BQ2003 Datasheet, PDF (7/15 Pages) Texas Instruments – Fast-Charge IC

New Charge Cycle Start or
Discharge-Before-Charge
Command
Battery Voltage?
VCELL > VMCV
VEDV < VCELL < VMCV
VCELL < VEDF
Charge
Pending
Battery
Temperature?
VTEMP > VLTF or
VTEMP < VHTF
Trickle
CHG =
1 3/8s high
1/8s low
VCELL > VMCV
VHTF < VTEMP < VLTF
No _{Discharge-Before-Charge}
Commanced?
VEDV < VCELL < VMCV
and
VHTF < VTEMP < VLTF
bq2003
Discharge
CHG =
1 3/8s low
1/8s high
VCELL > VMCV
VCELL <
VEDV
Fast
CHG =
Low
VCELL >
VMCV
Hold-off
period
expired?
- V or
T/ t or
VTEMP < VTCO
or
Maximum
Time Out
No
VCELL <
VMCV
Fast
CHG =
High
Top-off
selected?
Yes
No
Battery
Absent
t > 1.5tMCV
Yes
Trickle
Trickle
CHG =
CHG =
High
High
Hold-off
period
expires
VCELL <
VMCV
VCELL >
VMCV
VCELL >
VMCV
Charge
Complete
Top-off
CHG =
1/8s low
1/8s high
VTEMP < VTCO
or Maximum
Time Out
Trickle
CHG =
1/8s low
1/8s high
SD2003.eps
Figure 3. State Diagram
7