S-8264AAA-I8T1U Datasheet, PDF (15/36 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC FOR 2-SERIAL

Rev.4.2_02
BATTERY PROTECTION IC FOR 2-SERIAL TO 4-SERIAL-CELL PACK (SECONDARY PROTECTION)
S-8264A/B/C Series
 Operation
Remark Refer to “ Battery Protection IC Connection Example”.
1. Overcharge Detection
When the voltage of one of the batteries exceeds the overcharge detection voltage (V_CU) during charging under normal
conditions and the state is retained for the overcharge detection delay time (t_CU) or longer, CO becomes “H”. This state
is called overcharge. Connecting FET to the CO pin provides charge control and a second protection.
In the S-8264A/C Series, if the voltage of each of the batteries is lower than V_CU + the overcharge hysteresis voltage
(V_HC) and the state is retained for the overcharge release delay time (t_CL) or longer, CO becomes “L”.
In the S-8264B Series, if the voltage of each of the batteries is lower than V_CU + V_HC and the state is retained for t_CL or
longer, the overcharge state is released; however, CO stays at “H”. When the CTL pin is switched from “L” to “H”, CO
becomes “L”.
2. Overcharge Timer Reset Operation
When an overcharge release noise that forces the voltage of one of the batteries temporarily below V_CU is input during
t_CU from when V_CU is exceeded to when charging is stopped, t_CU is continuously counted if the time the overcharge
release noise persists is shorter than the overcharge timer reset delay time (t_TR). Under the same conditions, if the time
the overcharge release noise persists is t_TR or longer, counting of t_CU is reset once. After that, when V_CU has been
exceeded, counting t_CU resumes.
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