Datasheet

StartPrecharge
/CHG= Low
Batteryshortdetected?
Yes
No
No
t
PRECHARGE
Elapsed?
BeginCharging
EndCharge
Flash/CHG
I
BAT
< I
TERM
Yes
Yes
TD=Low
(’72, ’73 Only)
(’74, ’75= YES)
No
TerminationReached
BATTFET Off
WaitforV
BAT
< V
RCH
Yes
No
V
BAT
> V
LOWV
StartFastcharge
I
CHARGE
setbyISET
No
EndCharge
Flash/CHG
No
t
FASTCHARGE
Elapsed?
ChargeDone
/CHG= Hi-Z
V
BAT
< V
RCH
No
BatteryDetected?
RunBatteryDetection
Yes
Yes
No
bq24072T
bq24075T, bq24079T
www.ti.com SLUS937A –DECEMBER 2009–REVISED APRIL 2010
CHARGE CURRENT TRANSLATOR
When the charger is enabled, internal circuits generate a current proportional to the charge current at the ISET
input. The current out of ISET is 1/400 (±10%) of the charge current. This current, when applied to the external
charge current programming resistor, R
ISET
, generates an analog voltage that can be monitored by an external
host to calculate the current sourced from BAT.
V
ISET
= I
CHARGE
/ 400 × R
ISET
Figure 33. Battery Charging Flow Diagram
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Product Folder Link(s): bq24072T bq24075T bq24079T