BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK

S-8242B Series

Seiko Instruments Inc.

10

Operation

Remark

Refer to “

Battery Protection IC Connection Example

”.

1. Normal Status

This IC monitors the voltage of the battery connected between the VDD and VSS pins and the voltage difference

between the VM and VSS pins to control charging and discharging. When the battery voltage is in the range from

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

and discharging can be carried out freely.

Caution When the battery is connected for the first time, discharging may not be enabled. In this case,

short the VM pin and VSS pin or connect the charger to restore the normal status.

2. Overcharge Status

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

The overcharge status is released in the following two cases ((1) and (2)).

control FET on and returns to the normal status.

(2) When a load is connected and discharging starts, the S-8242B Series turns the charging control FET on and

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

the S-8242B Series releases the overcharge condition.

load is connected, overcurrent 1 and overcurrent 2 do not function until the battery voltage falls

of tens of m

Ω, the battery voltage drops immediately after a heavy load that causes overcurrent

is connected, and overcurrent 1 and overcurrent 2 function.

2. When a charger is connected after overcharge detection, the overcharge status is not released

the charger.