Datasheet

ApplyInput
Power
TurnonPGFET – PGpinLOW
SetInputCurrentLimitto 100mA
andStartCharge
PerformISET & OUT shorttests
RememberISET2 State
HasISET2 changedstatesince
DetectionRoutinewasrun?
Yes
Setchargecurrent
basedonISET2 truth
table.
Returnto
Charge
No
Yes
IsChipEnabled &Alive?
V
TS
> V
EN
& V
IN
>V
UVLO
No
Yes
Ispowergood?
V
BAT
+V
DT
< V
IN
< V
OVP
& V
UVLO
< V
IN
No
Yes
Setchargecurrent
basedDetection
Routine..
StartRunningUSB
DetectionRoutine
bq24050
bq24052
bq24055
www.ti.com SLUS940B –SEPTEMBER 2009–REVISED JUNE 2012
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 © 2009–2012, Texas Instruments Incorporated 19