Fault Windows Scaled Independently

Fault window for the Sense Input,

in percent, is:

,

for:

=2.5V

Monitored

SupplyVoltage

R1

R2

R3

UC1903

SENSE1-4INPUT

2.5V

REF.

Fault window for the sense input, in percent, is:

•

SENSE

INPUT

R1

R2

UC1903

G.P.OP-AMP

2.5V

REF.

SENSE1-4INPUT

±10(V

)

ADJ

UC1903

UC2903

UC3903

In many applications, it may be desirable to monitor various supply voltages, or voltage levels, with varying fault

windows. Using the reference output and external resistive dividers this is easily accomplished with the UC1903.

Figure 3 and Figure 4 illustrate how the fault window at any sense input can be scaled independently of the

remaining inputs.

A.

Using the reference output and a resistive divider, a sense input with an independently wider fault window can be

generated.

Figure 3. UC1903 Sense Input with an Independently Wider Fault Window

A.

The general purpose op-amp on the UC1903 can be used to create a sense input with an independently tighter fault

window.

Figure 4. UC1903 Sense Input with an Independently Tighter Fault Window

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Product Folder Link(s): UC1903 UC2903 UC3903