S-8204AAB-TCT1Y Datasheet, PDF (16/34 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC FOR 3-SERIES OR 4-SERIES CELL PACK
S-8204A Series
Rev.3.5_00
7. Delay time setting
In the S-8204A 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, DOP pin.
Each delay time is determined by a resistor in the S-8204A Series and an external capacitor.
In the overchage detection, when the voltage of one of the batteries gets V_CUn or more, the S-8204 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), charge overcurrent detection delay time (t_CIOV) 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]
t_CIOV [ms] = −ln (1 − V_CIT / V_DS) × C_CIT [μF] × R_INI1 [kΩ]
In case C_CCT = C_CDT = C_CIT = 0.1 [μF], each delay time t_CU, t_DL, t_DIOV1, t_DIOV2, t_CIOV 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.)
t_CIOV [ms] = 200 [kΩ] (typ.) × 0.1 [μF] = 20 [ms] (typ.)
Load short-circuit detection delay time (t_SHORT) is fixed internally.
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