AAT3686_08 Datasheet, PDF (17/23 Pages) Advanced Analogic Technologies – USB Port/AC Adapter Lithium-Ion/Polymer Battery Charger

BatteryManager^TM
PRODUCT DATASHEET
AAT3686
USB Port/AC Adapter Lithium-Ion/Polymer Battery Charger
Digital Charge Status Reporting
The AAT3686 has a comprehensive digital data reporting
system by use of the DATA pin feature. This function can
provide detailed information regarding the status of the
charging system. The DATA pin is a bi-directional port
which will read back a series of data pulses when the
system microcontroller asserts a request pulse. This sin-
gle strobe request protocol will invoke one of 22 possible
return pulse counts which the microcontroller can look up
based on the serial report table shown in Table 4.
The DATA pin function is active low and should normally
be pulled high to V_ADP or V_USB. This data line may also be
pulled high to the same level as the high state for the
logic I/O port on the system microcontroller. In order for
the DATA pin control circuit to generate clean, sharp
edges for the data output and to maintain the integrity
of the data timing for the system, the pull-up resistor on
the data line should be low enough in value so that the
DATA signal returns to the high state without delay. If
too small a pull-up resistor is used, the strobe pulse
from the system microcontroller could exceed the maxi-
mum pulse time and the DATA output control could issue
false status reports. A 1.5kΩ resistor is recommended
when pulling the DATA pin high to 5.0V on either V_ADP or
V_USB inputs. If the data line is pulled high to a voltage
level less than 5.0V, the pull-up resistor can be calcu-
lated based on a recommended minimum pull-up cur-
rent of 3mA. Use the following formula:
R_PULL-UP ≤
V_PULL-UP
3mA
Number
1
2
3
4
DATA Report Status
Chip Over-Temperature Shutdown
Battery Temperature Fault
Over-Voltage Turn Off
Not Used
5
ADP Watchdog Time-Out in Battery Condition Mode
6
ADP Battery Condition Mode
7
ADP Watchdog Time-Out in Constant Current Mode
8
ADP Thermal Loop Regulation in Constant Current
Mode
9
ADP Constant Current Mode
10
ADP Watchdog Time-Out in Constant Voltage Mode
11
ADP Constant Voltage Mode
12
ADP End of Charging
Number
13
14
15
16
DATA Report Status
USBH Battery Condition Mode
USBH Charge Reduction in Constant Current Mode
USBH Constant Current Mode
USBH Constant Voltage Mode
17
USBH End of Charging
18
USBL Battery Condition Mode
19
USBL Charge End of Charging Reduction in
Constant Current Mode
20
USBL Constant Current Mode
21
USBL Constant Voltage Mode
22
USBL End of Charging
23
Data Report Error
Table 4: Serial Data Report Table.
1.8V to 5.0V
IN
AAT3686
Status
Control
OUT
DATA Pin
R_{P UL L _ UP}
GPIO
Figure 4: Data Pin Application Circuit.
IN
OUT
µP GPIO
Port
3686.2007.12.1.11
www.analogictech.com
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