BQ24085_17 Datasheet, PDF (27/42 Pages) Texas Instruments – 750-mA Single-Chip Li-Ion and Li-Pol Charge Management IC With Thermal Regulation

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bq24085, bq24086, bq24087, bq24088
SLUS784E – DECEMBER 2007 – REVISED DECEMBER 2015
Typical Applications (continued)
PIN
COMPONENTS
IN
In most applications, the minimum input capacitance needed is a 0.1-μF ceramic decoupling
capacitor near the input pin connected to ground (preferably to a ground plane through vias).
The recommended amount of input capacitance is 1 μF or at least as much as on the output
pin. This added capacitance helps with hot plug transients, input inductance and initial
charge transients.
OUT
There is no minimum value for capacitance for this output, but TI recommends to connect a
1-μF ceramic capacitor between OUT and ground. This capacitance helps with termination,
and cycling frequency between charge done and refresh charge when no battery is present.
It also helps cancel out any battery lead inductance for long leaded battery packs. TI also
recommends to put as much ceramic capacitance on the input as the output so as not to
cause a drop out of the input when charging is initiated.
ISET/BAT
For stability reasons, it may be necessary to put a 0.1-μF capacitor between the ISET and
BAT pin..
STAT1/2 and PG Optional (LED STATUS – See below, Processor Monitored; or no status)
STAT1
Connect the cathode of a red LED to the open-collector STAT1 output, and connect the
anode of the red LED to the input supply through a 1.5-kΩ resistor that limits the current.
STAT2
Connect the cathode of a green LED to the open-collector STAT2 output, and connect the
anode of the green LED to the input supply through a 1.5-kΩ resistor that limits the current.
PG
Connect the cathode of an LED to the open-collector PG output, and connect the anode of
the LED to the input supply through a 1.5-kΩ resistor to limit the current.
9.2.1.3 Application Curves
8
800
7
700
6
VIN
600
5
500
4
400
3
IBAT
300
2
200
VPG
1
100
0
0
0 5 10 15 20 25 30 35 40 45 50
t - Time - mS
Figure 19. Input OVP Recovery Transients
VIN
PG
t - Time - ms
Figure 20. PG Deglitch Time
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