BQ2954 Datasheet, PDF (4/18 Pages) Texas Instruments – Lithium Ion Charge Management IC with Integrated Switching Controller

bq2954
VCC "Up"
Volt Fault: When VBAT > VHCO
Time Fault: When T = MTO/4 in State S02 or T = MTO in S03a
Hold Time: A VHCO Fault or State charge held off for 0.740s to 1.12s
Mod = 0
Power-On
Reset
No Action
VBAT< VRCHG
QUALIFICATION
Latch DSEL/CSEL Inputs
Battery Removal
S01
VBAT < 0.8V Reset Faults
Latch DSEL/CSEL Inputs
Temp Not Valid
0.8V > VBAT > VHCO
Hold Time
Hold-off Faults
CHG = 0
Battst = 1
Temp Valid
VHCO < VBAT >0.8V
Reset MTO
CONDITIONING
S02
VBAT < VMIN: ISNS = IMAX/10
Hold Time
CHG = 1
Temp Not Valid
VBAT >VMIN
Reset MTO
CURRENT
REGULATION
S03a
Temp Not Valid
VBAT = VREG
Time Fault
T = MTO/25
ISNS = IMAX: VBAT<VREG
T< MTO
Hold Time
CHG = 1
Volt or Time Fault
VBAT > VHCO or T = MTO
Fault
CHG = 0
Volt or
Time Fault
Full Charge
Indication
VOLTAGE
REGULATION
ISNS = IMIN
S03b
Temp Not Valid
T = MTO
ISNS = ITRM
DONE _S04
Temp Not Hot andVBAT<VRCHG
1s Hold Time after VBAT < VRCHG
VT_{<BAMTT=OVREG: IMAX >} ISNS > ITRMN
CHG = 1
Volt Fault
VBAT > VHCO
Temp Hot
VBAT > VRCHG
Hold-off MOD
VRCHG < VBAT < VHCO
CHG = 1
Volt Fault
VBAT > VHCO
VBAT Voltages:
VRCHG = 1.92V 0.5V
VMIN = 1.50V 0.5V
VREG = 2.05V
VHCO = 2.30V
FGbg295401.eps
Figure 2. bq2954 Charge Algorithm
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