BQ24704 Datasheet, PDF (3/31 Pages) Texas Instruments – Low Cost, Host-Controlled Li-Ion and Li-Polymer Battery Charger With Low Iq

bq24704
www.ti.com........................................................................................................................................................................................................ SLUS838 – MAY 2009
ADAPTER +
ADAPTER–
R10
2Ω
C1
2.2 µF
P
P
Q1 (ACFET) Q2 (ACFET)
SI4435
SI4435
Controlled by
HOST
C2
R1
0.1 µF
432 kΩ
1%
R_AC
0.01 Ω
C3
0.1 µF
ACGOOD
R2
66.5 kΩ
1%
VREF
R11
100 kΩ
R12
47 kΩ
VREF
R3
10 kΩ
R14
42 kΩ
R13
100 kΩ
R4
C4
10 kΩ
1 µF
GPIO
HOST
ADC
10 kΩ
R15
REGN
C5
100 pF
D2
BAT54
C6 ^C7
10 µF ^{10 µF}
ACN
ACP
ACDET
AGND
ACGOOD
SRSET
ACSET
VREF
bq24704
PVCC
HIDRV
PH
BTST
REGN
LODRV
PGND
C8
0.1 µF
C9
Q3(BATFET)
SI4435
Controlled by
HOST
Q4
FDS6680A
L1
8.2 µH
P
R_SR
0.01 Ω
D1 BAT54 ^{0.1 µF}
C11
10 µF
C10
1 µF
C13
0.1 µF
Q5
FDS6680A
C14
0.1 µF
DPMDET
CELLS
CHGEN
SRP
SRN
BAT
C15
0.1 µF
VADJ
IADAPT
ISYNSET
PowerPad
R6
20 kΩ
SYSTEM
C12
10 µF
PACK+
PACK–
(1) Pull-up rail could be either VREF or other system rail.
(2) SRSET/ACSET could come from either DAC or resistor dividers.
(3) V_IN = 20 V, V_BAT = 3-cell Li-Ion, I_CHARGE = 3 A, I_{ADAPTER_LIMIT} = 4 A
Figure 2. Typical System Schematic, Voltage and Current Programmed by Resistor
Part Number
bq24704
ORDERING INFORMATION
Package
24-PIN 4 x 4 mm QFN
Ordering Number
(Tape and Reel)
bq24704RGER
bq24704RGET
Quantity
3000
250
PACKAGE THERMAL DATA
PACKAGE
QFN – RGE⁽¹⁾⁽²⁾
θ_JA
45°C/W
T_A=25°C POWER RATING
2.33 W
DERATING FACTOR ABOVE
T_A= 25°C
0.023 W/°C
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
Web site at www.ti.com.
(2) This data is based on using the JEDEC High-K board and the exposed die pad is connected to a Cu pad on the board. This is
connected to the ground plane by a 2x3 via matrix.
Copyright © 2009, Texas Instruments Incorporated
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