Maxim MAX4506CSA Fault-protected, high-voltage signal-line protector Datasheet

19-1415; Rev 1; 8/99
Fault-Protected, High-Voltage
Signal-Line Protectors
The MAX4506/MAX4507 multiple, two-terminal signal-line
protectors are pin-compatible with the industry-standard
MAX366/MAX367. These new circuit protectors feature
fault-protected inputs and Rail-to-Rail® signal handling
capability. The input pins are protected from overvoltage
faults up to ±36V with power on or ±40V with power off.
During a fault condition, the input terminal becomes an
open circuit and only nanoamperes of leakage current
flow from the source; but the switch output (OUT_) furnishes typically 19mA from the appropriate polarity supply to the load. This ensures unambiguous rail-to-rail
outputs when a fault begins and ends.
The MAX4506 contains three independent protectors
while the MAX4507 contains eight independent protectors. They can protect both unipolar and bipolar analog
signals using either unipolar (+9V to +36V) or bipolar
(±8V to ±18V) power supplies.
These devices have no logic control inputs; the protectors are designed to be always-on when the supplies
are on. On-resistance is 100Ω max and matched within
7Ω, and on-leakage is less than 0.5nA at TA = +25°C.
The MAX4506 is available in 8-pin SO/DIP packages.
The MAX4507 is available in 20-pin SSOP and 18-pin
SO/DIP packages.
Features
♦ Overvoltage Protection
±40V with Power Off
±36V with Power On
♦ Open Signal Paths with Power Off
♦ Output Clamps to Either Rail with an Input
Overvoltage
♦ Any On Channel Output is Not Affected
by an Overvoltage to Any Other Channel
♦ 100Ω max On-Resistance
♦ 10ns Overvoltage Turn-On Delay
♦ No Latchup During Power Sequencing
♦ Rail-to-Rail Signal Handling
♦ 500Ω Output Clamp Resistance During
Overvoltage
Ordering Information
PART
TEMP. RANGE
MAX4506CSA
0°C to +70°C
8 SO
MAX4506CPA
0°C to +70°C
8 Plastic DIP
MAX4506C/D
0°C to +70°C
Dice*
Process-Control Systems
MAX4506ESA
-40°C to +85°C
8 SO
Hot-Insertion Boards/Systems
MAX4506EPA
MAX4506MJA
-40°C to +85°C
-55°C to +125°C
8 Plastic DIP
8 CERDIP**
Applications
Data-Acquisition Systems
PIN-PACKAGE
Ordering Information continued at end of data sheet.
*Contact factory for dice specifications.
**Contact factory for availability.
Redundant/Backup Systems
ATE Equipment
Sensitive Instruments
Pin Configurations
Typical Operating Circuit
SWITCHED +15V
TOP VIEW
P
MAX4506
V+
1 IN1
OUT1 7
2 IN2
OUT2 6
3 IN3
OUT3 5
4
+15V
8
IN1 1
8
V+
7
OUT1
3
6
OUT2
V- 4
5
OUT3
IN2 2
MAX4506
100k
IN3
OP AMP
V-
SO/DIP
-15V
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
Pin Configurations continued at end of data sheet.
________________________________________________________________ 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.
MAX4506/MAX4507
General Description
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND)
V+ ........................................................................-0.3V to +44.0V
V- .........................................................................-44.0V to +0.3V
V+ to V-................................................................-0.3V to +44.0V
IN_ or OUT_ .........................................................................±44V
IN_ Overvoltage with Power On...........................................±36V
IN_ Overvoltage with Power Off...........................................±40V
Continuous Current into Any Terminal..............................±30mA
Peak Current into Any Terminal
(pulsed at 1ms, 10% duty cycle).................................±70mA
Continuous Power Dissipation (TA = +70°C)
8-Pin Narrow SO (derate 5.88mW/°C above +70°C) ....471mW
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .....727mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C) ...........640mW
18-Pin Wide SO (derate 9.52mW/ °C above +70°C) .......762mW
18-Pin Plastic DIP (derate 11.11mW/ °C above +70°C) ...889mW
18-Pin CERDIP (derate 10.53mW/ °C above +70°C) ......842mW
20-Pin SSOP (derate 11.11mW/°C above +70°C) ...........640mW
Operating Temperature Ranges
MAX4506C_A /MAX4607C_ _ .............................0°C to +70°C
MAX4506E_A/MAX4607E_ _ ...........................-40°C to +85°C
MAX4506MJA/MAX4607MJN ........................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
RECOMMENDED OPERATING GUIDELINES
V+ to GND ..............................................................-0.3V to +40V
IN_ to OUT_..........................................................40V Differential
V- to GND ...............................................................-32V to +0.3V
Continuous Current into Any Terminal ..............................≤30mA
V+ to V- ..................................................................................40V
Peak Current into Any Terminal
IN_........................................................................................±40V
(pulsed at 1ms, 10% duty cycle) .................................≤70mA
OUT_ ...............................................................................V+ to VNote 1: OUT_ pins are not fault protected. Signals on OUT_ exceeding V+ or V- are clamped by internal diodes. Limit forward-diode
current to maximum current rating.
Note 2: IN_ pins are fault protected. Signals on IN_ exceeding -36V to +36V may damage the device. These limits apply with power
applied to V+ or V-, or ±40V with V+ = V- = 0.
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
(V+ = +15V, V- = -15V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
C, E, M
V-
TYP
MAX
UNITS
V+
V
ANALOG SWITCH
Fault-Free Analog Signal Range
(Note 4)
VIN_
V+ = +15V, V- = -15V,
VIN_ = ±15V
Analog Signal-Path Resistance
RON
VIN_ = ±10V, IOUT_ = 1mA
65
+25°C
125
M
150
1
+25°C
Signal-Path Resistance Match
(Note 6)
Signal-Path Leakage Current
(Note 7)
Input Capacitance
∆RON
IOUT_ON
VIN_ = VOUT_ = ±10V, IOUT = 1mA
VOUT_ = ±10V, VIN_ = ±10V or
floating
CIN
VIN = 0, f = 1MHz
Fault-Protected Analog Signal
Range
VIN_
(Notes
2, 3)
Input Signal-Path Leakage
Current, Supplies On
IIN_
VIN_= ±25V, VOUT_ = open
100
C, E
7
C, E
10
M
12
+25°C
-0.5
C, E
-20
20
M
-400
400
+25°C
Ω
Ω
0.5
20
nA
pF
FAULT PROTECTION
2
Applies with power on
C, E, M
-36
36
Applies with power off
C, E, M
-40
40
+25°C
-20
C, E
-200
0.1
200
M
-10
10
_______________________________________________________________________________________
20
V
nA
µA
Fault-Protected, High-Voltage
Signal-Line Protectors
(V+ = +15V, V- = -15V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
Input Signal-Path Leakage
Current, Supplies Off
SYMBOL
IIN_
Output Clamp Current,
Supplies On
IOUT_
Output Clamp Resistance,
Supplies On
ROUT_
CONDITIONS
VIN_= ±40V, VOUT_ = open,
V+ = 0, V- = 0
TA
MIN
TYP
MAX
+25°C
-20
0.2
20
C, E
-500
500
M
-10
VIN_= +25V
+25°C
13
19
26
VIN_= -25V
+25°C
-26
-19
-13
IOUT = 1mA
10
VIN_= +25V
+25°C
0.5
1.0
VIN_= -25V
+25°C
0.4
1.0
UNITS
nA
µA
mA
kΩ
± Fault Output Turn-On Delay
Time (Note 5)
RL = 10kΩ, VIN_ = ±25V
+25°C
10
ns
± Fault Recovery Time (Note 5)
RL = 10kΩ, VIN_ = ±25V
+25°C
2.5
µs
POWER SUPPLY
Power-Supply Range
V+, V-
C, E, M
±8
90
+25°C
MAX4506
I+
Power-Supply Current
175
M
200
160
MAX4506
IMAX4507
250
300
C, E
400
M
VIN_ = +15V
V
150
C, E
+25°C
MAX4507
±18
+25°C
-150
C, E
-175
M
-200
+25°C
-250
C, E
-300
M
-400
-90
µA
µA
-160
ELECTRICAL CHARACTERISTICS—Single Supply
(V+ = +12V, V- = -0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
C, E, M
0
TYP
MAX
UNITS
V+
V
ANALOG SWITCH
Fault-Free Analog Signal Range
(Note 4)
VIN_
V+ = +12V, V- = 0
VIN_ = +12V
125
+25°C
Analog Signal-Path Resistance
RON
VIN_ = +10V, IOUT_ = 1mA
C, E
250
M
300
+25°C
Signal-Path Resistance Match
(Note 6)
∆RON
VIN_ = +10V, IOUT_ = 1mA
IOUT_(ON)
VIN = +10V or floating
3
15
M
20
-0.5
0.05
Ω
12
C, E
+25°C
Signal-Path Leakage Current
(Note 7)
200
Ω
0.5
C, E
-20
20
M
-400
400
nA
_______________________________________________________________________________________
3
MAX4506/MAX4507
ELECTRICAL CHARACTERISTICS —Dual Supplies (continued)
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
ELECTRICAL CHARACTERISTICS—Single Supply (continued)
(V+ = +12V, V- = -0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
TA
MIN
TYP
MAX
Applies with power on
C, E, M
-36
36
Applies with power off
C, E, M
-40
40
UNITS
FAULT PROTECTION
Fault-Protected Analog Signal
Range (Notes 4, 5, 9)
VIN_
Input Signal-Path Leakage
Current, Supply On (Note 9)
IIN_
Input Signal-Path Leakage
Current, Supply Off (Note 9)
IIN_
VIN_= ±25V, VOUT_ = 0
VIN_= ±40V
+25°C
-20
C, E
-200
0.2
200
M
-10
10
0.2
20
20
V
nA
µA
+25°C
-20
C, E
-500
500
M
-10
10
µA
3
5.5
10
mA
2.5
kΩ
nA
Output Clamp Current,
Supply On
IOUT_
VIN_= 25V
+25°C
Output Clamp Resistance,
Supply On
ROUT_
VIN_= ±25V
+25°C
1.0
± Fault Output Turn-On Delay
Time (Note 5)
RL = 10kΩ, VIN_ = +25V
+25°C
10
ns
± Fault Recovery Time (Note 5)
RL = 10kΩ, VIN_ = +25V
+25°C
2.5
µs
POWER SUPPLY
Power-Supply Range
V+
C, E, M
+25°C
MAX4506
Power-Supply Current
I+
4
+36
9
+25°C
V
25
30
C, E
40
M
VIN_ = +12V
MAX4507
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
+9
17
40
C, E
60
M
80
µA
The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
See Fault-Free Analog Signal Range vs. Supply Voltages graph in the Typical Operating Characteristics.
Guaranteed by design.
∆RON = RON(MAX) - RON(MIN)
Leakage parameters are 100% tested at maximum rated hot temperature and guaranteed by correlation at TA = +25°C.
Leakage testing for single-supply operation is guaranteed by testing with dual supplies.
Guaranteed by testing with dual supplies.
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
ON-RESISTANCE vs. OUTPUT VOLTAGE
(SINGLE SUPPLY)
100
200
RON (Ω)
60
V+ = +20V
100
100
V+ = +18V
V- = -18V
20
TA = +125°C
TA = +85°C
TA = +70°C
60
TA = +25°C
TA = -40°C
40
V+ = +30V
40
V+ = +15V
V- = -15V
80
150
50
MAX4506/07 toc03
V+ = +9V
120
V+ = +12V
V+ = +15V
V- = -15V
80
V- = 0V
RON (Ω)
120
RON (Ω)
V+ = +8V
V- = -8V
V+ = +10V
V- = -10V
250
MAX4506/07 toc01
140
ON-RESISTANCE vs. OUTPUT VOLTAGE
AND TEMPERATURE (DUAL SUPPLIES)
MAX4506/07 toc02
ON-RESISTANCE vs. OUTPUT VOLTAGE
(DUAL SUPPLIES)
TA = -55°C
20
V+ = +36V
0
-15
-10
-5
0
5
10
15
0
20
5
10
15
20
25
30
35
-15
10
0.4
IOUT (mA)
TA = -40°C TA = +25°C
15
VIN = +25V
0.5
VIN = -25V
0.3
-20
6
8
10
12
-25
-55 -35 -15
-5
25
45
65
85 105 125
-55 -40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT TRANSFER CHARACTERISTICS
(DUAL SUPPLIES)
OUTPUT TRANSFER CHARACTERISTICS
(SINGLE SUPPLY)
FAULT-FREE ANALOG SIGNAL RANGE
vs. SUPPLY VOLTAGE
10
5
INPUT VOLTAGE
LINEARLY SWEPT
BETWEEN -30V
AND +30V
(V+ = +8V, V- = -8V)
(V+ = +10V, V- = -10V)
(V+ = +15V, V- = -15V)
(V+ = +18V, V- = -18V)
OUTPUT LOAD = 1MΩ
-30
-20
-10
0
10
INPUT VOLTAGE (V)
20
35
30
V+ = +25V
25
20
V+ = +15V
15
V+ = +12V
10
V+ = +9V
5
INPUT VOLTAGE LINEARLY SWEPT
BETWEEN 0 AND 35V
0
30
V+ = +36V
0
5
10
15
20
25
INPUT VOLTAGE (V)
30
35
20
MAX4506/07 toc09
(V+ = +10V, V- = -10V)
(V+ = +8V, V- = -8V)
OUTPUT LOAD = 1MΩ
V- = 0
15
OUTPUT VOLTAGE (V)
15
40
MAX4506/07 toc08
(V+ = +18V, V- = -18V)
(V+ = +15V, V- = -15V)
OUTPUT CLAMP VOLTAGE (V)
MAX4506/07 toc07
VOUT_ (V)
20
OUTPUT CLAMP VOLTAGE (V)
4
0
-5
-15
0
2
5
-10
0.2
0.1
0
V+ = +15V
V- = -15V
20
MAX4506/07 toc06
0.6
ROUT (kΩ)
TA = +85°C
V+ = +15V
V- = -15V
VIN = ±25V
0.7
25
MAX4506/07 toc05
TA = +125°C
0.8
MAX4506/07 toc04
V+ = +12V
V- = 0
50
-20
15
OUTPUT CLAMP CURRENT SUPPLIES ON
vs. TEMPERATURE
TA = -55°C
-15
10
OUTPUT CLAMP RESISTANCE SUPPLIES ON
100
-10
5
ON-RESISTANCE vs. OUTPUT VOLTAGE
AND TEMPERATURE (SINGLE SUPPLY)
TA = +70°C
-5
0
VOUT_ (V)
150
0
-5
VOUT_ (V)
200
0
-10
VOUT_ (V)
250
RON (Ω)
0
0
-20
10
5
0
-5
-10
-15
-20
40
-20
-15
-10
-5
0
5
10
15
20
INPUT VOLTAGE (V)
_______________________________________________________________________________________
5
MAX4506/MAX4507
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
IOUT (V+ = +12V, V- = 0)
10p
10n
1n
100p
1p
IIN AT +25V (V+ = +12V, V - = 0)
10p
0.1p
0.1p
-30
-5
20
45
70
95
120 145
5
25
45
65
MAX4507
POWER-SUPPLY CURRENT vs.
TEMPERATURE
SUPPLY CURRENT vs.
INPUT VOLTAGE
150
100
50
I+ SINGLE SUPPLY + 12V
0
-50
-100
40
20
0
-20
-40
-250
-100
-55 -35 -15
I+
60
-80
5
25
45
65
MAX45506/07 toc12
-25
-50
-75
I-
25
45
65
85 105 125
10
BANDWIDTH
0
-10
-20
-30
V+ = +15V
V- = -15V
-40
CROSSTALK
-50
-60
-70
-80
I-15
85 105 125
5
FREQUENCY RESPONSE
80
-200
I+ SINGLE SUPPLY +12V
TEMPERATURE (°C)
-60
I-
25
0
-55 -35 -15
RESPONSE (dB)
V+ = +15V
V- = -15V
I+
100
SUPPLY CURRENT (µA)
200
I+
50
85 105 125
TEMPERATURE (°C)
250
-150
-55 -35 -15
TEMPERATURE (°C)
MAX45506/07 toc13
-55
V+ = +15V
V- = -15V
-100
-125
-150
1p
0.01p
150
125
100
75
MAX4506/07 toc15
100p
IIN AT +25V (V+ = +15V, V- = -15V)
SUPPLY CURRENT (µA)
IOUT (V+ = +15V, V- = -15V)
1n
100n
MAX45506/07 toc14
LEAKAGE CURRENT (A)
10n
1µ
MAX45506/07 toc11
VOUT = ±10υ
MAX4506
POWER-SUPPLY CURRENT
vs. TEMPERATURE
INPUT FAULT LEAKAGE CURRENT
WITH SUPPLIES ON
LEAKAGE CURRENT (A)
100n
MAX45506/07 toc10
FAULT-FREE OUTPUT LEAKAGE CURRENT
WITH SUPPLIES ON
SUPPLY CURRENT (µA)
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
TEMPERATURE (°C)
-90
10
5
0
5
INPUT VOLTAGE (V)
10
-100
0.01
15
MAX45506/07 toc16
1
10
100
1000
FREQUENCY (MHz)
INPUT OVERVOLTAGE
vs. OUTPUT CLAMPING
FAULT-FREE SIGNAL PERFORMANCE
0.1
FAULT RECOVERY
MAX45506/07 toc17
MAX45506/07 toc18
+25V
+15V
+16V
IN_
IN_
5V/div
IN_
10V/div
0V
-15V
+15V
+15V
OUT_
0V
10V/div
-25V
0V
OUT_
-15V
-15V
5µs/div
FAULT-FREE RAIL-TO-RAIL SIGNAL HANDLING
WITH ±15V SUPPLIES
6
0V
5µs/div
±25V OVERVOLTAGE INPUT WITH THE OUTPUT
CLAMPED AT ±15V
+15V
0V
OUT_
5V/div
V+ = +15V
V- = -15V
0V
5µs/div
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
PIN
MAX4506
MAX4507
NAME*
FUNCTION
8-Pin
DIP/SO
18-Pin
DIP/SO
20-Pin
SSOP
1, 2, 3
1, 2, 3
1, 2, 4
IN1, IN2, IN3
–
4–8
5–9
IN4, IN5, IN6, IN7, IN8
4
9
10
V-
–
10–14
11–15
OUT8, OUT7, OUT6, OUT5, OUT4
5, 6, 7
15, 16, 17
16, 17, 19
OUT3, OUT2, OUT1
8
18
20
V+
–
–
3, 18
N.C.
Signal Inputs 1, 2, 3
Signal Inputs 4, 5, 6, 7, 8
Negative Supply Voltage Input
Signal Outputs 8, 7, 6, 5, 4
Signal Outputs 3, 2, 1
Positive Supply-Voltage Input
No Connection. Not internally connected.
* Connect all unused inputs to a hard voltage within the supply range (e.g., V+, V-, or GND).
Detailed Description
The MAX4506/MAX4507 protect other ICs from overvoltage by clamping its output voltage to the supply
rails. If the power supplies to the device are off, the
device clamps the output to 0V. The MAX4506/
MAX4507 provide protection for input signals up to
±36V with the power supplies on and ±40V with the
power supplies off.
The MAX4506/MAX4507 protect other integrated circuits connected to its output from latching up. Latchup
is caused by parasitic SCR(s) within the IC turning on,
and can occur when the supply voltage applied to the
IC exceeds the specified operating range. Latchup can
also occur when signal voltage is applied before the
power-supply voltage. When in a latchup state, the circuit draws excessive current and may continue to draw
excessive current even after the overvoltage condition
is removed. A continuous latchup condition may damage the device permanently. Such “faults” are commonly encountered in modular control systems where
power supplies to interconnected modules may be
interrupted and reestablished at random. Faults can
happen during production testing, maintenance, startup, or a power failure.
Figure 1 shows the normal complementary pair (N1 and
P1) found in many common analog switches. In addition to these transistors, the MAX4506/MAX4507 also
contain comparators and sensing and clamping circuitry
to control the state of N1 and P1. During normal opera-
-15V
-15V
COMPARATOR
N3
N-CHANNEL
DRIVER
SENSE
SWITCH
-V(-15V)
CLAMP N2
N1
IN
OUT
CLAMP P2
P1
P3
SENSE
SWITCH
+15V
+15V
+V(+15V)
P-CHANNEL
DRIVER
COMPARATOR
Figure 1. Simplified Internal Structure
tion, N1 and P1 remain on with a typical 65Ω on-resistance between IN and OUT.
The on-board comparators and sensing circuitry monitor the input voltage for possible overvoltage faults.
_______________________________________________________________________________________
7
MAX4506/MAX4507
Pin Description
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
Two clamp circuits limit the output voltage to within the
supply voltages. When the power supplies are off, any
input voltage applied at IN turns off both N1 and P1,
and OUT is clamped to 0V.
Normal Operation
MAX4506
When power is applied, each protector acts as a resistor in series with the signal path. Any voltage source on
the “input” side of the switch will be conducted through
the protector to the output (Figure 2).
When the output load is resistive, it draws current
through the protector. The internal resistance is typically
less than 100Ω. High-impedance loads are relatively
unaffected by the presence of the MAX4506/MAX4507.
The protector’s path resistance is a function of the supply
voltage and the signal voltage (see Typical Operating
Characteristics).
Fault Protection, Power Off
V-
4
V-
V+
1 IN1
OUT1
8
V+
7
VIN
ROUT
Figure 2. Application Circuit
When power is off (i.e., V+ = V- = 0), the protector is a
virtual open circuit. With up to ±40V applied to the input
pin, the output pin will be 0V.
+15V
Fault Protection, Power On
A fault condition exists when the voltage on the IN_
exceeds either supply rail. This definition is valid when
power is on or off, as well as during all states while
power ramps up or down.
Applications Information
MAX4506
V+
8
10µF
1 IN1
OUT1 7
2 IN2
OUT2 6
3 IN3
OUT3 5
100k
Supplying Power Through External ICs
The MAX4506/MAX4507 have low supply currents
(<250µA), which allows the supply pins to be driven by
other active circuitry instead of connected directly to
the power sources. In this configuration, the parts can
be used as driven fault-protected switches with V+ or
V- used as the control pins. For example, with the Vpin grounded, the output of a CMOS gate can drive the
V+ pin to turn the device on and off. This can effectively
connect and disconnect three (MAX4506) or eight
(MAX4507) separate signal lines at once. Ensure that
the driving source(s) does not drive the V+ pin more
negative than the V- pin.
Figure 3 shows a simple turn-on delay that takes
advantage of the MAX4506’s low power consumption.
The two RC networks cause gradual application of
power to the MAX4506, which in turn applies the input
signals smoothly after the amplifier has stabilized. The
8
OP AMP
4
V-
10µF
100k
-15V
Figure 3. Turn-On Delay
two diodes discharge the two capacitors rapidly when
the power turns off. Note that the IC used to supply
power to the MAX4506/MAX4507 must be able to supply enough current to maintain the load voltage at the
supply rail in a fault condition.
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
Figure 5 shows MAX4506 used in front of a MAX338
unprotected 1-to-8 multiplexer. With supplies at ±15V,
VOUT of the MAX4506 clamps to ±15V; V OUT of the
MAX338 goes to ±14V. With supplies off, VOUT goes to
0V while the inputs remain at ±25V.
SWITCHED +15V
P
+15V
MAX4506
V+
8
1 IN1
OUT1 7
2 IN2
OUT2 6
Use the MAX4506 with a MAX338 to enhance voltage
handling capability (Figure 6). The MAX4506 and
MAX338 share almost equal voltage drops in this configuration. For example, applying ±40V on pins 1 and 2
of the MAX4506 causes a voltage drop of about 26V
across pin 1 of the MAX4506 to pin 4 of the MAX338,
and a voltage drop of about 28V across pin 4 of the
MAX4506 to pin 8 of the MAX338. Similarly, there is a
26V drop from pin 2 of the MAX4506 to pin 5 of the
MAX338. The system’s performance exceeds each
individual part’s specification because of shared voltage drops.
Multiplexer and Demultiplexer
As shown in Figure 7, the MAX4506 can be used in
series with the output of a MAX4508 (1-to-8 multiplexer)
to act as multiplexer or demultiplexer. The MAX4508 is a
fault-protected multiplexer whose inputs are designed to
interface with harsh environments; however, its common
output is not fault protected if connected to outside signals (i.e., demultiplexer use). If the common output can
see fault signals, then it needs to be protected, and the
MAX4506 can be added to provide complete protection.
100k
OP AMP
1
OUT3 5
3 IN3
4
VOUT = -14V
+40V
7
4
8
10k
V-
-40V
2
6
5
MAX4506
MAX338
-15V
Figure 4. Power-Supply Sequencing
Figure 6. SPDT Switch Application
+3V
OV
1
AO
A1 16
+5V 2
EN
-5V 3
V-
A2 15
GND
14
+25V 1
8 +15V
4
NO1 MAX338
-25V 2
7
5
NO2
NO5 12
6
NO3
NO6 11
7
NO4
NO7 10
8
VOUT
NO9 9
MAX4506
3
-15V 4
6
5
V+ 13 +15V
+3V
1
AO
A1 16
+5V 2
EN
-15V 3
V-
A2 15
GND
14
O
NEW COM
1
8 +15V
4
NO1 MAX4508 V+ 13 +15V
2
7
5
NO2
NO5 12
6
NO3
NO6 11
7
NO4
NO7 10
8
COM
NO9 9
MAX4506
3
-15V 4
6
5
RL
Figure 5. Protecting a MAX338 with a MAX4506
Figure 7. Multiplexer and Demultiplexer Application Using
MAX4506 (or MAX4507) with MAX4508
_______________________________________________________________________________________
9
MAX4506/MAX4507
Protectors as Circuit Elements
Each of the protectors in a MAX4506/MAX4507 may be
used as a switched resistor, independent of the functions of other elements in the same package. For example, Figure 4 shows a MAX4506 with two of the
protectors used to protect the input of an op amp, and
the third element used to sequence a power supply.
Combining the circuits of Figures 3 and 4 produces a
delayed action on the switched +15V, as well as
smooth application of signals to the amplifier input.
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
As seen in Figure 7, the signal input can now be put
into pin 1 of the MAX4506 (new common output for system), and outputs can be taken at MAX4508 pins 4 to
7, and 9 to 12. This is the classic demultiplexer operation. This system now has full protection on both of the
multiplexers’ inputs and outputs.
Measuring Path Resistance
Measuring path resistance requires special techniques,
since path resistance varies dramatically with the IN
and OUT voltages relative to the supply voltages.
Conventional ohmmeters should not be used for the following two reasons: 1) the applied voltage and currents
are usually not predictable, and 2) the true resistance is
a function of the applied voltage, which is dramatically
altered by the ohmmeter itself. Autoranging ohmmeters
are particularly unreliable.
Figure 8 shows a circuit that can give reliable results.
This circuit uses a 100mV voltage source, a low-voltage-drop ammeter as the measuring circuit, and an
adjustable supply to sweep the analog voltage across
its entire range. The ammeter must have a voltage drop
of less than one millivolt (up to the maximum test current) for accurate results. A Keithley model 617 electrometer has a suitable ammeter circuit, appropriate
ranges, and a built-in voltage source designed for this
type of measurement. Find the path resistance by setting the analog voltage, measuring the current, and calculating the path resistance. Repeat the procedure at
each analog and supply voltage.
Note: It is important to use a voltage source of 100mV
or less. As shown in Figure 8, this voltage and the VIN
voltage form the VOUT voltage. Using higher voltages
could cause OUT to go into a fault condition prematurely.
High-Voltage Surge Suppression
These devices are not high-voltage arresters, nor are
they substitutes for surge suppressors. However, the
MAX4506/MAX4507 can fill a vital gap in systems that
use these forms of protection (Figure 9). Although surge
suppressors are extremely fast shunt elements, they
have very soft current knees. Their clamp voltage must
be chosen well above the normal signal levels, because
they have excessive leakage currents as the analog
signal approaches the knee. This leakage current can
interfere with normal operation when signal levels are
low or impedance is high. If the clamp voltage is too
high, the input can be damaged.
Connecting a MAX4506/MAX4507 after a surge suppressor allows the surge-suppressor voltage to be set
above the supply voltage (but within the overvoltage
limits), dramatically reducing leakage effects (Figure 9).
During a surge, the surge suppressor clamps the input
voltage roughly to the ±10V supplies.
+10V
MAX4506
V+
A
100mV
8
1 IN1
OUT1 7
2 IN2
OUT2 6
3 IN3
OUT3 5
MAX4506
VIN IN1
OUT1
VOUT
OP AMP
ADJUSTABLE
ANALOG
VOLTAGE
4
V-
V+
8
4
V+
V-
PATH RESISTANCE = 100mv/A
SURGE SUPPRESSORS
-15V
Figure 8. Path-Resistance Measuring Circuit
10
Figure 9. Surge-Suppression Circuit
______________________________________________________________________________________
-10V
Fault-Protected, High-Voltage
Signal-Line Protectors
PART
TEMP. RANGE
PIN-PACKAGE
MAX4507CAP
0°C to +70°C
20 SSOP
MAX4507CWN
0°C to +70°C
18 SO
MAX4507CPN
0°C to +70°C
18 Plastic DIP
MAX4507C/D
0°C to +70°C
Dice*
MAX4507EAP
MAX4507EWN
MAX4507EPN
MAX4507MJN
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
20 SSOP
18 SO
18 Plastic DIP
18 CERDIP**
*Contact factory for dice specifications.
**Contact factory for availability.
Chip Topographies
MAX4507
MAX4506
V+
IN1
V+
OUT1
IN2
IN1
OUT2
OUT1
IN3
OUT3
IN2
0.112"
(2.84mm)
IN4
OUT4
IN5
OUT2
0.112"
(2.84mm)
OUT5
IN6
IN3
OUT6
V-
OUT3
IN7
OUT7
IN8
0.071"
(1.80mm)
V-
TRANSISTOR COUNT:
144 (MAX4506)
379 (MAX4507)
SUBSTRATE CONNECTED TO V+
OUT8
0.071"
(1.800mm)
______________________________________________________________________________________
11
MAX4506/MAX4507
Ordering Information (continued)
Pin Configurations (continued)
TOP VIEW
18 V+
IN1 1
20 V+
IN2 2
17 OUT1
IN2 2
19 OUT1
IN3 3
16 OUT2
N.C. 3
18 N.C.
15 OUT3
IN3 4
14 OUT4
IN4 5
13 OUT5
IN5 6
15 OUT4
IN7 7
12 OUT6
IN6 7
14 OUT5
IN8 8
11 OUT7
IN7 8
13 OUT6
V- 9
10 OUT8
IN8 9
12 OUT7
V- 10
11 OUT8
IN1 1
IN4 4
IN5 5
MAX4507
IN6 6
17 OUT2
MAX4507
16 OUT3
SO/DIP
SSOP
Package Information
SSOP.EPS
MAX4506/MAX4507
Fault-Protected, High-Voltage
Signal-Line Protectors
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.
12 ____________________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.