AAT3680 Datasheet, PDF (6/18 Pages) Advanced Analogic Technologies – Lithium-Ion Linear Battery Charge Controller

AAT3680
Lithium-Ion Linear Battery Charge Controller
Constant Voltage Charging
When the battery's voltage reaches V_CH during
constant-current mode, the AAT3680 transitions to
constant-voltage mode. The regulation voltage is
factory programmed: 4.1V and 4.2V (or 8.2V and
8.4V for two-cell applications) are available to sup-
port different anode materials in Lithium Ion cells.
In constant-voltage operation, the AAT3680 moni-
tors the cell voltage and terminates the charging
cycle when the voltage across R_SENSE decreases to
approximately 10mV.
Charge Cycle Termination, Recharge
Sequence
After the charge cycle is complete, the AAT3680
latches off the pass device and automatically enters
power-saving sleep mode. Either of two possible
conditions will bring the IC out of sleep mode: the
battery voltage at the BAT pin drops below V_RCH
(recharge threshold voltage) or the AAT3680 is reset
by cycling the input supply through the power-on
sequence. Falling below V_RCH signals the IC that it
is time to initiate a new charge cycle.
PoPwoewr _{eOrnORneRseest et}
UVLO
No
V_P > V_UVLO
SShMuhMtuoDtodDdeoewownn
Yes
TTemeFmpFaepuarelutarlttautruere
Temperature Test
No
TS > V_TS1
TS < V_TS2
Yes
Yes
Preconditioning Test
V_MIN > V_BAT
No
Yes
Current Phase Test
V_CH > V_BAT
< V_RCH
No
Voltage
Phase Test
V_TERM
R_SENSE
< I_BAT
Yes
No
ChCaLhragaLtecraghCtecOohCmfOfopmflfeptleete
Low Current
CoLnodwitiConuirnregnt
CCohnadrigtieoning
(TrickleChCahragrege)
CCCMhCuMahorurarodrgerrdeigneneitngntg
CVCMhVoMahlootraaodlgtrgadeignegeigneg
Figure 1: AAT3680 Operational Flow Chart
6
3680.2003.4.0.91