AAT3686
USB Port/AC Adapter
Lithium-Ion/Polymer Battery Charger
When the input supply is disconnected or drops
below UVLO or EN = 0, the charger will automati-
cally enter power-saving sleep mode. Consuming
an ultra-low 0.3µA in sleep mode (1µA for
AAT3686-1), the AAT3686 minimizes battery drain
when it is not charging. This feature is particularly
useful in applications where the input supply level
may fall below the battery charge or under-voltage
lockout level. In such cases where the AAT3686
input voltage drops, the device will enter sleep
mode and automatically resume charging once the
input supply has recovered from its fault condition.
System Operation Flow Chart
ADP
Voltage Test
ADP > VADPP
Yes
ADP
Yes
Yes
UVLO
P > VUVLO
Output
ADPP
Switch
On
Power Select
V
No
No
No
Sleep
Mode
USB
ADP
Loop
Enable
0
1
Power On
Reset
USB Low
Current Loop
USB Detect
USBSEL = ?
Thermal
Loop Enable
USB High
Current Loop
No
Timing
Expire
Device Temp. Monitor
J > 110°C
T
Fault
Conditions Monitor
OV, OT
Yes
Yes
Thermal Loop
Current
Reduction in ADP
Charging Mode
Shutdown
Mode
Yes
No
Battery
Temp. Monitor
TS1 < TS < VTS2
No
Battery
Temp. Fault
V
Charge
Safety
Timer
Timer
Set
Yes
No
Yes
Low Current
Conditioning
Charge
Recharge Test
Preconditioning Test
MIN > VBAT
VRCH > VBAT
V
No
Yes
Yes
Current
Charging
Mode
Current Phase Test
VEOC > VBAT
No
USB Loop
Current
Reduction in USB
Charging Mode
Voltage
Charging
Mode
Voltage Phase Test
I
BAT > ITERM
Yes
No
No
USB Voltage Test
VUSB < 4.5V
USB Voltage
Regulation
Enable
Charge
Completed
12
3686.2006.10.1.9
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
