
Seiko Instruments Inc
BATTERY PROTECTION IC FOR 1-CELL PACK
The S-8241 Series is a series of lithiumion/lithium polymer rechargeable battery protection ICs incorporating high-accuracy voltage detection circuits and delay circuits.
These ICs are suitable for protection of 1-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 to 4.4 V (5 mV-step)
Accuracy of ±25 mV(+25 °C) and ± 30 mV(−5 to +55 °C)
•Overcharge release voltage: 3.8 to 4.4 V*1 Accuracy of ±50 mV
•Overdischarge detection voltage: 2.0 to 3.0 V (100 mV-step) Accuracy of ±80 mV
•Overdischarge release voltage: 2.0 to 3.4 V*2 Accuracy of ±100 mV
•Overcurrent 1 detection voltage: 0.05 to 0.3 V (5 mV-step) Accuracy of ±20 mV
•Overcurrent 2 detection voltage: 0.5 V (fixed) Accuracy of ±100 mV
(2) A high voltage withstand device isused for charger connection pins
(VM and CO pins: Absolute maximum rating = 26 V)
(3) Delay times (overcharge: tCU; overdischarge: tDL; overcurrent 1: tlOV1 ; overcurrent 2: tlOV2) are generated by an internal circuit. (External capacitors are unnecessary.) Accuracy of ±30%
(4) Internal three-step overcurrent detection circuit (overcurrent 1, overcurrent 2, and load short-circuiting)
(5) Either the 0 V battery charging function or 0 V battery charge inhibiting function can be selected.
(6) Products with and without a power-down function can be selected.
(7) Charger detection function and abnormal charge current detection function
•The overdischarge hysterisis is released by detecting a negative VM pin voltage (typ. −1.3 V) (Charger detection function).
•If the output voltage at DO pin is high and the VM pin voltage becomes equalto or lower than the charger detection voltage (typ. −1.3 V), the output voltage at CO pin goes low (Abnormal charge current detection function).
(8) Low current consumption
•Operation: 3.0 μA typ. 5.0 μA max.
•Power-down mode: 0.1 μA max.
(9) Wide operating temperature range: −40 to +85 °C
(10) Small package SOT-23-5, SNT-6A
(11) Lead-free products
*1.Overcharge release voltage = Overcharge detection voltage - Overcharge hysteresis
The overcharge hysteresis can be selected in the range 0.0, or 0.1 to 0.4 V in 50 mV steps. (However, selection
“Overcharge release voltage<3.8 V” is enabled.)
*2.Overdischarge release voltage = Overdischarge detection voltage + Overdischarge hysteresis
The overdischarge hysteresis can be selected in the range 0.0 to 0.7 V in100 mV steps. (However, selection
“Overdischarge release voltage>3.4 V” is enabled.)
Applications
•Lithium-ion rechargeable battery packs
•Lithium- polymer rechargeable battery packs