MITSUMI
Protection of Lithium Ion Batteries (three cells in series) MM1293
Protection of Lithium Ion Batteries (three cells in series)
Monolithic IC MM1293
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 (overdischarging 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).
Package
SSOP-16
Features
1. Current consumption (overcharging)
V
CELL
> V
CELLU
125A typ.
2. Current consumption (normal operation)
V
CELL
< V
ALM
30A typ.
3. Current consumption (overdischarge)
V
CELL
< V
CELLS
0.1A max.
4. Overcharge sensing dead time
C=0.1F
1.0S typ.
5. Overcharge sensing operation voltage
V
CELL
: L H
A, G; 4.20V150mV/CELL
B; 4.10V150mV/CELL
6. Overdischarge sensing dead time
C=0.1F
1.0S typ.
7. Overcurrent detection voltage
0.15V typ.
8. Overcurrent protection circuit
A, B; Load open 250k
or higher
G; charging reset
9. Overcharge and overdischarve voltages as well as the overcurrent detection voltage can be changed upon
request.
Applications
Lithium ion battery pack for notebook computers
3-Cell Protection ICs
Temperature conditions A: Ta=-25 ~ 75C, B: Ta=-20 ~ 70C, C: Ta=0 ~ 50C,
D: Ta=0 ~ 40C, E: Ta=-20 ~ 25C
Model
Package
SSOP-16
AJ
4.3500.050
B
20060
2.350.10
3.050.15
15015
MM1293
BJ
4.2500.050
B
20060
2.400.10
3.100.15
15015
GJ
4.3500.050
B
20060
2.350.10
3.050.15
15015
Overcharge
detection
voltage (V)
Overcharge
detection voltage
temperature
conditions
Overcharge
detection
hysteresis
voltage (V)
Overdischarge
detection
voltage (V)
Overdischarge
reset
voltage (V)
Overcurrent
detection
voltage (mV)
MITSUMI
Protection of Lithium Ion Batteries (three cells in series) MM1293
Block Diagram
Pin Assignment
SSOP-16
1
3
7
6
2
4 5
8
16
13
11
15 14
12
9
10
1
OV
9
GND
2
CS
10
ML
3
DCHG
11
BATL
4
PF
12
MM
5
CDC
13
BATM
6
COL
14
MH
7
COV
15
BATH
8
MSW
16
V
CC
MITSUMI
Protection of Lithium Ion Batteries (three cells in series) MM1293
Pin Assignment
Pin no.
Pin name
Input/output
Function
1
OV
Output
Overcharge detection output pin
NPN transistor open collector output; normally high impedance, goes to L
level on overdischarge
Overcurrent detection pin
Monitors equivalent load current through source-drain voltage drop of discharge-controlling
FET, and at or above the overcurrent detection voltage sets the DCHG pin to "H" and turns
off the discharge-controlling FET. Following overcurrent detection, current is passed from
this pin, and if the load is decreased, the overcurrent mode is canceled. Through this action
there is a temporary consumption current (at the V
CC
pin) of approx. 1 mA on resumption of
discharge and detection of overdischarge. This function is disabled in overdischarge mode.
2
CS
Input
Pin driving the discharge-controlling FET (P-ch)
Normally "L"; on overdischarge set to "H"
Output pin for overdischarge detection signals
3
DCHG
Output
Overdischarge detection pin
When the overdischarge detector detects overdischarge at the open collector output of
the NPN transistor, this pin is turned on. A delay is provided by setting a dead time until
discharge ends, so that by utilizing a reset or other signal from a CPU or some other
controlling device, the equipment can be put into standby mode.
4
PF
Output
Pin to set the dead time for overdischarge detection
By connecting a capacitor between the CDC pin and GND, a dead time can be set.
Pin to set the dead time for overcurrent detection
5
CDC
Input
6
COL
Input
Pin to set the dead time for overcurrent detection
By connecting a capacitor between the COL pin and GND, a dead time can be
set. If NC, protection is triggered in a short amount of time; the dead time
should be set according to the application.
Pin to set the dead time for overcharge detection
By connecting a capacitor between the COV pin and GND, a dead time can be
set.
7
COV
Input
8
MSW
Input
Pin to switch the cell voltage monitor on/off
GND: monitor on, V
CC
: monitor off
The cell voltage monitor converts the different cell voltages to a GND-
reference voltage and outputs it from the ML, MM and MH pins.
9
GND
Input
Ground pin
10
ML
Output
Monitor output pin for the L cell voltage
11
BATL
Input
Pin for input of L cell high-side voltage and M cell low-side voltage
12
MM
Output
Monitor output pin for the M cell voltage
13
BATM
Input
Pin for input of M cell high-side voltage and H cell low-side voltage
14
MH
Output
Monitor output pin for the H cell voltage
15
BATH
Input
Pin for input of H cell high-side voltage
16
V
CC
Input
Power supply input pin
The same potential as the BATH pin should be input
Absolute Maximun Ratings
Item
Symbol
Ratings
Units
Storage temperature
T
STG
-40~+125
C
Operating temperature
T
OPR
-20~+70
C
Charge voltage
V
BAT
max.
18
V
Power supply voltage
V
CC
max.
18
V
Voltage applied to OV pin
V
OV
max.
18
V
Allowable loss
Pd
300
mW
MITSUMI
Protection of Lithium Ion Batteries (three cells in series) MM1293
Recommended Operating Conditions
Item
Symbol
Ratings
Units
Operating temperature
T
OPR
-20~+70
C
Operating voltage
V
OPR
+2~+18
V
Electrical Characteristics
(Except where noted otherwise, Ta=25C, V
CC
=15V, V
CELL
=V
BATH
=V
BATM
=V
BATL
) Models listed MM1293B
Item
Symbol
Measurement conditions
Min. Typ. Max. Units
Consumption current (V
CC
pin) 1
I
CC
1
V
CELL
=4.4V
125
250
A
Consumption current (V
CC
pin) 2
I
CC
2
V
CELL
=3.5V
30
60
A
Consumption current (V
CC
pin) 3
I
CC
3
V
CELL
=2.2V
0.1
A
Consumption current (BATH pin) 1
I
BATH
1
V
CELL
=4.4V
11
22
A
Consumption current (BATH pin) 2
I
BATH
2
V
CELL
=3.5V
5
10
A
Consumption current (BATH pin) 3
I
BATH
3
V
CELL
=2.2V
2
4
A
BATM pin input current 1
I
BAT
M
V
CELL
=3.5V
300
nA
BATM pin input current 2
I
BAT
MA
V
CELL
=4.4V
-0.6
-0.3
0
A
BATL pin input current 1
I
BAT
L
V
CELL
=3.5V
300
nA
BATL pin input current 2
I
BAT
LA
V
CELL
=4.4V
-0.6
-0.3
0
A
Overcharge detection voltage
V
CELL
U
Ta=-20~+70C, V
CELL
: 3.7V 4.5V
4.20
4.25
4.30
V
Overcharge detection
release voltage
V
CELL
O
V
CELL
: 4.5V 3.7V
V
Overcharge sensing dead time
t
OV
C
OV
=0.1F
0.5
1.0
1.5
s
Overcharge sensing operation voltage
V
ALM
V
CELL
: 3.5V 4.4V
3.95
4.10
4.25
V
Overdischarge sensing hysteresis voltage
V
ALM
V
CELL
: 4.4V 3.5V
120
200
300
mV
Overdischarge detection voltage
V
CELL
S
V
CELL
: 3.5V 2.0V
2.30
2.40
2.50
V
Discharge resume voltage
V
CELL
D
V
CELL
: 2.0V 3.5V
2.95
3.10
3.25
V
Overdischarge sensing hysteresis voltage
V
CS
D
V
CELL
D-V
CELL
S
490
700
910
mV
Overdischarge sensing dead time
t
CDC
1
C
CDC
=0.1F
0.5
1.0
1.5
s
Overdischarge reset dead time
t
CDC
2
C
CDC
=0.1F, V
CS
=V
CC
+0.3V
7
ms
Overcurrent detection voltage
V
OC
V
CC
-V
CS
, D
CHG
0.135 0.150 0.165
V
Overcurrent sensing dead time
t
COL
1
C
COL
=0.001F, D
CHG
5
10
15
ms
Overcurrent reset dead time
t
COL
2
C
COL
=0.001F, D
CHG
5
10
15
ms
Overcurrent sensing delay time
t
COL
3
C
COL
=0, D
CHG
150
s
Overcurrent reset delay time
t
COL
4
C
COL
=0, D
CHG
150
s
Overcurrent protection release
Open-load condition 250k
DCHG pin source current
I
SO
D
CH
V
CELL
< V
CELL
S, SW1 : A, V
DCHG
=V
CC
-1.8V
20
A
DCHG pin sync current
I
SI
D
CH
V
CELL
> V
CELL
S, SW1 : A, V
DCHG
=0.8V
20
A
DCHG pin output voltage H
V
TH
D
C
H
V
CC
-V
DCHG
, I
SO
=20A, SW1 : B
1.8
V
DCHG pin output voltage L
V
TH
D
C
L
V
DCHG
-GND, I
SI
=-20A, SW1 : B
0.8
V
OV pin sync current
I
SI
O
V
V
OV
=0.4V, Ta=-20~+70C
0.2
mA
PF pin sync current
I
SI
P
F
V
PF
=0.4V, Ta=-20~+70C
10
A
V
CELL
U
-260mV
V
CELL
U
-200mV
V
CELL
U
-140mV
MITSUMI
Protection of Lithium Ion Batteries (three cells in series) MM1293
Timing Chart
Overcharge state
Sensing dead zone
t
OV
Normal state
Overcharge detection voltage
Cell voltage
COV pin
Pin OV
(pulled up)
Charging off
Overcharge detection cancel voltage
Cell voltage
CDC pin
DCHG pin
Pin PF
Discharge off
Reset dead zone
Overdischarge state
Normal state
t
CDC
1
t
CDC
2
Discharge resume voltage
(pulled up)
Overdischarge detection voltage
Sensing dead zone
CS pin
COL pin
DCHG pin
Normal state
Normal state
Overcurrent state
Reset dead zone
Sensing dead zone
Current passed
from pin CS
Load released
t
COL
t
COL
Overcharge
Overdischarge
Overcurrent
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