BATTERY PROTECTION IC FOR SINGLE-CELL PACK

S-8261 Series

Seiko Instruments Inc.

1

The S-8261 series are lithium-ion / lithium polymer

rechargeable battery protection ICs incorporating high-

accuracy voltage detection circuit and delay circuit.

The S-8261 series are suitable for protection of single-cell

lithium ion/lithium polymer battery packs from overcharge,

overdischarge and overcurrent.

Features

(1) Internal high accuracy voltage detection circuit

• Overcharge detection voltage

3.9 V to 4.4 V (applicable in 5 mV step)

Accuracy:

±25 mV (+25 °C) and ±30 mV (−5 °C to +55 °C)

• Overcharge hysteresis voltage

0.0 V to 0.4 V

*1

Accuracy:

±25 mV

The overcharge hysteresis voltage can be selected from the range 0.0 V to 0.4 V in 50 mV step.

• Overdischarge detection voltage

2.0 V to 3.0 V (applicable in 10 mV step) Accuracy:

±50 mV

• Overdischarge hysteresis voltage

0.0 V to 0.7 V

*2

Accuracy:

±50 mV

The overdischarge hysteresis voltage can be selected from the range 0.0 V to 0.7 V in 100 mV step.

• Overcurrent 1 detection voltage

0.05 V to 0.3 V (applicable in 10 mV step) Accuracy:

±15 mV

• Overcurrent 2 detection voltage

0.5 V (fixed) Accuracy:

±100 mV

(2) High voltage device is used for charger connection pins

(VM and CO pins: absolute maximum rating

= 28 V)

by an internal circuit. No external capacitor is necessary.

Accuracy:

±20%

(4) Three-step overcurrent detection circuit is included.

(overcurrent 1, overcurrent 2 and load short-circuiting)

(5) 0 V battery charge function “available” / “unavailable” are selectable.

(6) Charger detection function and abnormal charge current detection function

• The overdischarge hysteresis is released by detecting negative voltage at the VM pin (−0.7 V typ.).

(Charger detection function)

• When the output voltage of the DO pin is high and the voltage at the VM pin is equal to or lower than

the charger detection voltage (

−0.7 V typ.), the output voltage of the CO pin goes low. (Abnormal

charge current detection function)

(7) Low current consumption

• Operation mode

3.5

µA typ., 7.0 µA max.

• Power-down mode

0.1

µA max.

(8) Wide operating temperature range

−40 °C to +85 °C

(9) Small package SOT-23-6, 6-Pin SNB(B)

*1. Overcharge release voltage

= Overcharge detection voltage − Overcharge hysteresis voltage

(where overcharge release voltage

< 3.8 V is prohibited.)

*2. Overdischarge release voltage

= Overdischarge detection voltage + Overdischarge hysteresis voltage

(where overdischarge release voltage

> 3.4 V is prohibited.)

Applications

• Lithium-ion rechargeable battery packs

• Lithium polymer rechargeable battery packs