BQ24050 Datasheet, PDF (19/37 Pages) Texas Instruments – 800mA Single Cell Li-Ion Battery Charger With Automatic Adaptor/USB Detection

bq24050
bq24052
bq24055
www.ti.com.................................................................................................................................... SLUS940A – SEPTEMBER 2009 – REVISED SEPTEMBER 2009
Apply Input
Power
Is Chip Enabled &Alive? No
V_TS > V_EN
& V_IN>V_UVLO
Start Running USB
Detection Routine
Yes
Is power good?
V_BAT+V_DT < V_IN < V_OVP
No
& V_UVLO < V_IN
Yes
Turn on PG FET – PG pin LOW
Set Input Current Limit to 100mA
and Start Charge
Perform ISET & OUT short tests
Remember ISET2 State
Yes
Has ISET2 changed state since
No
Detection Routine was run?
Yes
Set charge current
based on ISET2 truth
table.
Set charge current
based Detection
Routine..
Return to
Charge
Figure 25. Power-up Flow Diagram
Overvoltage-Protection (OVP) – Continuously Monitored
If the input source applies an overvoltage, the pass FET, if previously on, turns off after a deglitch, t_BLK(OVP). The
timer ends and the CHG and PG pin goes to a high impedance state. Once the overvoltage returns to a normal
voltage, the PG pin goes low, timer continues, charge continues and the CHG pin goes low after a 25ms
deglitch.. PG pin is optional on some packages.
Copyright © 2009, Texas Instruments Incorporated
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