Data Sheet

ADCMP391/ADCMP392/ADCMP393

Rev. D | Page 11 of 17

TYPICAL APPLICATIONS

ADDING HYSTERESIS

To add hysteresis, see Figure 28; two resistors are used to create

different switching thresholds, depending on whether the input

signal is increasing or decreasing in magnitude. When the input

OUTx

INx–

INx+

R1

R2

Figure 28. Noninverting Comparator Configuration with Hysteresis

The upper input threshold level is given by

R2

R2

R1

V

V

REF

IN_HI

)

( +

=

(2)

The lower input threshold level is given by

(

)

PULLUP

CC

PULLUP

REF

LO

IN

R

R2

R1

V

R

R2

R1

V

V

+

−

+

+

=

_

(3)

The hysteresis is the difference between these voltages levels.

)

(

UP

PULL

CC

UP

PULL

REF

HYS

R

R2

R2

R1R2

V

R1R

V

V

−

−

+

+

=

(4)

WINDOW COMPARATOR FOR POSITIVE VOLTAGE

MONITORING

When monitoring a positive supply, the desired nominal

OUTA

INA+

INA–

OUTB

INB+

INB–

Figure 29. Positive Undervoltage/Overvoltage Monitoring Configuration

Figure 29 illustrates the positive voltage monitoring input

connected to the INA+ pin and the low-side voltage is

connected to the INB− pin.

To trigger an overvoltage condition, the low-side voltage (in this













+

+

=

=

Z

Y

X

Z

OV

REF

PL

R

R

R

R

V

V

V

(5)

In addition,

(6)

overvoltage monitor, is calculated as

(

)( )

(

M

OV

M

REF

Z

I

V

V

V

R =

(7)

To trigger the undervoltage condition, the high-side voltage,













+

+

+

=

=

Z

Y

X

Z

Y

UV

REF

PH

R

R

R

R

R

V

V

V

(8)

(

)( )

(

)( )

Z

M

UV

M

REF

Y

R

I

V

V

V

R

−

=

(9)

(10)