UB261

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

5 of 10

www.unisonic.com.tw

QW-R502-A27.a



OPERATION

1. Normal Condition

turns both the charging and discharging control FETs on. This condition is called the normal condition, and in this

condition charging and discharging can be carried out freely.

Note: When a battery is connected to the IC for the first time, discharging may not be enabled. In this case, short

2. Overcurrent Condition

overcurrent detection voltage because the discharge current is higher than the specified value and the status lasts

for the overcurrent detection delay time, the discharge control FET is turned off and discharging is stopped. This

the status when the impedance between the EB+ pin and EB- pin (Refer to the typical application circuit) increases

Note: The impedance that enables automatic restoration varies depending on the battery voltage and the set value

of overcurrent 1 detection voltage.

3. Overcharge Condition

turns the charging control FET off to stop charging. This condition is called the overcharge condition. The overcharge

condition is released by the following two cases:

charging control FET on and turns to the normal condition.

(2) When a load is connected and discharging starts, the UTC UB261 series turns the charging control FET on

and returns to the normal condition. Just after the load is connected and discharging starts, the discharging current

UB261

series releases the overcharge condition.

detection of overcurrent 1, overcurrent 2 and load shortcircuiting do not function until the battery voltage falls below

battery voltage drops immediately after a heavy load that causes overcurrent is connected, and the detection of

overcurrent 1, overcurrent 2 and load short-circuiting function.

Note 2: When a charger is connected after the overcharge detection, the overcharge condition is not released