ADG5462F datasheet(28/29 Pages) AD

28 / 29 page

ADG5462F

Data Sheet

Rev. B | Page 28 of 29

INTELLIGENT FAULT DETECTION

The ADG5462F digital output pin (FF) can interface with a

microprocessor or control system and be used as an interrupt

flag. This feature provides real-time diagnostic information on

the state of the device and the system to which it connects.

The control system can use the digital interrupt to start a

variety of actions, such as

•

Initiating investigation into the source of the overvoltage fault

•

Shutting down critical systems in response to the overvoltage

•

Signaling the data recorders to mark data during these

events as unreliable or out of specification

For systems that are sensitive during a start-up sequence, the

active low operation of the flag allows the system to ensure that

the ADG5462F is powered on and that all input voltages are

within normal operating range before initiating operation.

The FF pin is a weak pull-up, which allows the signals to be

combined into a single interrupt for larger modules that contain

multiple devices.

The interrupt flag recovery time, tDIGREC, can be decreased from

a typical 60 µs to 600 ns by using a 1 kΩ pull-up resistor.

The DR pin can also be used for diagnostic purposes. The FF

pin provides an interrupt that indicates one of the four channels

has a fault. The DR pin can then be pulled low to find which of

the channels has a fault as well as the polarity of the fault. For

example, if an ADC downstream is monitoring the channel, a

full-scale reading then indicates a positive fault, and a zero-scale

reading indicates a negative fault.

LARGE VOLTAGE, HIGH FREQUENCY SIGNALS

Figure 24 illustrates the voltage range and frequencies that the

ADG5462F can reliably convey. For signals that extend across

the full signal range from VSS to VDD, keep the frequency less

than 3 MHz. If the required frequency is greater than 3 MHz,

decrease the signal range appropriately to ensure signal integrity.

ADG5462F Datasheet(PDF) 28 Page - Analog Devices