BQ24735_17 Datasheet, PDF (33/46 Pages) Texas Instruments – 1- to 4-Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode With N-Channel Power MOSFET Selector

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10.2.3 Application Curves
CH1: PHASE, 20 V/div,
CH2: battery voltage, 5 V/div,
CH3: LODRV, 10 V/div,
CH4: inductor current, 2 A/div, 400 µs/div
Figure 19. Battery Insertion
bq24735
SLUSAK9B – SEPTEMBER 2011 – REVISED APRIL 2015
98
97
96
95
94
93
3-cell 12.6 V
2-cell 8.4 V
4-cell 16.8 V
92
91
90
89
88
0 0.5 1 1.5 2 2.5 3 3.5 4
Charge Current
V_IN = 20 V
F_S = 750 kHz
4.5
L = 4.7 µH
Figure 20. Efficiency vs Output Current
10.3 System Examples
Adapter +
Adapter -
Ri _*
2W
Ci _*
2.2µF
D3
PDS1040
Q1 (ACFET)
FDS6680A
C17
2200 pF
C16
0.1µF
RAC 10 mW
C1
0.1µF
C3
0.1µF
R10
4.02 kW
R1
430 kW
R2
66.5 kW
+3.3V
R3
10 kW
HOST SMBus
Dig I/O
C2
0.1µF
R11
4.02 kW
ACN
ACP
CMSRC
VCC
BATDRV
REGN
ACDRV
ACDET
BTST
R8
100 kW
ILIM
R7
549 kW
HIDRV
U1
bq247 35 ^PHASE
R4
10 kW
R5
10 kW
SDA
LODRV
GND
SCL
ACOK
SRP
ADC
IOUT PowerPad
SRN
C4
100 pF
R9
10 Ω
C5
1µF
R6
4.02 kW
C6
1µF
D1
BAT54
C7
0.047µF
Total
* ^Csys
220µF
SYSTEM
C15
0.01µF
Q5 (BATFET)
FDS6680A
C8
10uF
Q3
Sis412DN
C9
10uF
RSR
10mW
L1
4.7µH
Q4
Sis412DN
C10 C11
10µF 10µF
Pack +
Pack -
R14 _*
10 Ω
R15 _*
7.5 Ω
C13
0.1µF
C14
0.1µF
F_s = 750 kHz, I_ADPT = 2.816 A, I_CHRG = 1.984 A, I_LIM = 2.54 A, V_CHRG = 12.592 V, 65-W adapter and 3S2P battery
pack
Use 0 Ω for better current-sensing accuracy, use 10-Ω or 7.5-Ω resistor for reversed battery connection protection.
See Negative Output Voltage Protection.
The total Csys is the lump sum of system capacitance. It is not required by charger IC. Use Ri and Ci for adapter hot
plug-in voltage spike damping. See Input Filter Design.
Figure 21. Typical System Schematic With One NMOS Selector and Schottky Diode
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