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

Constant Voltage Charging
When the battery voltage reaches V_CH during con-
stant current mode, the AAT3680 transitions to con-
stant voltage mode. The regulation voltage is fac-
tory programmed: 4.1V and 4.2V are available to
support different anode materials in lithium-ion/poly-
mer cells. In constant voltage operation, the
AAT3680 monitors the cell voltage and terminates
the charging cycle when the voltage across R_SENSE
decreases to approximately 10mV.
AAT3680
Lithium-Ion/Polymer
Linear Battery Charge Controller
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
ShSMuhMtouddtooeDdweonwn
Yes
TeTmeFpmaFeuparaleuttrlutarteure
No
Temperature Test
TS > V_TS1
TS < V_TS2
Yes
Preconditioning Test ^Yes
V_MIN > V_BAT
No
Current Phase Test
Yes
V_CH > V_BAT
< V_RCH
No
Voltage
Phase Test
V_TERM
R_SENSE
< I_BAT
Yes
No
ChCaLhragaLtecraghCtecOohCmfOfopmflfeptleete
Low Current
CoLnodwitiConuirnrgent
CCohnadrigtieoning
(TrickleChCahragrege)
Current
ChMCCaMhoruagdorrierdngeeginntg
CVhCoValhtoraagltgriangeggineg
MModoede
Figure 1: AAT3680 Operational Flow Chart.
6
3680.2006.03.1.6