MAX805RC/D Maxim Integrated, MAX805RC/D Datasheet - Page 10
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MAX805RC/D
Manufacturer Part Number
MAX805RC/D
Description
Supervisory Circuits
Manufacturer
Maxim Integrated
Series
MAX690R, MAX690S, MAX690T, MAX704R, MAX704S, MAX704T, MAX802, MAX802R, MAX802S, MAX802T, MAX804, MAX804R, MAX804S, MAX804T, MAX805, MAX805R, MAX805S, MAX805T, MAX806, MAX806R, MAX806S, MAX806Tr
Datasheet
1.MAX805TEPA.pdf
(12 pages)
Specifications of MAX805RC/D
Number Of Voltages Monitored
1
Monitored Voltage
4.65 V
Output Type
Active High, Push-Pull
Manual Reset
Not Resettable
Watchdog
Watchdog
Battery Backup Switching
Backup
Supply Voltage - Max
5.5 V
Chip Enable Signals
No
Power Fail Detection
Yes
Supply Voltage - Min
1.1 V
3.0V/3.3V Microprocessor Supervisory Circuits
Figure 4. a) Adding Additional Hysteresis to the Power-Fail Comparator
Figure 5. Using the Power-Fail Comparator to Monitor an Additional Power Supply
10
a
a
______________________________________________________________________________________
PFO
V
V
TRIP
CC
V
L
PFO
= R
= R
R
R
R
R
V
0V
V
2
2
V
1
2
1
2
TRIP
H
L
V
(V
= (V
(V
V-
= R
0V
IN
PFT
PFT
= V
1
PFT
PFT
+ V
)
V
(
PFT
+ V
PFH
1
R
(
1
R
PFH
C1*
1
+
)
(
R
+ R
(
1
R
) (R
2
1
R
TO μP
1
1
R
2
2
+
1
1
)
)
)
+
1
R
–
R
(
PFI
2
3
R
1
R
1
V
+
2
1
CC
R
V
V
L
1
+
L
)
1
R
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
PFI
PFO
–
3
1
R
)
2
V
V
CC
TRIP
R
–
V
+
V
GND
1
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
TRIP
CC
V
1
R
CC
R
3
3
3.0V OR 3.3V
)
GND
V
CC
V
WHERE
H
WHERE
NOTE: V
PFO
0V
V
V
PFT
PFH
TRIP
V
V
*OPTIONAL
PFT
PFH
= 1.237V
= 10mV
IS NEGATIVE
= 1.237V
= 10mV
V
IN
V-
b
b
b) Shifting the Additional Hysteresis above V
PFO
V
CC
V
V
TRIP
H
= (V
PFO
V
R
R
V
=
1
2
TRIP
WHERE
R
R
H
PFT
0V
1
2
V
V
= R
PFT
IN
V
= V
+ V
0V
IN
1
PFT
(
(V
V
V
PFH
R
PFT
PFH
PFT
1
V
V
R
D
(
L
+ R
)
R
2
(
+ V
1
= 1.237V
= DIODE FORWARD VOLTAGE DROP
= V
= 10mV
2
R
R
+ R
C1*
1
2
TRIP
)
PFH
R
+ R
2
2
TO μP
)
)
2
V
(
PFI
TRIP
)
R
1
R
3
1
V
+
TRIP
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
PFI
PFO
1
R
V
2
H
+
V
GND
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
CC
1
R
3
3.0V OR 3.3V
)
GND
V
–
CC
V
(V
H
* MAX704T/S/R,
CC -
MAX806T/S/R ONLY
PFO
MR
R
3
V
D
PFT
)
*OPTIONAL
*
V
V
IN
IN