
SWCS045-012
5
1
2
3
4
VBAT_SHORT
VBATMIN_LO
VBATMIN_HI
VBAT_MAX
Battery pre-
conditioning
30 mA
VPRCH_MAX
System
active and
battery
full-charge
Battery
precharge
Input: 92/470 mA limitation
Output: Default 3.54 V/ 500 mA
SWCS045B
– SEPTEMBER 2010 – REVISED JUNE 2011
Full-Charge Phase (Software Controlled)
Full-charge can start only when the battery voltage is above VBATMIN_HI, because this phase is under the
control of the host processor, and it stops when the battery voltage is below VBATMIN_LO. During this phase,
the following resources are available to control the charge process.
Charge current set point register VICHRG[3:0] (constant current mode)
Charge voltage set point register VOREG[5:0] (constant voltage mode)
End of charge current set point register VITERM[2:0] (minimum current when in constant voltage mode)
Input limit current set point register CIN_LIMIT[3:0] (maximum current drawn from charging source)
Input voltage set point register BUCK_VTH[2:0] (VBUS voltage collapsing level)
Charge watchdog set point (programmable up to 127 s, 32 s by default)
If the charging source collapses during the full-charge phase, the full-charge current is automatically reduced to a
value keeping the input voltage higher than the preset value, to ensure proper operation of the charge circuitry.
If the charging current termination is enabled, the charging is stopped if the current decreases below the preset
limit during constant voltage charging. This indicates the end of the charge period.
Figure 12. Battery Thresholds
Charger Controller Operation
If VAC or VBUS is detected when the battery voltage is above VPRCH_MAX, charging is enabled by the charger
controller, but gated by the USB charger and VAC charger because the voltage is above the default charging
Copyright
2010–2011, Texas Instruments Incorporated
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