Datasheet

V
IN(MIN)
30ms
deglitch
Adaptor detection
control
VBUS
ISHORT
Delay 10ms
HiZ
Enable Adaptor Detection
-----------------
Enable Input current sink
Start 30ms timer
V
BUS
> V
IN(MIN)
?
30ms timer
expired?
Bad Adaptor Detected
-----------------
Disable Input current sink
CHBADI = 1
Delay T
INT
Good Adaptor Detected
-----------------
Disable Input current sink
Enable V
IN
based DPM
CHARGE
YES
NO YES
NO
TPS65200
SLVSA48 –APRIL 2010 www.ti.com
Figure 49. Bad Adaptor Detection Circuit Figure 50. Bad Adaptor Detection Flow-Chart
Input Current Limiting at Start Up
The LOW_CHG bit is automatically set when VBUS is asserted to limit the charge current to 150 mA. This
ensures that a battery cannot be charged with high currents without host control.
Charge Profile
In charge mode, TPS65200 has five control loops to regulate input voltage, input current, charge current, charge
voltage and device junction temperature. During the charging process, all five loops are enabled and the one that
is dominant will take over the control. The TPS65200 supports a precision Li-ion or Li-polymer charging system
for single-cell applications. Figure 52 indicates a typical charge profile without input current regulation loop and it
is similar to the traditional CC/CV charge curve, while Figure 53 shows a typical charge profile when input current
limiting loop is dominant during the constant current mode, and in this case the charge current is higher than the
input current so the charge process is faster than the linear chargers. For TPS65200, the input current limits, the
charge current, termination current, and charge voltage are all programmable using I
2
C interface.
Precharge to Fast Charge Threshold (VSHORT)
A deeply discharged battery (V
BAT
< V
SHORT
) is charged with a constant current of I
SHORT
(typically 30 mA) until
the voltage recovers to > V
SHORT
at which point fast charging begins. The pre-charge to fast-charge threshold
has a default value of 2.1 V and can be adjusted by connecting a resistor from the VSHRT pin to ground. An
internal current source forces a 10-µA current into the resistor and the resulting voltage is compared to half the
battery voltage to determine if the battery is deeply discharged or shorted. Therefore the voltage on the VSHRT
pin equals half of V
SHORT
threshold. For example a 100-kΩ resistor connected from VSHRT to GND results in a
2-V precharge to fast charge transition point. If the VSHRT pin is left floating or is shorted to the VDD pin, an
internal reference voltage of 1.05 V is used resulting in a 2.1-V pre-charge to fast-charge threshold.
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