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Protection for Lithium-Ion Batteries

MM4128B/MM4129B Series


The MM4128B / MM4129B series is a double protection IC for 2 cell Li batteries. It detects battery voltage for each cell. The configuration of delay time can be achieved. Output at the time of detection can be held for a fixed period of time; therefore, this can maintain a regular disconnection time of a fuse. In addition, high cell voltage can be dropped and then stopped at the level where battery deterioration does not occur by Electrical discharge function of the IC after disconnecting the fuse.

Product Series

For 2-cells secondary protection


(1) Range and accuracy of detection and release voltage
 • Overcharge detection voltage 3.6V~5.0V, 5mV Step Accuracy±15mV
 • Overcharge release voltage 3.1V~5.0V, 50mV Step Accuracy±50mV
• Standby detection voltage Selection from 2.5V or 3.5V Accuracy±300mV

(2) Range of detection delay time
 • Overcharge detection delay time Selection from 1s or 2s or 4s or 8s
 • Overcharge release delay time Selection from Selection from 1ms or 2ms or 4ms or 8ms or 16ms
 • Overcharge detection timer reset delay time 16ms fixed

(3) Range of internal regulator voltage
 • COUT terminal output voltage H 1.8V or 3.3V or 4.7V

(4) Current consumption
 • Current consumption(Vcell=4.0V) Typ. 0.85uA Max. 1.70uA
 • Current consumption at standby(Vcell=2.0V) Typ. 0.15uA Max. 0.30uA


Package Stand by function Overcharge detection voltage
Overcharge release voltage
Overcharge detection delay time
Overcharge release delay time



Associated Data

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