BQ2054 Datasheet, PDF (4/16 Pages) Texas Instruments – Lithium Ion Fast-Charge IC

bq2054
Chip On
VCC 4.5V
Temperature Out
of Range or
Thermistor Absent
Temperature
Checks On
Present
VLCO < VBAT < VHCO
Temperature
in Range
Qualification Test
VBAT < VMIN
Current
Regulation
@ ICOND
PASS: VBAT > VMIN
Battery
Status?
Fail: t = tQT or
VBAT < VLCO
VBAT > VHCO
Absent
VBAT < VLCO or
VBAT > VHCO
Fault
LED3 =1
MOD = 0
VBAT VLCO
or
VBAT VHCO
VBAT < VREG
Phase 1
I = IMAX
Fast
Charge
VBAT > VREG
t > t > tMTO or
VBAT < VLCO or
VBAT > VHCO
Charge
Pending
LED3 flash
MOD = 0
ISNS > IMIN
Phase 2
V = VREG
ISNS < IMIN
or
t > tMTO
VBAT VLCO
or
VBAT VHCO
Charge
Complete
VBAT < VLCO or
VBAT > VHCO
Temperature Out
of Range or
Thermistor Absent
Temperature In
Range, Return
to Original State
FG205401.eps
Figure 2. bq2054 State Diagram
4