LP3918 Datasheet, PDF (23/39 Pages) National Semiconductor (TI) – Battery Charge Management and Regulator Unit

LP3918
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Programming Information
BIT
4
5
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Table 12. Register Address 8h'12: CHGCNTL3
NAME
VTERM[0]
VTERM[1]
FUNCTION
Set the charging termination voltage.
See Table 5
Table 13. Register Address 8h'12: CHGCNTL3
BIT
NAME
FUNCTION
0
VRSTRT[0]
Set the charging restart voltage.
1
VRSTRT[1]
See Table 7
Charger Operation
The operation of the charger with EOC enabled is shown in this simplified flow diagram.
From any mode:
V_{CHG_IN} < 4.5V
or V_{CHG_IN} > 6.0V
or disabled via serial interface.
Charger OFF
Zero Current
4.5V < V_{CHG_IN} < 6.0V
Yes
Pre-Charge mode
50mA Constant current
No
V_BATT > 3.0V
Yes
Full-Rate Charge mode
Constant Current (I_CHG)
No
V_BATT = V_TERM
Yes
Full-Rate Charge mode
Constant Voltage (V_TERM)
I_CHG < EOC
No
Yes
Maintenance mode
Zero current
V_BATT < V_RSTRT
No
Yes
Figure 10. Simplified Charger Functional Flow Diagram (EOC is enabled)
The charger operation may be depicted by the following graphical representation of the voltage and current
profiles.
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