S-8233AKFT-TB-G Seiko Instruments, S-8233AKFT-TB-G Datasheet - Page 13

• Manufacturer Part Number: S-8233AKFT-TB-G
• Description: Battery Management Lithium-Ion battery protection (3 cell)
• Manufacturer: Seiko Instruments

Specifications of S-8233AKFT-TB-G

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Rev.6.0
Normal status
Overcurrent status
Overcharge status
Operation
The overcurrent status returns to the normal status when the load is released and the impedance
This IC monitors the voltages of the three serially-connected batteries and the discharge current to control
charging and discharging. If the voltages of all the three batteries are in the range from the overdischarge
detection voltage (V
batteries becomes equal or lower than a specified value (the VMP pin voltage is equal or lower than
overcurrent detection voltage 1), the charging and discharging FETs turn on. In this status, charging and
discharging can be carried out freely. This status is called the normal status. In this status, the VMP and
VCC pins are shorted by the R
This IC is provided with the three overcurrent detection levels (V
overcurrent detection delay time (t
If the discharging current becomes equal to or higher than a specified value (the VMP pin voltage is equal
to or higher than the overcurrent detection voltage) during discharging under normal status and it
continues for the overcurrent detection delay time (t
discharging. This status is called an overcurrent status. The VMP and VCC pins are shorted by the R
resistor at this time. The charging FET turns off.
When the discharging FET is off and a load is connected, the VMP pin voltage equals the V
If one of the battery voltages becomes higher than the overcharge detection voltage (V
under normal status and it continues for the overcharge detection delay time (t
FET turns off to stop charging. This status is called the overcharge status. The 'H' level signal is output
to the conditioning pin corresponding to the battery which exceeds the overcharge detection voltage until
the battery becomes equal to lower than the overcharge release voltage (V
discharged by connecting an Nch FET externally. The discharging current can be limited by inserting
R11, R12 and R13 resistors (see Figure 9). The VMP and VCC pins are shorted by the R
under the overcharge status.
The overcharge status is released in two cases:
Remark Refer to “
between the EB- and EB+ pins (see Figure 9) is 100 MΩ or higher. When the load is released, the VMP
pin, which and the VCC pin are shorted with the R
detects that the VMP pin potential returns to overcurrent detection voltage 1 (V
overcurrent detection voltage 2 (V
detection 1 is inhibited) and returns to the normal status.
<1> The battery voltage which exceeded the overcharge detection voltage (V
<2> If the battery voltage which exceeded the overcharge detection voltage (V
The release mechanism is as follows: the discharge current flows through an internal parasitic diode of
the charging FET immediately after a load is installed and discharging starts, and the VMP pin voltage
decreases by about 0.6 V from the VCC pin voltage momentarily.
(overcurrent detection voltage 1 or higher), releases the overcharge status and returns to the normal
status.
_00
overcharge release voltage (V
the overcharge release voltage (V
starts, the charging FET turns on and the normal status returns.
DD
) to the overcharge detection voltage (V
Battery Protection IC Connection Example”.
VCM
BATTERY PROTECTION IC FOR 3-SERIAL-CELL PACK
IOV1
resistor.
IOV2
CD
,t
) or lower if the COVT pin is fixed at the 'L' level and overcurrent
), the charging FET turns on and the normal status returns.
IOV2
Seiko Instruments Inc.
CD
), but the charger is removed, a load is placed, and discharging
and t
IOV3
) corresponding to each overcurrent detection level.
VCM
IOV
) or longer, the discharging FET turns off to stop
resistor, goes back to the V
CU
), and the current flowing through the
IOV1
,V
IOV2
The IC detects this voltage
CU
and V
CD
CU
) or longer, the charging
). The battery can be
) is equal or higher than
IOV1
S-8233A Series
CC
CU
IOV3
CU
) or lower (or the
) falls below the
potential. The IC
) during charging
) and the three
SS
potential.
VCM
resistor
VCM
13