Datasheet

(All grades, T
A
= +25°C, unless otherwise noted.) (Note 10)
(V
CC
= 4.0V to 5.5V, all grades, T
A
= +25°C, unless otherwise noted.)
Note 1: All voltages referenced to ground.
Note 2: Trip-point voltage for power-fail detect: V
TP
= 1.26 x V
BATT
. For 5% operation: V
BATT
= 3.7V max.
Note 3: 50pF load capacity.
Note 4: Measured with pins 3, 11, 12, 13, and open.
Note 5: V
TP
is the point at which PF is driven low.
Note 6: V
BATTF
is the point at which BF is driven low.
Note 7: I
CCO2
may be limited by battery capacity.
Note 8: Battery leakage is the internal energy consumed by the MAX1259.
Note 9: See the Typical Operating Characteristics BAT Switch Drop vs. Battery Voltage graph.
Note 10: Guaranteed by design. Not tested.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Capacitance C
IN
5 10 pF
Output Capacitance C
OUT
5 10 pF
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V
CCI
Fall Time t
F
300 µs
V
CCI
Rise Time t
R
1 µs
Power-Down to PF Low
t
PF
0 µs
PF High After Power-Up
t
REC
100 µs
RST Pulse Width RST
PW
50 10 ns
PIN NAME FUNCTION
1, 4, 9, 10, 14 N.C. No Connection. Make no connection to these pins.
2 V
BATT
Backup Battery Input
3
BF
Battery-Fail Output. BF is high for V
CCI
at or above V
TP
and the backup battery greater than 2V. If the
backup battery is below 2V or V
CCI
falls below V
TP
, BF will be driven low.
5 BAT
Battery Output. During normal operation, the BAT output supplies up to 1mA of continuous battery
current. In shipping mode, the BAT output is high impedance.
6 RST
Battery-Disconnect Input. The RST input is used to prevent battery discharge during shipping. Pulsing
the RST input disconnects the backup battery from the V
CCO
and BAT outputs.
7, 8 GND Ground
11
PF Power-Fail Output. PF is high for V
CCI
greater than 1.26 x V
BATT
(V
TP
), indicating a valid V
CCI
voltage.
12, 13 V
CCO
CMOS RAM is Powered from V
CCO
. The battery switchover circuit compares V
CCI
to the V
BATT
input,
and connects V
CCO
to whichever is higher.
15, 16 V
CCI
+5V V
CC
Input
MAX1259 Battery Manager
www.maximintegrated.com
Maxim Integrated │ 3
Capacitance
Pin Description
AC Electrical Characteristics