x3101 Intersil Corporation, x3101 Datasheet - Page 20

• Manufacturer Part Number: x3101
• Description: 3 Or 4 Cell Li-ion Battery Protection And Monitor Ic
• Manufacturer: Intersil Corporation

Figure 6. Over-Current Protection Mode—Event Diagram
Table 24. Over-Current Protection Mode—Event Diagram Description
Event
(1,2)
(2,3)
[0,1)
[1]
[2]
UVP/OCP
Event
VCS
Normal Operation Mode
V
P+
— Discharge FET is ON (OCP = Vss). Battery cells are permitted to discharge.
— VCS
— The device is in normal operation mode (i.e. not in a protection mode).
— Excessive current flows through the battery terminals P+, dropping the voltage. (See Figure 6.).
— The positive battery terminal voltage (P+) falls, and VCS
— The internal over-current detection delay timer begins counting down.
— The device is still in Normal Operation Mode
— The internal over-current detection delay timer times out, AND VCS
— The internal over-current sense circuitry switches the discharge FET OFF (UVP/OCP = Vcc).
— The device now begins a load monitor state by passing a small test current (I
— The device has now entered over-current protection mode.
— It is possible to change the status of UVPC and OVPC in the control register, although the status of pins
— The X3100/X3101 now continuously monitors the load resistance to detect whether or not an over-
B+
OC
2
OVP/LMON. This senses if an over-current condition (i.e. if the load resistance < R
P+/P-.
UVP/OCP and OVP/LMON will not change until the device has returned from over-current protection mode.
current condition is still present across the battery terminals P+/P-.
0
21
(VCS
1
The internal Over-current detection delay timer continues counting for T
20
T
OC
2
- VCS
1
2
) is less than the over-current threshold voltage (V
P+ = (RLOAD+RSENSE) x ILMON
X3100, X3101
Over-Current Protection Mode
Event Description
21
exceeds V
3
21
T
OCR
OC
is still above V
OC
.
).
LMON
4
OC
Normal Operation Mode
= 7.5µA) out of pin
OCR
seconds.
OC.
) still exists across
Voc
V
V
V
CC
SS
SS
January 3, 2008
FN8110.1