S-8204BAB-TCT1Y Datasheet, PDF (17/36 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

Rev.3.9_00
BATTERY PROTECTION IC FOR 3-SERIES OR 4-SERIES CELL PACK
S-8204B Series
6. Delay time setting
In the S-8204B Series, users are able to set delay time for the period; from detecting the voltage of one of the
batteries or detecting changes in the voltage at the VINI pin, to the output to the COP pin and the DOP pin. Each
delay time is determined by a resistor in the S-8204B Series and an external capacitor.
In the overchage detection, when the voltage of one of the batteries gets V_CUn or more, the S-8204B Series starts
charging to the CCT pin's capacitor (C_CCT) via the CCT pin's internal resistor (R_INC). After a certain period, the COP
pin is set in high impedance if the voltage at the CCT pin reaches the CCT pin detection voltage (V_CCT). This period is
overcharge detection delay time (t_CU).
t_CU is calculated using the following equation (V_DS = V1 + V2 + V3 + V4).
t_CU [s] = −ln (1 − V_CCT / V_DS ) × C_CCT [μF] × R_INC [MΩ]
= −ln (1 − 0.7 (typ.)) × C_CCT [μF] × 8.31 [MΩ] (typ.)
= 10.0 [MΩ] (typ.) × C_CCT [μF]
Overdischarge detection delay time (t_DL), discharge overcurrent detection delay time 1 (t_DIOV1), discharge overcurrent
detection delay time 2 (t_DIOV2) are calculated using the following equations as well.
t_DL [ms] = −ln (1 − V_CDT / V_DS) × C_CDT [μF] × R_IND [kΩ]
t_DIOV1 [ms] = −ln (1 − V_CIT / V_DS) × C_CIT [μF] × R_INI1 [kΩ]
t_DIOV2 [ms] = −ln (1 − V_CIT / V_DS) × C_CIT [μF] × R_INI2 [kΩ]
In case C_CCT = C_CDT = C_CIT = 0.1 [μF], each delay time t_CU, t_DL, t_DIOV1, t_DIOV2 is calculated as follows.
t_CU [s] = 10.0 [MΩ] (typ.) × 0.1 [μF] = 1.0 [s] (typ.)
t_DL [ms] = 1000 [kΩ] (typ.) × 0.1 [μF] = 100 [ms] (typ.)
t_DIOV1 [ms] = 200 [kΩ] (typ.) × 0.1 [μF] = 20 [ms] (typ.)
t_DIOV2 [ms] = 20 [kΩ] (typ.) × 0.1 [μF] = 2.0 [ms] (typ.)
Load short-circuit detection delay time (t_SHORT) is fixed internally.
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