3.0V/3.3V Microprocessor Supervisory Circuits

10

______________________________________________________________________________________

MAX690T/S/R

MAX704T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

MAX806T/S/R

GND

0V

TO

µP

PFI

PFO

*OPTIONAL

C1*

PFO

0V

+

1

+

1

1

–

WHERE

GND

TO

µP

PFI

PFO

*OPTIONAL

C1*

+

1

+

1

1

–

WHERE

MAX690T/S/R

MAX704T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

MAX806T/S/R

0V

PFO

0V

b

a

(

)

(

)

(

)

(

)

+

1

+

1

1

(

)

MAX690T/S/R

MAX704T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

MAX806T/S/R

GND

PFI

PFO

V-

0V

V-

PFO

WHERE

3.0V OR 3.3V

+

1

)

(

1

–

+

1

)

(

1

–

MAX690T/S/R

MAX704T/S/R

MAX802T/S/R

MAX804T/S/R

MAX805T/S/R

MAX806T/S/R

GND

PFI

PFO

PFO

* MAX704T/S/R,

MAX806T/S/R ONLY

3.0V OR 3.3V

)

(

MR

*

b

a

)

(

Figure 4. a) Adding Additional Hysteresis to the Power-Fail Comparator

Figure 5. Using the Power-Fail Comparator to Monitor an Additional Power Supply