fs325a Fortune Semiconductor Corporation, fs325a Datasheet - Page 7

• Manufacturer Part Number: fs325a
• Description: Lithium-ion/polymer Battery Protection Ic
• Manufacturer: Fortune Semiconductor Corporation

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Fortune Semiconductor Co.
http://www.fsc.com.tw
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Note: When a battery is connected to FS325 for the first time, it may not enter the normal condition
Note 1: After entering into the overcharge condition, if the charger remains connected and
Normal Condition
The FS325 monitors the voltage of the battery connected between VDD and VSS. The charge and
discharge scheme will be sensed by the voltage difference between CSI and VSS. When
VODL<VDD<VOCU and VCH<VCSI<VOI1, FS325 will turn on the charging (M2) and discharging
(M1) control MOSFETs. The charging and discharging processes can be operated normally. This is
called the normal condition.
Overcharge Condition
When the battery voltage becomes higher than the overcharge detection voltage (VOCU) during
normal charging condition through a delay time longer than TOC (the overcharge detection delay
time), FS325 will turn M2 off to stop charging. This condition is called the overcharge condition.
Release of Overcharge Condition
There are two ways to return to normal condition from overcharge condition.
1)
2)
Note 2: After entering the overcharge condition, if the charger remains connected and VCSI<VCH,
Overdischarge Condition
When the battery voltage falls below the overdischarge detection voltage (VODL) during discharging
condition through a delay time longer than TOD (the overdischarge detection delay time), FS325 will
turn M1 off to stop discharging. This is called the overdischarge condition. In the meanwhile, CSI is
pulled up to VDD by way of internal resistance. If VCSI>VOI2, FS325 will enter into power-down
mode. While in this mode, the current consumption is lower than 0.1μA.
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When the battery is self discharging, and if VDD<VOCR and VOI1>VCSI>VCH occurs, M2 will be
turned on and back to normal condition.
Remove the charger and connect FS325 to a load, the discharging current will flow through the
parasitic diode of M2. At this moment, VCSI increases a voltage (V
the VSS level momentarily. While VCSI>VOI1 and VDD<VOCU occurs, M2 will be turned on and
back to normal condition.
(dischargeable may not be enabled). In this case, short the CSI and VSS pins or connect a
charger to restore to the normal condition.
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VOI1>VCSI>VCH, then M2 will be turned on when the voltage of the battery is lower than
VOCR (because the self-discharge of the battery). The system can enter the charging status
again as
then M2 will be kept off even though the voltage of the battery is lower than VOCR (because
the self-discharge of the battery), and the system will not be allowed to back to the charging
status.
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TEL : [phone]
FAX: [phone]
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7/16
Lithium-ion/Polymer Battery Protection IC
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) of the parasitic diode from
TD-0403005 Rev. 1.3
FS325