MITSUMI
Protection of Lithium Ion Batteries (four cells in series) MM1294
Protection of Lithium Ion Batteries (four cells in series)
Monolithic IC MM1294
Outline
This IC provides protection for lithium ion batteries in the event of overcharging, overdischarging and
overcurrents. When anomalies occur during charging or at other times and excessive voltages are applied,
after a certain time has elapsed for each cell an external FET switch is turned off (overcharging detection); and
in order to prevent overdischarge of the battery during discharge, when the voltage of individual batteries falls
below a fixed voltage, an external FET switch is turned off (overdischarge detection), and the IC is put into
low-consumption current mode. When large currents flow due to a short-circuit or other cause, an external
MOS switch is turned off (overcurrent detection).
4-Cell Protection ICs
Rank
A
B
C
Overcurrent
Overcharge Overcharge Overdischarge Overdischarge Overcurrent At overcurrent
detection voltage hysteresis voltage detection voltage resume voltage detection voltage
detection
release conditions
Load release
4.35V鹵50mV 200mV typ. 2.35V typ. 3.05V typ.
150mV typ. Pin 3 (DOHG pin) L H
300k鈩?or more
4.25V鹵50mV
2.40V typ. 3.10V typ.
Same as rank A 200mV typ.
Same as rank A
Charging reset
Features
1. Current consumption (overcharging)
V
CELL
> V
CELLU
170碌A(chǔ) typ.
2. Current consumption (normal operation)
V
CELL
< V
ALM
35碌A(chǔ) typ.
3. Current consumption (overdischarge)
V
CELL
< V
CELLS
0.1碌A(chǔ) max.
4. Overcharge detection voltage (-20 to +70擄C) V
CELL
: L H
4.25V鹵50mV/CELL
5. Overcharge hystereis voltage
V
CELL
: H L
V
CELLU
-200mV/CELL typ.
6. Overcharge sensing dead time
C=0.1碌F
1.0S typ.
7. Overcharge sensing operation voltage
V
CELL
: L H
4.10V鹵150mV/CELL
8. Overdischarge detection voltage
V
CELL
: H L
2.40V/CELL typ.
9. Overdischarge sensing dead time
C=0.1碌F
1.0S typ.
10.Overcurrent detection voltage
0.15V typ.
11.Overcharge and overdischarve voltages as well as the overcurrent detection voltage can be changed upon
request.
Package
SSOP-16
Applications
Lithium ion battery pack for notebook computers
MITSUMI
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