MB3836 Datasheet, PDF (14/28 Pages) Fujitsu Component Limited. – Li-Ion Battery Protection IC

MB3836
s OPERATION TIMING CHART
1. Over-charge Detection Block and Cell Voltage Input Block
(1) When cell 3 does not exceed VTH and cells 1 and 2 are lowered in voltage by cell voltage input current
and self-discharging
If any cell voltage reaches or exceeds the over-charge detection voltage (4.325 V Typ), the COUT terminal (pin
2) goes “H” level to turn off the Pch MOS FET for external charge control, after a delay time (23 ms Typ) managed
by the capacitor (COVT) connected between the COVT terminal (pin 14) and GND, thereby stopping charging the
battery. At this time, the cell voltage input block switch is turned on to supply the cell voltage input current to that
cell so that high-voltage cells are lowered in voltage.
When all the cell voltages in the over-charge detected state become the over-charge release voltage (4.125 V
Typ) or less, the COVT terminal (pin 14) and COUT terminal (pin 2) go “L” level to turn on the Pch MOS FET for
external charge control.
When any cell voltage in the over-charge detected state becomes the over-charge release voltage (4.125 V Typ)
or less, the cell voltage input block switch is turned off.
Cell voltage
Cell 1
Cell voltage input
current
Cell 2
COVT terminal
VTH (4.325 V)
VH (0.2 V)
(4.125 V)
(45 µA)
(0 µA)
(45 µA)
(0 µA)
(6.26 V)
Cell 1
Cell 2
COUT terminal
tD (23 ms)
Figure 1
14