S8239B datasheet(11/25 Pages) SII

11 / 25 page

OVERCURRENT MONITORING IC FOR MULTI-SERIAL-CELL PACK

Rev.1.1_00

S-8239B Series

Seiko Instruments Inc.



Operation

1. Normal status

The S-8239B Series monitors the voltage between the VINI pin and the VSS pin to control discharging. When the

VINI pin voltage is equal to or lower than the overcurrent 1 detection voltage (VDIOV1), the DO pin becomes "High-Z".

This status is called the normal status.

Caution When a battery is connected for the first time, the S-8239B Series may not be in the normal status.

In this case, short the VM pin and VSS pin or connect the charger. The S-8239B Series then

becomes the normal status.

2. Overcurrent status (Overcurrent 1, overcurrent 2, overcurrent 3)

When a battery is in the normal status, if the VINI pin voltage is equal to or higher than the overcurrent detection

voltage because the discharge current is equal to or higher than the specified value and the status continues for the

overcurrent detection delay time or longer, the DO pin becomes VSS potential. This status is called the overcurrent

status. The overcurrent status is retained when the voltage between the VDD pin and the VM pin is equal to or lower

than the overcurrent release voltage (VRIOV).

In the overcurrent status, the VM pin and the VDD pin are shorted by the internal resistance between the VM pin and

the VDD pin (RVMD) in the S-8239B Series.

After that, the overcurrent status is released if the voltage between the VDD pin and the VM pin becomes equal to or

higher than VRIOV by connecting a charger.

3. UVLO status

The S-8239B Series includes a UVLO (under voltage lock out) function to prevent the IC malfunction due to the

decrease of the battery voltage when detecting the overcurrent. When the battery voltage in the normal status is

equal to or lower than the UVLO detection voltage (VUVLO) and the status continues for the UVLO detection delay time

(tUVLO) or longer, the DO pin becomes VSS potential. This status is called the UVLO status.

In the UVLO status, the VM pin and the VDD pin are shorted by RVMD between the VM pin and the VDD pin in the

S-8239B Series.

After that, the UVLO status is released if the battery voltage becomes equal to or higher than VUVLO.

4. Power-down status

In the UVLO status, the current consumption is decreased to the current consumption during power-down (IPDN) if the

voltage between the VDD pin and the VM pin becomes equal to or lower than 0.7 V typ. in the S-8239B Series. This

status is called the power-down status.

Moreover, if the voltage between the VDD pin and the VM pin becomes equal to or lower than 0.7 V typ. and the

status continues for tUVLO or longer in the normal status, the DO pin becomes VSS potential and the S-8239B Series

becomes power-down status.

After that, the power-down status is released if the voltage between the VDD pin and the VM pin is equal to or higher

than 0.7 V typ. by connecting a charger.

S8239B Datasheet(PDF) 11 Page - Seiko Instruments Inc