lv51133t ON Semiconductor, lv51133t Datasheet - Page 7

• Manufacturer Part Number: lv51133t
• Description: 2-cell Lithium-ion Secondary Battery Protection Ic
• Manufacturer: ON Semiconductor

Excessive charger detection/release
0V cell charging operation
Shorten the test time
Operation in case of detection overlap
(Note) Short-circuit detection can be made independently.
During over-charge
detection
During over-discharge
detection
During over-current
detection
If the voltage between V - pin and V SS pin becomes equal to or less than the excessive charger detection voltage by
connecting a charger, no charging can be made by turning the Cout pin “L” after delay time and turning off the
external Nch MOS FET. If that voltage returns to equal to or more than the excessive charger detection voltage
during detection delay time, the excessive charger detection will be stopped. If the voltage between V - pin and V SS
pin becomes equal to or more than the excessive charger detection voltage after excessive charger detection, the Cout
returns to “H” after delay time. The detection/return delay time is set internally.
If Dout pin is “L”, charging will be made through the parasitic diode of external Nch FET on Dout pin. In that case,
the voltage between V - pin and V SS pin is nearly -Vf which is less than the excessive-charger detection voltage,
therefore no excessive charger detection will be made during over-discharge, over-current and short-circuit detection.
Furthermore, if excessive voltage charger is connected to the over-discharged battery, no excessive charger detection
is made while the Dout pin is “L”. But the battery is continued charging through the parasitic diode. If the battery
voltage rises to the over-discharge detection voltage and the voltage between V - pin and V SS pin remains equal to or
less than the excessive charger detection voltage, the delay operation will be started after Dout pin turns to “H.”
If voltage between V DD and V becomes equal to or more than the 0V cell charging lowest operation voltage when
the cell voltage is 0V, the Cout pin turns to “H” and charging is enabled.
By turning T pin to the V DD , the delay times set by the internal counter can be cut. If T pin is “open”, “L” the delay
times are normal. Delay time not set by the counter just like as short circuit detection delay cannot be controlled by
this pin.
In some circuit-board layout, an excessive current at the load short might cause this IC be in miss operation like as in
standby mode due to V SS line impedance. Therefore we recommend that the T pin is connected to the V SS pin.
Excessive charger detection cannot be made during over-discharge, over-current and short-circuit detection.
And its delay time starts after the Dout pin returns to “H”.
Overlap state
Over-discharge
detection is made
Over-current
detection is made
Over-charge detection
is made
Over-current
detection is made
Over-charge detection
is made
Over-discharge
detection is made
Over-charge detection is preferred. If over-
discharge state continues even after over-
charge detection, over-discharge detection is
resumed.
(*1) Both detections can be made in parallel.
Over-charge detection continues even when the
over-current state is made first. If the over-
charge state is made first, over-current detection
is interrupted.
Over-discharge detection is interrupted and
over-charge detection is preferred. When over-
discharge state continues even after over-
charge state is made, over-discharge detection
is resumed.
(*3) Both detections can be made in parallel.
Over-discharge detection continues even when
the over-current state is made first. But over-
current detection is interrupted when the over-
discharge state is made first.
(*1)
(*3)
Operation in case of
LV51133T
detection overlap
When over-charge state is made first, V - is
released. When over-discharge is detected after
over-charge state is made, the IC does not go
into the stand-by mode. Note that V - is
connected to V DD via 200kΩ.
(*2) When over-current state is made first, V - is
connected to V SS via 30kΩ. When over-charge
state is made first, V - is released.
The IC does not go into the stand-by mode
when over-discharge state is made after over-
charge detection. Note that V - is connected to
V DD via 200kΩ.
(*4) If over-current state is made first, V - will be
connected to V SS via 30kΩ. If over-discharge
detection is made next, V - will be disconnected
from V SS and connected to V DD via 200kΩ to
get into stand-by mode. If over-discharge state
is made first, V - will be connected to V DD via
200kΩ to get into standby state.
(*2)
(*4)
State after detection
No.A1985-7/9