ADG5436F datasheet(28/30 Pages) AD

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ADG5436F

Data Sheet

Rev. B | Page 28 of 30

APPLICATIONS INFORMATION

The overvoltage protected family of switches and multiplexers

provide a robust solution for instrumentation, industrial,

aerospace, and other harsh environments where overvoltage

signals can be present and the system must remain operational

both during and after the overvoltage has occurred.

POWER SUPPLY RAILS

To guarantee correct operation of the device, 0.1 µF decoupling

capacitors are required.

The ADG5436F can operate with bipolar supplies between ±5 V

and ±22 V. The supplies on VDD and VSS do not need to be

symmetrical, but the VDD to VSS range must not exceed 44 V.

The ADG5436F can also operate with single supplies between

8 V and 44 V, with VSS connected to GND.

The ADG5436F is fully specified at the ±15 V, ±20 V, 12 V, and

+36 V supply ranges.

POWER SUPPLY SEQUENCING PROTECTION

The switch channel remains open when the device is

unpowered and signals from −55 V to +55 V can be applied

without damaging the device. The switch channel closes only

when the supplies are connected, a suitable digital control signal

is placed on the INx pins, and the signal is within the normal

operating range. Placing the ADG5436F between external

connectors and sensitive components offers protection in systems

where a signal is presented to the source pins before the supply

voltages are available.

SIGNAL RANGE

The ADG5436F has overvoltage detection circuitry on the

inputs that compares the voltage levels at the source terminals

with VDD and VSS. To protect downstream circuitry from

overvoltage conditions, supply the ADG5436F with voltages

that match the intended signal range. The low on-resistance

switch allows signals to the supply rails to be passed with very

little distortion. A signal that exceeds the supply rail by the

threshold voltage is then blocked. This signal block offers

protection to both the device and any downstream circuitry.

LOW IMPEDANCE CHANNEL PROTECTION

The ADG5436F can be used as a protective element in signal

chains that are sensitive to both channel impedance and

overvoltage signals. Traditionally, series resistors limit the

current during an overvoltage condition to protect susceptible

components.

These series resistors affect the performance of the signal chain

and reduce the signal chain precision. A compromise must be

reached on the value of the series resistance that is high enough

to sufficiently protect sensitive components, but low enough

that the precision performance of the signal chain is not

sacrificed.

The ADG5436F enables the designer to remove these resistors

and retain precision performance without compromising the

protection of the circuit.

POWER SUPPLY RECOMMENDATIONS

Analog Devices, Inc., has a wide range of power management

products to meet the requirements of most high performance

signal chains.

An example of a bipolar power solution is shown in Figure 51.

The ADP7118 and ADP7182 can be used to generate clean positive

and negative rails from the dual switching regulator output. These

rails can be used to power the ADG5436F, amplifier, and/or

precision converter in a typical signal chain.

Figure 51. Bipolar Power Solution

Table 10. Recommended Power Management Devices

Product

Description

ADP7118

20 V, 200 mA, low noise, CMOS LDO

ADP7142

40 V, 200 mA, low noise, CMOS LDO

ADP7182

−28 V, −200 mA, low noise, linear regulator

HIGH VOLTAGE SURGE SUPPRESSION

The ADG5436F is not intended for use in very high voltage

applications. The maximum operating voltage of the transistor

is 80 V. In applications where the inputs are likely to be subject

to overvoltage conditions exceeding the breakdown voltage, use

transient voltage suppressors (TVSs) or similar devices.

LDO

+15V

–15V

12V

INPUT

ADP7182

LDO

DUAL

SWITCHING

REGULATOR

ADP7118

+16V

–16V

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