AIC1802 AIC [Analog Intergrations Corporation], AIC1802 Datasheet - Page 7

• Manufacturer Part Number: AIC1802
• Description: Two-Cell Lithium-Ion Battery Protection IC
• Manufacturer: AIC [Analog Intergrations Corporation]

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APPLICATION INFORMATIONS
THE OPERATION
Overcharge Protection
When the voltage of either of the battery cells
exceeds V
beyond
charging is inhibited by the turning-off of the
charge control MOSFET M2. The overcharge
delay time (T
extended by adding a capacitor C
charging is immediately released when the
voltage of the overcharged cell becomes lower
than V
discharge.
Overdischarge Protection
When the voltage of either of the battery cells
goes below V
voltage) beyond the overdischarge delay time
period, discharging is inhibited by the turning-off
of the discharge control MOSFET M1. The
overdischarge delay time (T
and can be extended by adding a capacitor C
Inhibition of discharging is immediately released
when the voltage of the overdischarged cell
becomes
release voltage) through charging.
Power-Down after Overdischarge
When overdischarge occurs, the AIC1802 will go
into power-down mode, turning off all the timing
generation and detection circuitry to reduce the
quiescent current to 0.8 A (V
unusual
overdischarged while the other under overcharge
condition, the AIC1802 will turn off all the
OCR
the
case
OCP
(overcharge release voltage) through
higher
OC
overcharge
) defaults to 25mS and can be
ODP
(overcharge protection voltage)
where
than
(overdischarge
one
V
delay
OD
ODR
) defaults to 25mS
CC
battery
TC
=4.8V). In the
(overdischarge
time
. Inhibition of
protection
cell
period,
TD
is
.
detection circuits except the overcharge detection
circuit for the cell under overcharge condition.
Charge Detection after Overdischarge
When overcharge occurs, the discharge control
MOSFET M1 turns off and discharging is inhibited.
However, charging is still permitted through the
parasitic diode of M1. Once the charger is
connected to the battery pack, the AIC1802
immediately turns on all the timing generation and
detection circuitry and goes into normal mode.
Charging is determined to be in progress if the
voltage between CS and GND is below –0.4V
(charge detection threshold voltage V
Overcurrent Protection
In normal mode, the AIC1802 continuously
monitors the discharge current by sensing the
voltage of CS pin. If the voltage of CS pin
exceeds V
beyond overcurrent delay time T
overcurrent
discharging is inhibited by turning-off of the
discharge control MOSFET M1. Discharging must
be inhibited for at least 256mS after overcurrent
takes place to avoid damage to external control
MOSFETs due to rapidly switching transient
between
overcurrent condition returns to the normal mode
when the load is released and the impedance
between the V
higher. For the sake of protection of the external
MOSFETs, the larger the CS pin voltage (which
means the larger discharge current) the shorter
the overcurrent delay time. The relationship
between voltage of CS pin and overcurrent delay
V
OIP
BAT+
protection
BAT+
(overcurrent protection voltage)
and V
and
BAT-
V
circuit
BAT-
terminals is 10M
terminals.
AIC1802
operates
OI
CH
period, the
)
The
and
or
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