Rainbow Electronics MAX16024 - Manual (Page 14)

MAX16023/MAX16024
Operation Without a Backup
Power Source
The MAX16023/MAX16024 provide battery-backup
functions. If a backup power source is not used, con-
nect BATT to GND.
Replacing the Backup Battery
When V CC is above V TH , the backup power source can
be removed without danger of triggering a reset pulse.
The device does not enter battery-backup mode when
V
CC stays above the reset threshold voltage.
Negative-Going V CC Transients
The MAX16023/MAX16024 are relatively immune to
short duration, negative-going V
CC transients.
Resetting the µP when V CC experiences only small
glitches is usually not desirable. A 0.1µF bypass
capacitor mounted close to the V
CC pin provides addi-
tional transient immunity.
Capacitor Selection and
Regulator Stability
For stable operation, connect a low-ESR 10µF (min) out-
put capacitor from OUT to GND. To reduce noise and
improve load-transient response and power-supply rejec-
tion, use larger output capacitor values.
Battery-Backup Circuits with
Regulated Output Voltage
14 ______________________________________________________________________________________
MAX16023
0.1 μF
GND
PFI
PFO
R2
R1
R3
V CC
V H =
(
V PFT + V PFT - HYS
)
x
(
+ + 1
) R1
R2 R1
R3
V L = R1 x
(
-
)
+ V PFT
V PFT
R2
V CC - V PFT
R3
WHERE V PFT IS THE POWER-FAIL
THRESHOLD VOLTAGE.
*OPTIONAL
+5V
V IN
C1*
TO μP
PFO
0
+5V
V TRIP V L V H V IN
V TRIP = V PFT x
( ) R1 + R2
R2
Figure 5. Adding Hysteresis to the Power-Fail Comparator
Part Number Table
PART
OUTPUT
TYPE
R ESET
T H R ESH O L D
VO L T A G E
( V)
REGUL ATED
OU TPU T
VO LTA GE
( V)
PART
OUTPUT
TYPE
R ESET
T H R ESH O L D
VO L T A G E
( V)
R EG U L A T ED
O U T PU T
VO L T A G E
( V)
MAX16023LTAL12+T Push-Pull 4.63 1.2 MAX16024LTBL12+T Push-Pull 4.63 1.2
MAX16023LTAL18+T Push-Pull 4.63 1.8 MAX16024LTBL18+T Push-Pull 4.63 1.8
MAX16023LTAL25+T Push-Pull 4.63 2.5 MAX16024LTBL25+T Push-Pull 4.63 2.5
MAX16023LTAL33+T Push-Pull 4.63 3.3 MAX16024LTBL33+T Push-Pull 4.63 3.3
MAX16023LTAM12+T Push-Pull 4.38 1.2 MAX16024LTBM12+T Push-Pull 4.38 1.2
MAX16023LTAM18+T Push-Pull 4.38 1.8 MAX16024LTBM18+T Push-Pull 4.38 1.8
MAX16023LTAM25+T Push-Pull 4.38 2.5 MAX16024LTBM25+T Push-Pull 4.38 2.5
MAX16023LTAM33+T Push-Pull 4.38 3.3 MAX16024LTBM33+T Push-Pull 4.38 3.3
MAX16023LTAT12+T Push-Pull 3.08 1.2 MAX16024LTBT12+T Push-Pull 3.08 1.2
MAX16023LTAT18+T Push-Pull 3.08 1.8 MAX16024LTBT18+T Push-Pull 3.08 1.8
MAX16023LTAT25+T Push-Pull 3.08 2.5 MAX16024LTBT25+T Push-Pull 3.08 2.5
MAX16023LTAS12+T Push-Pull 2.93 1.2 MAX16024LTBS12+T Push-Pull 2.93 1.2
MAX16023LTAS18+T Push-Pull 2.93 1.8 MAX16024LTBS18+T Push-Pull 2.93 1.8
MAX16023LTAS25+T Push-Pull 2.93 2.5 MAX16024LTBS25+T Push-Pull 2.93 2.5
MAX16023LTAR12+T Push-Pull 2.63 1.2 MAX16024LTBR12+T Push-Pull 2.63 1.2
MAX16023LTAR18+T Push-Pull 2.63 1.8 MAX16024LTBR18+T Push-Pull 2.63 1.8
MAX16023LTAR25+T Push-Pull 2.63 2.5 MAX16024LTBR25+T Push-Pull 2.63 2.5
MAX16023LTAZ12+T Push-Pull 2.32 1.2 MAX16024LTBZ12+T Push-Pull 2.32 1.2