X3100V28Z INTERSIL [Intersil Corporation], X3100V28Z Datasheet - Page 14

• Manufacturer Part Number: X3100V28Z
• Description: 3 or 4 Cell Li-ion Battery Protection and Monitor IC
• Manufacturer: INTERSIL [Intersil Corporation]

Over-charge Protection
The X3100 and X3101 monitor the voltage on each
battery cell (V
time exceeding T
switched OFF (OVP/LMON = V
now entered Over-charge protection mode (Figure 3).
The status of the discharge FET (via pin UVP) will
remain unaffected.
While in over-charge protection mode, it is possible to
change the state of the OVPC bit in the control register
such that OVP/LMON = Vss (Charge FET = ON).
Although the OVPC bit in the control register can be
changed, the change will not be seen at pin OVP until
the X3100 or X3101 returns from over-charge protec-
tion mode.
The over-charge detection delay T
capacitor (C
GND. A typical delay time is shown in Table 10. The
Figure 3. Over-charge Protection Mode—Event Diagram
OVP/LMON
Event
V
CELL
OV
CELL
0
) connected between pin OVT and
OV
). If for any cell, V
Normal Operation Mode
, then the Charge FET will be
14
CC
OV
). The device has
, is varied using a
CELL
1
> V
T
OV
OV
for a
X3100, X3101
2
Over-charge
Protection
delay T
C
equation:
Table 19. Typical over-charge detection time
The device further continues to monitor the battery cell
voltages, and is released from over-charge protection
mode when V
X3100 or X3101 is released from over-charge protec-
tion mode, the charge FET is automatically switched
ON (OVP/LMON = V
over-charge protection mode, the status of the dis-
charge FET (pin UVP/OCP) remains unaffected.
The value of V
shown in Table 4 by setting bits VOV1, VOV0. These
bits are set by using the WCFIG instruction to write to
the configuration register.
Mode
Symbol
OV
T
, can be approximated by the following linear
OV
OV
that results from a particular capacitance
T
CELL
OV
OV
3
(s) ≈ 10 x C
< V
can be selected from the values
0.1µF
SS
C
OV
). When the device returns from
OVR
Normal Operation Mode
, for all cells. When the
OV
(µF).
1.0s (Typ)
Delay
V
V
OV
OVR
January 3, 2008
V
V
CC
SS
FN8110.1