Datasheet

Figure 8. (a) Adding Additional Hysteresis to the Power-Fail Comparator. (b) Shifting the Additional Hysteresis above V
TRIP
GND
TO µP
PFI
R2
C1 C1
R3 R3
R1
PFO (PUSH-PULL)
MAX16033
MAX16040
V
CC
V
IN
PFO
GND
TO µP
PFI
R2
R1
PFO (PUSH-PULL)
MAX16033
MAX16040
V
CC
V
IN
0V
V
L
V
H
V
H
V
IN
V
TRIP
V
TRIP
PFO
0V
V
IN
(a) (b)
TRIP PFT
H PFT PFH
L PFT CC
PFT
PFH
R1
V V 1
R2
R1 R1
V (V V )1
R2 R3
R1 R1 R1
V V 1 V
R2 R3 R3
V 1.235V
V 12mV

= +



= + ++



= ++ −


=
=
TRIP PFT
H PFT PFH D
L TRIP
PFT
PFH
D
R1
V V 1
R2
R1 R1 R1
V (V V )1 V
R2 R3 R3
V V
V 1.235V
V 12mV
V DIODE FORWARD VOLTAGE

= +



= + ++ −


=
=
=
=
MAX16033–MAX16040 Low-Power Battery-Backup
Circuits in Small μDFN Packages
www.maximintegrated.com
Maxim Integrated │ 14