (OV).
V+ IS CONNECTED TO GND (OV) FOR SINGLE-SUPPLY OPERATION.
**NO_
MAX4547
VIN_
IN_
**COM_
V-
GND_
VOUT
RL = 50Ω
50Ω
10nF
-5V
** REPEAT TEST FOR OTHER SWITCH.
Figure 5. Break-Before-Make Interval (MAX4546/MAX4547 only)
______________________________________________________________________________________
13
MAX4545/MAX4546/MAX4547
______________________________________________Test Circuits/Timing Diagrams
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
_________________________________Test Circuits/Timing Diagrams (continued)
10nF +5V
V+
NO_ OR NC_
V+
VIN_
VNO = 0V
0V
MAX4545
MAX4546
MAX4547
VIN_
IN_
COM_
GND_
V-
∆VOUT
VOUT
VOUT
CL = 1000pF
50Ω
10nF
∆VOUT IS THE MEASURED VOLTAGE DUE TO CHARGE TRANSFER
ERROR Q WHEN THE CHANNEL TURNS OFF.
-5V
Q = ∆VOUT x CL
V- IS CONNECTED TO GND (0V) FOR SINGLE-SUPPLY OPERATION.
Figure 6. Charge Injection
+5V 10nF
V
OFF ISOLATION = 20log OUT
VIN
NETWORK
ANALYZER
0V OR V+
V+
IN_
NO_
MAX4545
MAX4546
MAX4547 COM_
GND_
V-
50Ω
VIN
VOUT
V
ON LOSS = 20log OUT
VIN
50Ω
MEAS
50Ω
REF
V
CROSSTALK = 20log OUT
VIN
50Ω
10nF -5V
MEASUREMENTS ARE STANDARDIZED AGAINST SHORT AT IC TERMINALS.
OFF ISOLATION IS MEASURED BETWEEN COM_ AND "OFF" NO_ OR NC_ TERMINAL ON EACH SWITCH.
ON LOSS IS MEASURED BETWEEN COM_ AND "ON" NO_ OR NC_TERMINAL ON EACH SWITCH.
CROSSTALK IS MEASURED FROM ONE CHANNEL TO ALL OTHER CHANNELS.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.
V- IS CONNECTED TO GND (0V) FOR SINGLE-SUPPLY OPERATION.
Figure 7. On Loss, Off Isolation, and Crosstalk
14
______________________________________________________________________________________
Quad/Dual, Low-Voltage,
Bidirectional RF/Video Switches
_________________Chip Topographies
MAX4545
10nF +5V
0V OR V+
COM1
V+
IN_
IN1 IN2
COM2
GND2
N.C.
NO_
0.101"
(2.565mm)
GND1
NC_
MAX4545
MAX4546
MAX4547
GND_
NO2
1MHz
CAPACITANCE
ANALYZER
COM_
V-
V+
NO1
GND6
VGND5
NO3
NO4
10nF
GND3
-5V
ALL GND_ PINS ARE CONNECTED TO GROUND PLANE (0V).
N.C.
GND4
COM4
Figure 8. NO_, NC_, COM_ Capacitance
IN4 IN3
COM3
0.085"
(2.159mm)
MAX4546
COM1
IN1 IN2
MAX4547
COM2
NO1
GND2
0.101"
(2.565mm)
N.C.
GND1
IN1 IN2
V+
GND2
0.101"
(2.565mm)
VGND1
NO2
V+
NO1
N.C.
VN.C.
NC3
NC4
N.C.
N.C.
N.C.
N.C.
COM2
COM1
N.C.
N.C.
GND3
N.C.
N.C.
GND4
COM4 COM3
GND3
0.085"
(2.159mm)
N.C. = NO INTERNAL CONNECTION
V-
GND4
V+
NC1 IN2
NC2
0.085"
(2.159mm)
TRANSISTOR COUNT: 253
SUBSTRATE INTERNALLY CONNECTED TO V-
______________________________________________________________________________________
15
MAX4545/MAX4546/MAX4547
Test Circuits/Timing
______________Diagrams (continued)
___________________________________________Ordering Information (continued)
PART
MAX4545CAP
MAX4545C/D
TEMP. RANGE
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 SSOP
Dice*
MAX4545EPP
MAX4545EWP
MAX4545EAP
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
20 Plastic DIP
20 Wide SO
20 SSOP
MAX4546CPE
MAX4546CSE
MAX4546CEE
0°C to +70°C
0°C to +70°C
0°C to +70°C
16 Plastic DIP
16 Narrow SO
16 QSOP
MAX4546C/D
MAX4546EPE
MAX4546ESE
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
Dice*
16 Plastic DIP
16 Narrow SO
TEMP. RANGE
PIN-PACKAGE
MAX4546EEE
MAX4547CPE
MAX4547CSE
PART
-40°C to +85°C
0°C to +70°C
0°C to +70°C
16 QSOP
16 Plastic DIP
16 Narrow SO
MAX4547CEE
MAX4547C/D
MAX4547EPE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
16 QSOP
Dice*
16 Plastic DIP
MAX4547ESE
MAX4547EEE
-40°C to +85°C
-40°C to +85°C
16 Narrow SO
16 QSOP
*Contact factory for dice specifications.
________________________________________________________Package Information
QSOP.EPS
MAX4545/MAX4546/MAX4547
Quad/Dual, Low-Voltage,
Bidirectional RF/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
© 1997 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.