x3102v28 Intersil Corporation, x3102v28 Datasheet - Page 24

• Manufacturer Part Number: x3102v28
• Description: 3 Cell Li-ion Battery Protection And Monitor Ic
• Manufacturer: Intersil Corporation

EVENT
(1,2)
(2,3)
(3,4)
[0,1)
[1]
[2]
[3]
[4]
UVP/OCP
• 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 14.).
• The positive battery terminal voltage (P+) falls, and VCS
• The internal overcurrent detection delay timer begins counting down.
• The device is still in Normal Operation Mode
The internal Overcurrent detection delay timer continues counting for T
• The internal overcurrent detection delay timer times out, AND VCS
• The internal overcurrent 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 overcurrent protection mode.
• It is possible to change the status of UVPC and OVPC in the control register, although the status of pins UVP/OCP and OVP/LMON
• The X3102 now continuously monitors the load resistance to detect whether or not an overcurrent condition is still present across
• The device detects the load resistance has risen above R
• Voltages P+ and VCS
• The test current from pin OVP/LMON is stopped (I
• The device has now returned from the load monitor state
• The internal overcurrent release time timer begins counting down.
• Device is still in overcurrent protection mode.
The internal overcurrent release timer continues counting for T
• The internal overcurrent release timer times out, and VCS
• The device returns from overcurrent protection mode, and is now in normal operation mode.
• The discharge FET is automatically switched ON (UVP/OCP = Vss) - unless the status of UVPC has been changed in the control
• The status of the charge FET remains unaffected.
• Discharge of the battery cells is once again possible.
Event
VCS
an overcurrent condition (i.e. if the load resistance < R
will not change until the device has returned from overcurrent protection mode.
the battery terminals P+/P-.
register during the overcurrent protection mode.
V
OC
B+
P+
Normal Operation Mode
2
21
0
(VCS
2
1
TABLE 24. OVERCURRENT PROTECTION MODE-EVENT DIAGRAM DESCRIPTION
–VCS
24
1
T
FIGURE 14. OVERCURRENT PROTECTION MODE - EVENT DIAGRAM
) is less than the overcurrent threshold voltage (V
OC
21
return to their normal levels.
2
P+ = (RLOAD+RSENSE) x ILMON
Overcurrent Protection Mode
LMON
EVENT DESCRIPTION
X3102
OCR
21
= 0µA)
OCR
21
) still exists across P+/P-.
exceeds V
OCR
is still below V
.
seconds.
21
OC
is still above V
OC
OC
seconds.
.
).
OC.
LMON
3
= 7.5µA) out of pin OVP/LMON. This senses if
OC.
T
OCR
4
Normal Operation Mode
Voc
V
V
V
SS
CC
SS
December 22, 2004
FN8246.0