S-8209BAA-T8T1Y Datasheet, PDF (12/26 Pages) Seiko Instruments Inc – BATTERY PROTECTION IC

BATTERY PROTECTION IC WITH CELL-BALANCE FUNCTION
S-8209B Series
Rev.3.6_00
1. Normal status
In the S-8209B Series, both of CO and DO pin get the V_DD level; the voltage between VDD and VSS (V_DS) is more
than the overdischarge detection voltage (V_DL), and is less than the overcharge detection voltage (V_CU) and
respectively, the CTLC pin input voltage (V_CTLC) > the CTLC pin voltage "L" (V_CTLCL), the CTLD pin input voltage
(V_CTLD) > the CTLD pin voltage "L" (V_CTLDL). This is the normal status.
2. Overcharge status
In the S-8209B Series, the CO pin is in high impedance; when V_DS gets V_CU or more, or V_CTLC gets V_CTLCL or less.
This is the overcharge status.
If V_DS gets the overcharge release voltage (V_CL) or less, and V_CTLC gets the CTLC pin voltage "H" (V_CTLCH) or more,
the S-8209B Series releases the overcharge status to return to the normal status.
3. Overdischarge status
In the S-8209B Series, the DO pin is in high impedance; when V_DS gets V_DL or less, or V_CTLD gets V_CTLDL or less. This
is the overdischarge status.
If V_DS gets the overdischarge release voltage (V_DU) or more, and V_CTLD gets the CTLD pin voltage "H" (V_CTLDH) or
more, the S-8209B Series releases the overdischarge status to return to the normal status.
4. Cell-balance function
In the S-8209B Series, the CB pin gets the level of VDD pin; when V_DS gets the cell-balance detection voltage (V_BU)
or more. This is the charge cell-balance function.
If V_DS gets the cell-balance release voltage (V_BL) or less again, the S-8209B Series sets the CB pin the level of VSS
pin.
In addition, the CB pin gets the level of VDD pin; when V_DS is more than V_DL, and V_CTLD is V_CTLDL or less. This is the
discharge cell-balance function.
If V_CTLD gets V_CTLDH or more, or V_DS is V_DL or less again, the S-8209B Series sets the CB pin the level of VSS pin.
5. Delay circuit
In the S-8209B Series, users are able to set delay time which is from detection of changes in V_DS, V_CTLC, V_CTLD to
output to the CO, DO, CB pin.
For example in the detection of overcharge status, when V_DS exceeds V_CU, or V_CTLC gets V_CTLCH or less, charging to
C_CDT starts via R_CDT. If the voltage between CDT and VSS (V_CDT) reaches the CDT pin detection voltage (V_CDET), the
CO pin is in high impedance. The output pin delay time t_D is calculated by the following formula.
t_D [s] = 10.0 MΩ (typ.) × C_CDT [μF]
The electric charge in C_CDT starts to be discharged when the delay time has finished.
The delay time that users have set for the CO pin, as seen above, is settable for each output pin DO, CB.
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