MAX4507EPN [MAXIM]
Fault-Protected, High-Voltage Signal-Line Protectors; 故障保护，高电压信号线保护
| 型号： | MAX4507EPN |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Fault-Protected, High-Voltage Signal-Line Protectors |
| 文件： | 总12页 (文件大小：395K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1415; Rev 1; 8/99
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
General Description
Features
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_) fur-
nishes typically 19mA from the appropriate polarity sup-
ply to the load. This ensures unambiguous rail-to-rail
outputs when a fault begins and ends.
♦ 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
The MAX4506 contains three independent protectors
while the MAX4507 contains eight independent protec-
tors. They can protect both unipolar and bipolar analog
signals using either unipolar (+9V to +36V) or bipolar
(±8V to ±18V) power supplies.
♦ 500Ω Output Clamp Resistance During
Overvoltage
These devices have no logic control inputs; the protec-
tors are designed to be always-on when the supplies
are on. On-resistance is 100Ω max and matched within
Ordering Information
7Ω, and on-leakage is less than 0.5nA at T = +25°C.
A
The MAX4506 is available in 8-pin SO/DIP packages.
The MAX4507 is available in 20-pin SSOP and 18-pin
SO/DIP packages.
PART
TEMP. RANGE
0°C to +70°C
PIN-PACKAGE
8 SO
MAX4506CSA
MAX4506CPA
MAX4506C/D
MAX4506ESA
MAX4506EPA
MAX4506MJA
0°C to +70°C
8 Plastic DIP
Dice*
Applications
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
8 SO
Process-Control Systems
Hot-Insertion Boards/Systems
Data-Acquisition Systems
Redundant/Backup Systems
ATE Equipment
8 Plastic DIP
8 CERDIP**
Ordering Information continued at end of data sheet.
*Contact factory for dice specifications.
**Contact factory for availability.
Sensitive Instruments
Pin Configurations
Typical Operating Circuit
SWITCHED +15V
TOP VIEW
P
IN1
IN2
IN3
V-
1
2
3
4
8
7
6
5
V+
+15V
MAX4506
8
7
V+
OUT1
OUT2
OUT3
IN1
IN2
OUT1
1
2
MAX4506
100k
OUT2
OUT3
6
5
OP AMP
-15V
IN3
V-
3
4
SO/DIP
Pin Configurations continued at end of data sheet.
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.
For small orders, phone 1-800-835-8769.
Fault-Protected, High-Voltage
Signal-Line Protectors
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND)
8-Pin CERDIP (derate 8.00mW/°C above +70°C) ...........640mW
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
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
(pulsed at 1ms, 10% duty cycle).................................±70mA
Continuous Power Dissipation (T = +70°C)
A
8-Pin Narrow SO (derate 5.88mW/°C above +70°C) ....471mW
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C).....727mW
RECOMMENDED OPERATING GUIDELINES
V+ to GND..............................................................-0.3V to +40V
V- to GND ...............................................................-32V to +0.3V
V+ to V- ..................................................................................40V
IN_........................................................................................±40V
OUT_ ...............................................................................V+ to V-
IN_ to OUT_..........................................................40V Differential
Continuous Current into Any Terminal ..............................≤30mA
Peak Current into Any Terminal
(pulsed at 1ms, 10% duty cycle) .................................≤70mA
6/MAX4507
Note 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, T = T
to T , unless otherwise noted. Typical values are at T = +25°C.) (Note 3)
MAX A
A
MIN
PARAMETER
SYMBOL
CONDITIONS
T
A
MIN
TYP
MAX
UNITS
ANALOG SWITCH
Fault-Free Analog Signal Range
(Note 4)
V+ = +15V, V- = -15V,
V
R
C, E, M
V-
V+
V
IN_
V
= ±15V
IN_
+25°C
C, E
M
65
1
100
125
150
7
Analog Signal-Path Resistance
V
= ±10V, I
= 1mA
Ω
IN_
OUT_
ON
+25°C
C, E
M
Signal-Path Resistance Match
(Note 6)
∆R
V
V
= V
= ±10V, I = 1mA
OUT
10
Ω
ON
IN_
OUT_
12
+25°C
C, E
M
-0.5
-20
0.5
20
Signal-Path Leakage Current
(Note 7)
= ±10V, V
= ±10V or
OUT_
IN_
I
nA
pF
OUT_ON
floating
-400
400
Input Capacitance
C
V
IN
= 0, f = 1MHz
+25°C
20
IN
FAULT PROTECTION
Applies with power on
Applies with power off
C, E, M
C, E, M
+25°C
C, E
-36
-40
36
40
Fault-Protected Analog Signal
Range
(Notes
2, 3)
V
V
IN_
-20
0.1
20
nA
µA
Input Signal-Path Leakage
Current, Supplies On
I
V
= ±25V, V
= open
-200
-10
200
10
IN_
IN_
OUT_
M
2
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
ELECTRICAL CHARACTERISTICS —Dual Supplies (continued)
(V+ = +15V, V- = -15V, T = T
to T , unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
MAX
A
MIN
PARAMETER
SYMBOL
CONDITIONS
= ±40V, V = open,
T
MIN
-20
-500
-10
13
TYP
MAX
20
UNITS
nA
A
+25°C
C, E
0.2
Input Signal-Path Leakage
Current, Supplies Off
V
IN_
OUT_
I
500
10
IN_
V+ = 0, V- = 0
M
µA
V
V
= +25V
= -25V
+25°C
+25°C
+25°C
+25°C
19
-19
0.5
0.4
26
IN_
IN_
Output Clamp Current,
Supplies On
I
mA
OUT_
-26
-13
1.0
1.0
V
V
= +25V
= -25V
IN_
Output Clamp Resistance,
Supplies On
R
I
= 1mA
kΩ
OUT_
OUT
IN_
± Fault Output Turn-On Delay
Time (Note 5)
R = 10kΩ, V
= ±25V
= ±25V
+25°C
+25°C
10
ns
µs
L
IN_
IN_
± Fault Recovery Time (Note 5)
POWER SUPPLY
R = 10kΩ, V
L
2.5
Power-Supply Range
V+, V-
I+
C, E, M
+25°C
C, E
M
±8
±18
150
175
200
250
300
400
V
90
160
-90
MAX4506
MAX4507
MAX4506
MAX4507
+25°C
C, E
M
Power-Supply Current
V
= +15V
µA
IN_
+25°C
C, E
M
-150
-175
-200
-250
-300
-400
I-
+25°C
C, E
M
-160
ELECTRICAL CHARACTERISTICS—Single Supply
(V+ = +12V, V- = -0V, T = T
to T , unless otherwise noted. Typical values are at T = +25°C.) (Note 3)
MAX A
A
MIN
PARAMETER
SYMBOL
CONDITIONS
T
A
MIN
TYP
MAX
UNITS
ANALOG SWITCH
Fault-Free Analog Signal Range
(Note 4)
V+ = +12V, V- = 0
V
R
C, E, M
0
V+
V
IN_
V
= +12V
IN_
+25°C
C, E
M
125
3
200
250
300
12
Analog Signal-Path Resistance
V
= +10V, I
= 1mA
= 1mA
Ω
IN_
OUT_
OUT_
ON
+25°C
C, E
M
Signal-Path Resistance Match
(Note 6)
∆R
V
V
= +10V, I
Ω
15
IN_
ON
20
+25°C
C, E
M
-0.5
-20
0.05
0.5
20
Signal-Path Leakage Current
(Note 7)
I
= +10V or floating
IN
nA
OUT_(ON)
-400
400
_______________________________________________________________________________________
3
Fault-Protected, High-Voltage
Signal-Line Protectors
ELECTRICAL CHARACTERISTICS—Single Supply (continued)
(V+ = +12V, V- = -0V, T = T
to T , unless otherwise noted. Typical values are at T = +25°C.) (Note 3)
MAX A
A
MIN
PARAMETER
SYMBOL
CONDITIONS
T
A
MIN
TYP
MAX
UNITS
FAULT PROTECTION
Applies with power on
Applies with power off
C, E, M
C, E, M
+25°C
C, E
-36
-40
36
40
Fault-Protected Analog Signal
Range (Notes 4, 5, 9)
V
V
IN_
-20
0.2
0.2
20
nA
µA
nA
µA
mA
Input Signal-Path Leakage
Current, Supply On (Note 9)
I
I
V
V
= ±25V, V
= 0
OUT_
-200
-10
200
10
IN_
IN_
IN_
M
+25°C
C, E
-20
20
Input Signal-Path Leakage
Current, Supply Off (Note 9)
= ±40V
-500
-10
500
10
IN_
M
Output Clamp Current,
Supply On
I
V
V
= 25V
+25°C
+25°C
3
5.5
1.0
10
OUT_
IN_
IN_
Output Clamp Resistance,
Supply On
R
= ±25V
2.5
kΩ
6/MAX4507
OUT_
± Fault Output Turn-On Delay
Time (Note 5)
R = 10kΩ, V
= +25V
= +25V
+25°C
+25°C
10
ns
µs
L
IN_
IN_
± Fault Recovery Time (Note 5)
POWER SUPPLY
R = 10kΩ, V
L
2.5
Power-Supply Range
V+
I+
C, E, M
+25°C
C, E
M
+9
+36
25
30
40
40
60
80
V
9
MAX4506
Power-Supply Current
V
= +12V
µA
IN_
+25°C
C, E
M
17
MAX4507
Note 3: The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.
Note 4: See Fault-Free Analog Signal Range vs. Supply Voltages graph in the Typical Operating Characteristics.
Note 5: Guaranteed by design.
Note 6: ∆R
= R
- R
ON
ON(MAX) ON(MIN)
Note 7: Leakage parameters are 100% tested at maximum rated hot temperature and guaranteed by correlation at T = +25°C.
A
Note 8: Leakage testing for single-supply operation is guaranteed by testing with dual supplies.
Note 9: Guaranteed by testing with dual supplies.
4
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
ON-RESISTANCE vs. OUTPUT VOLTAGE
ON-RESISTANCE vs. OUTPUT VOLTAGE
ON-RESISTANCE vs. OUTPUT VOLTAGE
(SINGLE SUPPLY)
(DUAL SUPPLIES)
AND TEMPERATURE (DUAL SUPPLIES)
250
140
120
100
80
V+ = +15V
V- = -15V
V- = 0V
V+ = +8V
V- = -8V
V+ = +9V
V+ = +10V
V- = -10V
120
100
80
60
40
20
0
200
150
100
50
T
= +125°C
= +85°C
A
T
A
V+ = +12V
V+ = +15V
V- = -15V
T
= +70°C
A
60
T
A
= +25°C
V+ = +20V
T
= -40°C
A
40
V+ = +30V
T
A
= -55°C
V+ = +18V
V- = -18V
20
0
V+ = +36V
25
0
-20 -15 -10 -5
0
5
10 15 20
0
5
10
15
V
20
30
35
-15
-10
-5
0
5
10
15
V
OUT_
(V)
(V)
V
(V)
OUT_
OUT_
ON-RESISTANCE vs. OUTPUT VOLTAGE
AND TEMPERATURE (SINGLE SUPPLY)
OUTPUT CLAMP CURRENT SUPPLIES ON
vs. TEMPERATURE
OUTPUT CLAMP RESISTANCE SUPPLIES ON
250
200
150
100
50
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
25
20
15
10
5
V+ = +12V
V- = 0
V+ = +15V
V- = -15V
IN
V+ = +15V
V- = -15V
V
= ±25V
T
= +125°C
= +85°C
A
V
IN
= +25V
T
A
T
= +70°C
A
0
V
IN
= -25V
T
A
= +25°C
T
T
= -40°C
= -55°C
-5
A
-10
-15
-20
-25
A
0
0
2
4
6
8
10
12
-55 -35 -15 -5 25 45 65 85 105 125
-55 -40 -25 -10
5
20 35 50 65 80 95 110 125
V
OUT_
(V)
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT TRANSFER CHARACTERISTICS
(DUAL SUPPLIES)
OUTPUT TRANSFER CHARACTERISTICS
(SINGLE SUPPLY)
FAULT-FREE ANALOG SIGNAL RANGE
vs. SUPPLY VOLTAGE
20
15
10
5
40
35
30
25
20
15
10
5
20
15
10
5
(V+ = +18V, V- = -18V)
(V+ = +15V, V- = -15V)
OUTPUT LOAD = 1MΩ
V+ = +36V
V- = 0
(V+ = +10V, V- = -10V)
(V+ = +8V, V- = -8V)
V+ = +25V
INPUT VOLTAGE
LINEARLY SWEPT
BETWEEN -30V
0
0
V+ = +15V
-5 AND +30V
-5
(V+ = +8V, V- = -8V)
(V+ = +10V, V- = -10V)
(V+ = +15V, V- = -15V)
(V+ = +18V, V- = -18V)
V+ = +12V
V+ = +9V
-10
-15
-20
-10
-15
-20
INPUT VOLTAGE LINEARLY SWEPT
BETWEEN 0 AND 35V
OUTPUT LOAD = 1MΩ
-30 -20 -10
INPUT VOLTAGE (V)
0
0
10
20
30
0
5
10 15 20 25 30 35 40
INPUT VOLTAGE (V)
-20 -15 -10 -5
0
5
10 15 20
INPUT VOLTAGE (V)
_______________________________________________________________________________________
5
Fault-Protected, High-Voltage
Signal-Line Protectors
Typical Operating Characteristics (continued)
(T = +25°C, unless otherwise noted.)
A
MAX4506
POWER-SUPPLY CURRENT
vs. TEMPERATURE
FAULT-FREE OUTPUT LEAKAGE CURRENT
INPUT FAULT LEAKAGE CURRENT
WITH SUPPLIES ON
WITH SUPPLIES ON
100n
150
125
100
75
1µ
100n
10n
1n
V
OUT
= ±10υ
V+ = +15V
V- = -15V
10n
1n
I+
I
(V+ = +15V, V- = -15V)
I
AT +25V (V+ = +15V, V- = -15V)
OUT
IN
50
25
0
I+ SINGLE SUPPLY +12V
100p
10p
I
(V+ = +12V, V- = 0)
OUT
100p
10p
1p
-25
-50
-75
-100
-125
-150
1p
I
AT +25V (V+ = +12V, V - = 0)
25 45 65 85 105 125
IN
5
I-
0.1p
0.01p
0.1p
-55 -30 -5 20 45 70 95 120 145
-55 -35 -15
5
25 45 65 85 105 125
-55 -35 -15
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
6/MAX4507
MAX4507
POWER-SUPPLY CURRENT vs.
TEMPERATURE
SUPPLY CURRENT vs.
INPUT VOLTAGE
FREQUENCY RESPONSE
10
100
80
250
200
150
100
50
V+ = +15V
I+
BANDWIDTH
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
V- = -15V
I+
60
40
V+ = +15V
V- = -15V
20
I+ SINGLE SUPPLY + 12V
0
0
CROSSTALK
-20
-40
-60
-80
-100
-50
-100
-150
-200
-250
I-
I-
0.01
0.1
1
10
100
1000
-15
10
5
0
5
10
15
-55 -35 -15
5
25 45 65 85 105 125
FREQUENCY (MHz)
INPUT VOLTAGE (V)
TEMPERATURE (°C)
INPUT OVERVOLTAGE
vs. OUTPUT CLAMPING
FAULT-FREE SIGNAL PERFORMANCE
FAULT RECOVERY
MAX45506/07 toc16
MAX45506/07 toc17
MAX45506/07 toc18
+25V
+15V
+16V
+15V
IN_
IN_
IN_
0V
10V/div
5V/div
-15V
+15V
0V
+15V
OUT_
OUT_
0V
10V/div
-25V
5V/div
0V
0V
OUT_
V+ = +15V
V- = -15V
0V
-15V
-15V
5µs/div
5µs/div
5µs/div
±25V OVERVOLTAGE INPUT WITH THE OUTPUT
CLAMPED AT ±15V
FAULT-FREE RAIL-TO-RAIL SIGNAL HANDLING
WITH ±15V SUPPLIES
6
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
Pin Description
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
5–9
IN1, IN2, IN3
Signal Inputs 1, 2, 3
–
4–8
IN4, IN5, IN6, IN7, IN8
Signal Inputs 4, 5, 6, 7, 8
4
9
10–14
15, 16, 17
18
10
V-
Negative Supply Voltage Input
Signal Outputs 8, 7, 6, 5, 4
Signal Outputs 3, 2, 1
–
11–15
16, 17, 19
20
OUT8, OUT7, OUT6, OUT5, OUT4
5, 6, 7
OUT3, OUT2, OUT1
8
–
V+
Positive Supply-Voltage Input
No Connection. Not internally connected.
–
3, 18
N.C.
* Connect all unused inputs to a hard voltage within the supply range (e.g., V+, V-, or GND).
Detailed Description
-15V
COMPARATOR
The MAX4506/MAX4507 protect other ICs from over-
voltage 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/
N-CHANNEL
DRIVER
-V(-15V)
CLAMP
MAX4507 provide protection for input signals up to
-15V
N3
±36V with the power supplies on and ±40V with the
power supplies off.
SENSE
SWITCH
N2
The MAX4506/MAX4507 protect other integrated cir-
cuits 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 cir-
cuit draws excessive current and may continue to draw
excessive current even after the overvoltage condition
is removed. A continuous latchup condition may dam-
age the device permanently. Such “faults” are com-
monly 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, start-
up, or a power failure.
N1
IN
OUT
CLAMP P2
+V(+15V)
P1
P3
SENSE
SWITCH
P-CHANNEL
DRIVER
+15V
COMPARATOR
+15V
Figure 1. Simplified Internal Structure
Figure 1 shows the normal complementary pair (N1 and
P1) found in many common analog switches. In addi-
tion 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-
tion, N1 and P1 remain on with a typical 65Ω on-resis-
tance between IN and OUT.
The on-board comparators and sensing circuitry moni-
tor the input voltage for possible overvoltage faults.
_______________________________________________________________________________________
7
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.
MAX4506
Normal Operation
When power is applied, each protector acts as a resis-
4
1
8
tor 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).
V-
V-
V+
V+
R
IN1
OUT1
7
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).
V
IN
OUT
Figure 2. Application Circuit
Fault Protection, Power Off
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.
6/MAX4507
+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.
MAX4506
8
V+
10µF
100k
IN1
IN2
OUT1
OUT2
OUT3
1
2
7
6
5
Applications Information
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 V-
pin 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.
OP AMP
IN3
V-
3
4
100k
10µF
-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 sup-
ply enough current to maintain the load voltage at the
supply rail in a fault condition.
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
_______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
Use the MAX4506 with a MAX338 to enhance voltage
handling capability (Figure 6). The MAX4506 and
MAX338 share almost equal voltage drops in this con-
figuration. 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 volt-
age drops.
Protectors as Circuit Elements
Each of the protectors in a MAX4506/MAX4507 may be
used as a switched resistor, independent of the func-
tions of other elements in the same package. For exam-
ple, 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.
Figure 5 shows MAX4506 used in front of a MAX338
unprotected 1-to-8 multiplexer. With supplies at ±15V,
V
of the MAX4506 clamps to ±15V; V
of the
OUT
OUT
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 sig-
nals (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.
MAX338 goes to ±14V. With supplies off, V
goes to
OUT
0V while the inputs remain at ±25V.
SWITCHED +15V
P
+15V
MAX4506
8
V+
IN1
IN2
OUT1
OUT2
OUT3
1
2
7
6
5
100k
V
OUT
= -14V
10k
+40V
-40V
OP AMP
1
2
7
6
4
5
8
IN3
V-
3
4
MAX4506
MAX338
-15V
Figure 4. Power-Supply Sequencing
Figure 6. SPDT Switch Application
+3V
+3V
O
1
A
A1 16
A2 15
O
OV
1
2
3
4
5
6
7
8
A
A1 16
A2 15
O
+5V
-5V
2
3
4
5
6
7
8
EN
V-
+5V
EN
V-
GND
GND
14
NEW COM
-15V
14
+25V
-25V
1
2
3
4
8 +15V
NO1 MAX338 V+ 13 +15V
1
2
8 +15V
NO1 MAX4508 V+ 13 +15V
NO2
NO3
NO4
NO5 12
NO6 11
NO7 10
7
6
5
NO2
NO3
NO4
COM
NO5 12
NO6 11
NO7 10
7
6
5
MAX4506
MAX4506
3
-15V
-15V
4
V
OUT
NO9 9
NO9
9
R
L
Figure 7. Multiplexer and Demultiplexer Application Using
MAX4506 (or MAX4507) with MAX4508
Figure 5. Protecting a MAX338 with a MAX4506
_______________________________________________________________________________________
9
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 sys-
tem), and outputs can be taken at MAX4508 pins 4 to
7, and 9 to 12. This is the classic demultiplexer opera-
tion. This system now has full protection on both of the
multiplexers’ inputs and outputs.
Note: It is important to use a voltage source of 100mV
or less. As shown in Figure 8, this voltage and the V
IN
voltage form the V
voltage. Using higher voltages
OUT
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.
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 fol-
lowing 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-volt-
age-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 cur-
rent) for accurate results. A Keithley model 617 elec-
trometer has a suitable ammeter circuit, appropriate
ranges, and a built-in voltage source designed for this
type of measurement. Find the path resistance by set-
ting the analog voltage, measuring the current, and cal-
culating the path resistance. Repeat the procedure at
each analog and supply voltage.
Connecting a MAX4506/MAX4507 after a surge sup-
pressor 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.
6/MAX4507
+10V
MAX4506
8
V+
IN1
IN2
OUT1
OUT2
OUT3
1
2
7
6
5
A
100mV
MAX4506
V
V
8
IN1
V-
OUT1
V+
IN
OUT
OP AMP
ADJUSTABLE
IN3
V-
3
4
ANALOG
VOLTAGE
4
V+
PATH RESISTANCE = 100mv/A
SURGE SUPPRESSORS
-15V
-10V
Figure 9. Surge-Suppression Circuit
Figure 8. Path-Resistance Measuring Circuit
10 ______________________________________________________________________________________
Fault-Protected, High-Voltage
Signal-Line Protectors
6/MAX4507
Ordering Information (continued)
PART
TEMP. RANGE
0°C to +70°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
-55°C to +125°C
PIN-PACKAGE
MAX4507CAP
MAX4507CWN
MAX4507CPN
MAX4507C/D
MAX4507EAP
MAX4507EWN
MAX4507EPN
MAX4507MJN
20 SSOP
18 SO
18 Plastic DIP
Dice*
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
OUT3
OUT1
IN3
IN4
IN5
IN6
IN2
0.112"
(2.84mm)
OUT4
0.112"
(2.84mm)
OUT2
OUT5
OUT6
IN3
V-
IN7
IN8
OUT3
OUT7
0.071"
(1.80mm)
V-
OUT8
0.071"
(1.800mm)
TRANSISTOR COUNT:
144 (MAX4506)
379 (MAX4507)
SUBSTRATE CONNECTED TO V+
______________________________________________________________________________________ 11
Fault-Protected, High-Voltage
Signal-Line Protectors
Pin Configurations (continued)
TOP VIEW
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
V-
1
2
3
4
5
6
7
8
9
18 V+
IN1
IN2
N.C.
IN3
IN4
IN5
IN6
IN7
IN8
1
2
3
4
5
6
7
8
9
20 V+
19 OUT1
18 N.C.
17 OUT2
16 OUT3
15 OUT4
14 OUT5
13 OUT6
12 OUT7
11 OUT8
17 OUT1
16 OUT2
15 OUT3
14 OUT4
13 OUT5
12 OUT6
11 OUT7
10 OUT8
MAX4507
MAX4507
V- 10
6/MAX4507
SO/DIP
SSOP
Package Information
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.
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