LC05111CMT

www.onsemi.com

10

(1) Normal mode



LC05111CMT controls charging and discharging by detecting cell voltage (VCC) and controls S2-S1

current. In case that cell voltage is between over-discharge detection voltage (Vuv) and over-charge

detection voltage (Vov), and S2-S1 current is between charge over-current detection current (Ioch) and

discharge over-current detection current (Ioc), internal power MOS FETs as CHG_SW, DCHG_SW are all

turned ON.

This is the normal mode, and it is possible to be charged and discharged.

(2) Over-charging mode



Internal power MOS FET as CHG_SW will be turned off if cell voltage will get equal to or higher than

over-charge detection voltage (Vov) over the delay time of over-charging (Tov).

This is the over-charging detection mode.



The recovery from over-charging will be made after the following three conditions are all satisfied.

a. Charger is removed from IC.

b. Cell voltage will get lower than over-charge release voltage (Vovr) over the delay time of over-charging

release (Tovr) due to discharging through load.

Consequently, internal power MOS FET as CHG_SW will be turned on and normal mode will be resumed.



In over-charging mode, discharging over-current detection is made only when CS pin will get higher than

discharging over-current detection current 2(Ioc2), because discharge current flows through parasitic diode

of CHG_SW FET.

If CS pin voltage will get higher than discharging over-current detection current 2 (Ioc2) over the delay time

of discharging over-current 2 (Toc2), discharging will be shut off, because internal power FETs as

DCHG_SW is turned off.(short-circuit detection mode)

After detecting short-circuit, CS pin will be pulled down to Vss by internal resistor Rcsd.

The recovery from short circuit detection in over-charging mode will be made after the following two

conditions are satisfied.

a. Load is removed from IC.

b. CS pin voltage will get equal to or lower than discharging over-current detection current 2 (Ioc2) due to CS

pin pulled down through Rcsd.

Consequently, internal power MOS FET as DCHG_SW will be turned on, and over-charging detection mode

will be resumed.

(3) Over-discharging mode



If cell voltage will get lower than over-discharge detection voltage (Vuv) over the delay time of

over-discharging (Tuv), discharging will be shut off, because internal power FETs as DCHG_SW is turned

off.

This is the over-discharging mode.

After detecting over-discharging, CS pin will be pulled up to Vcc by internal resistor Rcsu and the bias of

internal circuits will be shut off. (Stand-by mode)

In stand-by mode, operating current is suppressed under 0.95uA (max).



The recovery from stand-by mode will be made by internal circuits biased after the following two conditions

are satisfied.

a. Charger is connected.



If CS pin voltage will get lower than charger detecting voltage (Vchg) by connecting charger under the

condition that cell voltage is lower than over-discharge detection voltage, internal power MOS FET as

DCHG_SW is turned on and power dissipation in power MOS FETs is suppressed.

*In case that charging current is low enough, ripple current will be appeared at S2 terminal when CS pin

voltage is near by the threshold of charger detecting voltage (Vchg).

It is caused that the two modes, charger detected and charger not detected (charging through parasitic

diodes of DCHG_SW, is alternately appeared.

Continue into next page