S-8242B Seiko Instruments, S-8242B Datasheet - Page 11

• Manufacturer Part Number: S-8242B
• Description: BATTERY PROTECTION IC
• Manufacturer: Seiko Instruments

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Rev.1.4
3. Overdischarge Status
4. Charger Detection
5. Overcurrent Status
When the battery voltage falls below overdischarge detection voltage n (V
and detection continues for the overdischarge detection delay time (t
discharging control FET off to stop discharging. This condition is called the overdischarge status.
discharging control FET is turned off, the VM pin voltage is pulled up by the resistor between the VM and VDD pins in
the IC (R
consumption is reduced to the power-down current consumption (I
status.
The power-down status is released when a charger is connected and the voltage difference between the VM and
VDD pins becomes 1.3 V (typ.) or higher. Moreover, when the battery voltage becomes overdischarge detection
voltage n (V
When a battery in the overdischarge status is connected to a charger and provided that the VM pin voltage is lower
than the charger detection voltage (V
therefore, the S-8242B Series releases the overdischarge status and turns the discharging control FET on when the
battery voltage becomes equal to or higher than overdischarge detection voltage n (V
function works. This action is called charger detection.
When a battery in the overdischarge status is connected to a charger and provided that the VM pin voltage is not
lower than the charger detection voltage (V
battery voltage reaches overdischarge release voltage n (V
When a battery in the normal status is in the status where the voltage of the VM pin is equal to or higher than the
overcurrent detection voltage because the discharge current is higher than the specified value and the status lasts for
the overcurrent detection delay time, the discharge control FET is turned off and discharging is stopped. This status
is called the overcurrent status.
In the overcurrent status, the VM and VSS pins are shorted by the resistor between VM and VSS (R
However, the voltage of the VM pin is at the V
load is disconnected, the VM pin returns to the V
This IC detects the status when the impedance between the EB + pin and EB − pin (Refer to Figure 13 ) increases and
is equal to the impedance that enables automatic restoration and the voltage at the VM pin returns to overcurrent
detection voltage 1 (V
Caution The impedance that enables automatic restoration varies depending on the battery voltage and the
_00
VMD
set value of overcurrent detection voltage 1.
DLn
). When the voltage difference between the VM and VDD pins then is 1.3 V (typ.) or lower, the current
) or higher, the S-8242B Series turns the discharging FET on and returns to the normal status.
IOV1
) or lower and the overcurrent status is restored to the normal status.
CHA
BATTERY PROTECTION IC FOR 2-SERIAL-CELL PACK
), the overdischarge hysteresis is released via the charge detection function;
Seiko Instruments Inc.
CHA
DD
), the S-8242B Series releases the overdischarge status when the
SS
potential due to the load as long as the load is connected. When the
potential.
DUn
) or higher.
PDN
DL
). This condition is called the power-down
DLn
) or longer, the S-8242B Series turns the
) during discharging in the normal status
DLn
) since the charger detection
S-8242B Series
VMS
) in the IC.
When the
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