MITSUMI
Protection of Lithium-Ion Batteries MM1412
Protection of Lithium-Ion Batteries
Monolithic IC MM1412
Outline
This IC protects lithium ion batteries in the event of overcharge, overdischarge and overcurrent. It has the
following two functions: an overcurrent detection function that turns the external FET-SW off when a problem
occurs during charging, etc. and excess voltage is impressed on each battery for longer than a certain time,
and an overdischarge detection function that turns the external FET-SW off when battery voltage drops below
a certain voltage during discharge, in order to prevent battery overdischarge. When these functions operate,
the IC is put into low consumption current mode. It also has an overcurrent detection function that turns the
FET-SW off when excess current flows due to a short or the like.
Temperature conditions A: Ta=-25 ~ 75°C, B: Ta=-20 ~ 70°C, C: Ta=0 ~ 50°C,
D: Ta=0 ~ 40°C, E: Ta=-20 ~ 25°C
Series Table
Model
Overcharge Overdischarge Overdischarge Overcurrent
Overcharge
Overcharge
detection voltage detection
detection
reset
detection
detection
hysteresis
temperature
SOP-8C, E VSOP-8A voltage (V)
voltage (V)
voltage (V)
voltage (mV)
voltage (V)
conditions
AW
4.350±0.025
C
220±50
2.3±0.1
3.5±0.2
150±15
Package
CW
EF
EW
FW
GW
HW
JW
KW
LW
MW
NW
PW
4.295±0.025
4.250±0.025
4.250±0.025
4.300±0.025
4.225±0.025
4.250±0.025
4.350±0.025
4.125±0.025
4.125±0.025
4.190±0.025
4.300±0.025
C
C
C
C
C
C
C
C
C
C
C
220±50
150±50
220±50
300±50
220±50
220±50
2.3±0.1
2.3±0.1
2.0±0.1
2.0±0.1
2.3±0.1
4.5±0.2
2.3±0.1
2.3±0.1
2.0±0.1
2.0±0.1
2.0±0.1
3.5±0.2
3.5±0.2
3.1±0.2
3.1±0.2
3.1±0.2
3.5±0.2
3.5±0.2
3.1±0.2
3.1±0.2
3.5±0.2
150±15
150±15
150±15
140±15
150±15
150±15
100±15
150±15
100±15
100±15
75±15
MM1412
Features
1. Consumption current (during overcharge)
V
CELL
= 4.5 R
OC
= 270 kΩ
2. Consumption current (normal)
V
CELL
= 3.5V
3. Consumption current (during overdischarge) V
CELL
= 1.9V
4. Consumption current (during overdischarge) V
CELL
= 1.0V
5. Overcharge detection voltage (Ta = 0°C ~ 50°C)
6. Hysteresis voltage
7. Overdischarge detection voltage
8. Overdischarge release voltage
9. Overcurrent detection threshold
10. Reset after overcurrent detection
11. Operating limit voltage
150µA typ.
15µA typ.
0.5µA typ.
0.1µA max.
435 ± 25mV (detected for each cell)
220mV ± 50mV (detected for each cell)
2.30 ± 0.1V (detected for each cell)
3.50V ± 0.2V (detected for each cell)
150mV ± 15mV
Load open
0.9V max.
Package
VSOP-8A
SOP-8C
SOP-8E
MITSUMI
Protection of Lithium-Ion Batteries MM1412
Applications
1. Cell phone
2. Movie
Pin Assignment
1
2
8
7
6
5
3
4
1
2
3
4
5
6
VSOP-8A
7
8
OC
GD
CS
GND
TD
VL
V
CC
VH
Block Diagram
MITSUMI
Protection of Lithium-Ion Batteries MM1412
Pin Description
Pin No. Pin name
Overcharge detection output pin
1
OC
PNPT
R
open collector output
Overcharge mode: ON
Normal mode, overdischarge mode, overcurrent mode: OFF
Discharge control FET (N-ch) control output pin
2
GD
Normal mod, overcharge mode: H
Overdischarge mode, overcurrent mode: L
Overcurrent detection input pin
3
CS
Monitors discharge current equivalently by the voltage drop between discharge control FET source
and drain. Stops discharge when voltage between CS pin and GND pin goes above overcurrent
detection threshold value, and holds until load is released.
4
5
GND
TD
VL
V
CC
VH
Ground pin, or lower cell load negative pole input pin.
Overcharge detection dead time setting pin
Dead time can be set by adding a capacitor between TD and GND pins.
Battery intermediate potential input pin
Connection pin for lower cell positive electrode side and upper cell negative electrode side.
Power supply input pin
Upper cell positive electrode input pin
Functions
6
7
8
Note: Mode Descriptions
(1) Overcharge mode
Either H cell or L cell battery voltage exceeds overcharge detection voltage. Overcharge detection
operation delay can be set by the dead time setting pin.
(2) Normal mode
Both H and L cell battery voltages exceed overdischarge detection voltage and are less than
overcharge detection voltage.
(3) Overdischarge mode
Either H or L cell battery voltage is less than overdischarge detection voltage.
Overdischarge detection dead time is set internally. Overdischarge mode is released when charging
causes voltage to rise above overdischarge detection voltage. Also, when battery voltage goes above
overdischarge release voltage, it resets without charging, but the value is set high. (This function is
included in case charging can not be detected. Also, this release voltage has a temperature coefficient
of -6mV/°C.)
(4) Overcurrent mode
Voltage between CS and GND exceeds overcurrent detection voltage during discharge.
MITSUMI
Protection of Lithium-Ion Batteries MM1412
Pin Description
Pin No. Pin name
Equivalent circuit diagram
Pin No. Pin name
Equivalent circuit diagram
1
OC
5
TD
2
GD
6
VL
3
CS
8
VH
MITSUMI
Protection of Lithium-Ion Batteries MM1412
Absolute Maximum Ratings
Item
Storage temperature
Operating temperature
Power supply voltage
OC pin impressed voltage
CS pin impressed voltage
Allowable loss
Symbol
T
STG
T
OPR
V
CC
max.
V
OC
max.
V
CS
max.
Pd
Ratings
-40~+125
-20~+70
-0.3~+18
-0.6~V
CC
-0.6~V
CC
300
Unit
°C
°C
V
V
V
mW
Recommended Operating Conditions
Item
Operating temperature
Operating power supply voltage
Symbol
T
OPR
V
OP
Ratings
-20~+70
+0.9~+18
Unit
°C
V
Electrical Characteristics
(Except where noted otherwise, Ta=25°C) Models listed MM1412A
Item
Symbol
Measurement conditions
Min. Typ. Max. Unit
Overcharge detection voltage
V
OC
Ta=0°C~50°C
4.325 4.350 4.375 V
Overcharge detection hysteresis voltage
V
OC
170 220 270 mV
Overdischarge detection voltage
V
OD
2.20 2.30 2.40
V
Consumption current 1
I
VH1
V
H
=V
L
=1.0V V
CS
=1.4V
0.1
µA
V
H
=V
L
=1.9V V
CS
=3.2V
0.5
0.8
µA
Consumption current 2
I
VH2
V
H
=V
L
=3.5V
15.0 20.0 µA
Consumption current 3
I
VH3
V
H
=V
L
=4.5V, R
OC
=270kΩ
150
µA
Consumption current 4
I
VH4
V
H
=V
L
=3.5V
-0.3
0
0.3
µA
VL pin input current
I
VL
Discharge resume by voltage rise
3.30 3.50 3.70
V
Overdischarge release voltage
V
DF
V
H
=V
L
=3.5V, IL=-10µA
V
H
-0.3 V
H
-0.2
V
GD pin H output voltage
V
GDH
V
H
=V
L
=3.5V, IL=10µA
0.2
0.3
V
GD pin L output voltage
V
GDL
OC pin output current
I
OCH
V
H
=V
L
=4.5V
30
150
µA
Overcurrent detection threshold value
V
CS1
135 150 165 mV
Overcurrent short threshold value
V
CS2
When both battery pack pins are shorted 0.35 0.45 0.55
V
Overcurrent release
Load release: Load of 5MEGΩ or more between both battery pack pins
Overcurrent detection delay time 1
t
OC
1
7
12
18
ms
Overcurrent detection delay time 2
t
OC
2
30
100
µs
*
1
Overdischarge detection delay time
t
OD
8
13
20
ms
Overcharge detection dead time
t
OCH
C
TC
=0.18µF
0.5
1.0
1.5
s
V
H
=V
L
=2.5V
-0.24 -0.12 -0.04 V
Start-up voltage
V
ST
Note 1: Overcurrent short mode delay time (overcurrent delay time 2) is IC response speed.
In actual use, the time for discharging the discharge control FET gate capacity is added.
Also, when voltage change is large due to excess current, the IC internal bias current may turn off
temporarily, causing response time to lengthen. Select the time constant for the capacitor
connected to the power supply pin so that power supply fluctuation is more than 100µs/1V.
Note 2: Calculate overcharge dead time according to the following formula:
Overcharge detection dead time: t
ALM
- 5.55
[C
TD
: external capacitor, Unit:µF]
C
TD
[s]
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