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MITSUMI
Protection of Lithium Ion Batteries (one cell) MM1291
Protection of Lithium Ion Batteries (one cell)
Monolithic IC MM1291
Outline
1-Cell Protection ICs
This is a protection IC for one-cell series that protects lithium ion batteries during excess charging,
discharging, or overcurrent. If abnormalities occur during charging and excess voltage is applied, it has a
function that turns off the external FET switch when voltage is applied to each battery beyond a specified time
(overcharging detection). It also has a function that turns off the external FET switch when the voltage for
each battery falls below a set voltage, to prevent excess discharge when discharging the battery (discharging
detection). At that time, the IC is switched to low current consumption mode. Also, when there is a large
current flow due to shorting or other reasons, there is a functions for turning off the external FET switch
(overcurrent detection). These function comprise a protection circuit, with few external parts, for lithium ion
batteries.
Package
Overcharge
Overdischarge
Release Overcurrent detection
detection
Hysteresis
Dead time
detection voltage
Delay
SOP-8 VSOP-8
voltage
Overcurrent Detec time shot-mode
MM1291AF AW 4.35V 200mV
*
2.6V 2.4V
2.9V 100mV No
BF BW 4.25V 200mV
*
2.6V 2.4V
2.9V 100mV No
CF 4.10V 25mV
*
2.6V 2.4V
2.9V 150mV No
DF 4.35V 25mV
*
2.6V 2.4V
2.9V 100mV No
EF 4.35V 27mV
*
2.6V 2.4V
2.9V 100mV No
GF 4.225V 27mV
*
2.6V 2.4V
2.9V 100mV No
HF HW 4.35V 200mV
*
2.6V 2.4V
2.9V 50mV 0.45V
JW 4.25V 270mV 2.3V 2.9V 125mV 0.45V
KF 4.25V 200mV 2.3V 2.9V 50mV 0.9V
MW 4.30V 270mV 2.3V 2.9V 125mV 0.45V
at
Ctd=
0.082µF
min. 0.5S
typ. 1S
max. 1.5S
min. 5mS
typ. 10mS
max. 15mS
min. 5mS
typ. 10mS
max. 15mS
Note : Under open-load conditions, returns to normal mode from overcurrent mode.
(For MM1291A to G, J, M, 5MΩ or higher; for MM1291H, K, 50MΩ or higher)
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MITSUMI
Protection of Lithium Ion Batteries (one cell) MM1291
Features
1. Current consumption (during overcharging) VCC=4.5V VCC pin 40µA typ. VIN pin 3µA typ.
2. Current consumption (normal) V
CC=3.5V VCC pin 7µA typ. VIN pin 2µA typ.
3. Current consumption (during excess discharge) V
CC=1.9V 0.7µA typ.
4. Consumption current (during excess discharge) V
CC=1.0V 0.17µA max.
5. Overcharge detection voltage (Ta=
-
20°C~+70°C) A 4.35V±50mV
B 4.25V±50mV
C 4.10V±50mV
6. Overcharge detection hysteresis A 200mV typ.
B 200mV typ.
C 27mV typ.
7. Overcharge non-induction time C
TD=0.082µF 1S typ.
8. Excess discharge voltage 1 V
CS=0V 2.6V±0.1V
9. Excess discharge voltage 2 V
CS=0.05V 2.4V±0.1V
10.Excess discharge reset voltage 2.9V±0.12V
11.Excess discharge during non-induction 10mS typ.
12.Overcurrent detection voltage A 100mV±10mV
B 100mV±10mV
C 150mV±15mV
13.Reset after overcurrent detection load release
14.Overcurrent detection non-induction time 10mS typ.
Package
SOP-8C, SOP-8D (MM1291 F)
VSOP-8A (MM1291 W)
*
The box represents the rank resulting from the combination of protection functions.
Applications
1. Cellular phones
2. PHS
3. MD
4. others
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MITSUMI
Protection of Lithium Ion Batteries (one cell) MM1291
Pin Assignment
1 GND
2 GD
3 CS
4 OC
5 CE
6 TD
7 V
CC
8 VIN
Pin Description
Pin NO.
NAME I/O Description
1 GND Input
Negative power supply for this IC. Also acts as detection pin for the battery
connected between V
IN-GND.
2 GD Output
Nch-FET gate connection pin for discharge control. Switches gate OFF when
excess discharge is detected, and for current protection. Switches gate ON when
excess discharge is detected in normal state.
3 CS Input
Detection pin for voltage between CS-GND. Detects excess discharge using Nch-
FET (discharge control) ON resistor and discharge current.
4 OC Output
Control pin for Nch-FET for charge control. Switches FET off by activating an
external transistor when excess charging is detected.
5 N.C
6 TD Input
This pin sets non-induction time for overcharge detection. It charges the capacitor
connected between TD-GND with a fixed current during overcharging.
7 V
CC Input Positive power supply pin for the IC.
8 V
IN Input Detection pin for the battery connected between VIN-GND.