MAX4506C View Datasheet(PDF) - Maxim Integrated
Part Name
Description
Manufacturer
MAX4506C Datasheet PDF : 12 Pages
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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
When power is applied, each protector acts as a resis-
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).
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
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.
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
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.
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
MAX4506
V-
4 V-
V+ 8
V+
1 IN1
VIN
OUT1 7
ROUT
Figure 2. Application Circuit
+15V
1 IN1
MAX4506
V+ 8
10µF
OUT1 7
100kΩ
2 IN2
3 IN3
4 V-
OUT2 6
OUT3 5
OP AMP
10µF
100kΩ
-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.
8 _______________________________________________________________________________________
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