fs326 Fortune Semiconductor Corporation, fs326 Datasheet - Page 11

• Manufacturer Part Number: fs326
• Description: One Cell Lithium-ion/polymer Battery Protection Ic
• Manufacturer: Fortune Semiconductor Corporation

Rev. 1.9
12.6
12.7
12.8
12.9
12.10 DS Pin
Charger Detection
Abnormal Charge Current Condition
Over Current / Short Circuit Condition
Release of Over Current / Short Circuit Condition
2)
While connecting to a charger after entering into power-down mode, then if VCSI<VCH, M1 will
be turned on when VDD>VODL. The system will back to normal condition as described in 1) of
previous section since the charger has been detected. This action is called charger detection.
When a charger is connected to the battery system in normal condition, then if VDD<VOCU and
VCSI<VCH occurs through a delay time longer than TOC (delay time of overcharge detection),
M2 will be turned off to stop this charging status. It is called the abnormal charge current
condition.
Abnormal charge current condition is released when the voltage of CSI pin becomes higher than
charger detection voltage (VCH), or the charger is removed.
When the current is too large during discharging under normal condition as a result of the voltage
detected by CSI is greater than VOI1 (or VOI2) through a delay time TOI1 (or TOI2), it satisfies
the over current (or short circuit) condition. Then M1 will be turned off and CSI will be pulled down
to VSS through an internal resistance. It is called the over current (or short circuit) condition.
While the protection IC remains in Over current/Short circuit condition, then if the load is removed
or the impedance between VBAT+ and VBAT- is larger than 500k Ω as well as VCSI<VOI1, M1
will be turned on and then back to normal condition.
By forcing DS to VDD, the delay time of the overcharge and overdischarge can be reduced to
within 50ms; therefore, testing time of protector circuit board can be reduced.1.6M Ω pull down
resistor is connected between DS pin and VSS internally. DS pin should be left open or
connected to VSS in the actual application.
If VCH<VCSI<VOI2, the condition VDD>VODR must be satisfied for M1 to be turned on, and
then the system will back to the normal condition.
If the over current / short circuit is detected and it keeps longer than the overdischarge
detection delay time with the same circumstance, the condition will be changed to the
power-down mode when the battery voltage falls below the overdischarge detection
voltage.
If the battery voltage falls below the overdischarge detection voltage (VODL) due to the
over current / short circuit, the discharging control FET (M1) will be turned off when this
condition occurs. After overdischarge detection delay time (TOD) expired, if the battery
voltage is still equal to or lower than the overdischarge detection voltage, the condition will
then be changed to power-down mode.
FS326
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