MM1433 Просмотр технического описания (PDF) - Mitsumi

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MM1433

Lithium-Ion Battery Charge Control (1 to 2 cells)

Mitsumi 

MITSUMI

Lithium-Ion Battery Charge Control (1 to 2 cells) MM1433

4) Pin 12 (TDET) is open.

· At the start of charging, charge waiting results in the following cases (initially prohibited, but charging

starts when the voltage returns to the normal range):

1) AC adapter supply voltage is less than VADPL or higher than VADPH.

2) Pin 12 (TDET) voltage is outside the range from battery temperature detection voltage L1 (VTL1) to

battery temperature detection voltage H (VTH). Even during charging or when fully charged, neither

LED will light up and the timer will be reset if pin 12 (TDET) voltage is outside the temperature range.

AC adapter abnormality detection, RESET and TDET will operate similarly.

· Except in the above cases, charging starts.

1.2 1mA Charging Operation

· When charging starts, if the battery's voltage is below the low voltage detection voltage (VLV), the

battery is charged using the 1mA charging current.

· If the battery is overdischarged, a time limit is provided by a 1mA charging timer in order to protect the

battery if the battery voltage does not rise because of some problem. If battery voltage does not reach

VLV within the time set by the 1mA charging timer, charging is prohibited.

· See "OSC CR Settings" on the data sheet for the 1mA charge timer setting.

1.3 Preparatory Charging Operation

· When battery voltage is higher than low voltage detection voltage (VLV), the battery is

charged by pre-charge current. The standard preparatory charging current is determined by dividing

current limit 2 (VL2) by the value of the external resistance (0.3-Ω recommended) between pins 14 and 15.

This status is maintained until the battery's voltage rises and the voltage at pin 13 reaches the

preparatory charging detection voltage (VP).

· However, if for some reason the battery does not reach the preparatory charge detection voltage (VP),

the preparatory charge timer limits the time in this state in order to protect the battery. If the battery

does not reach the preparatory charge detection voltage (VP) within the preparatory charge timer's

setting, charging is disabled.

· See "OSC CR Settings" on the data sheet for the preparatory charge timer setting.

1.4 Full Charging Operation

· When the battery voltage rises and the voltage at pin 13 reaches the preparatory charge detection

voltage (VP), charging starts using the full charging current. The standard full charging current is

determined by dividing the current limit 1 (VL1) by the value of the external resistance (0.3-Ω

recommended) between pins 14 and 15.

· As the battery voltage rises, operation switches from constant current charging to constant voltage

charging when the voltage at pin 13 approaches the output voltage at the BAT pin (VBAT).

· After switching to constant voltage charging, the charging current is gradually reduced. When the

charging current drops below the value determined by dividing the full-charge detection value by the

external resistance (0.3-Ω recommended) between pins 14 and 15, charging continues for the value of

the full-charge detection delay timer, then stops, and the open collector NPN transistor at pin 21 (LED

G) turns ON.

· However, a time limit is provided by a full-charge timer in order to protect the battery if, due to some

abnormality, battery voltage does not reach BAT pin output voltage (VBAT), or if charging current does

not drop off after switching to constant voltage charging and full charge detection does not operate.

After the full charge timer setting time has elapsed, charging will be prohibited in the above cases.

· See "OSC CR Settings" on the data sheet for the full-charge detection delay timer setting and full-

charge timer setting

· If, at the start of charging, the battery is already at BAT pin voltage, charging is continued for the value

of the full-charge detection delay timer and then stops, and the open collector NPN transistor at pin 21

(LED G) turns ON.

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