Datasheet

RAC
0.010
RSR
0.010
Q1 (ACFET)
SI4435
PP
CSSN
CSSP
ACIN
VREF
CE
SDA
SCL
SMBus
DISCRETE
LOGIC
VICM
HOST
(EC)
DCINP
BOOT
VDDP
PGND
CSOP
CSON
PACK +
PACK -
CHRG_IN
ADAPTER
+
ADAPTER -
AGND
bq24765
464k
1%
33.2k
1%
R1
R2
1uF
C4
0.1uF
C2
0.1uF
C3
100pFC5
0.47uF
C6
0.1uF
C7
L1
3.3uH
D1 BAT54
1uF
C8
C9
0.1uF
C10
0.1uF
C12
10uF
C18
10uF
VFB
ICOUT
C11
10uF
Q2 (ACFET)
SI4435
Controlled
byHOST
10uF
C17
C13
0.1u
R4
10k
R5
10k
EAI
FBO
EAO
R9
20k
R10
200k
R8
7.5k
C15
2000pF
C16
130pF
VDDSMB
ACOK
10k
R3
DISCRETE
LOGIC
DigI/O
R7
10k
C14
51pF
DCINP
DCINP
DCINA
PHASE
PHASE
PHASE
PGND
PGND
Q3 (BATFET)
SI4435
P
Controlled
byHOST
N
N
QTOP
QBOT
2.2uF
C1
Rc1
2
R7
5.6
PHASE
PHASE
PGND
20
RC6
ICREF
RC1
100k
RC2
20k
R6
10k
bq24765
SLUS999 –NOVEMBER 2009 www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
DESCRIPTION (CONTINUED)
The bq24765 features Dynamic Power Management (DPM) and input power limiting. These features reduce
battery charge current when the input power limit is reached to avoid overloading the AC adaptor when supplying
the load and the battery charger simultaneously. A high-accuracy current sense amplifier enables accurate
measurement of input current from the AC adapter, allowing monitoring the overall system power. If the adapter
current is above the programmed low-power threshold, a signal is sent to host so that the system optimizes its
power performance according to what is available from the adapter. An integrated comparator allows monitoring
the input current through the current sense amplifier, and indicating when the input current exceeds a
programmable threshold limit. The bq24765 features a thermal regulation loop to reduce battery charge current
when the T
j
limit is reached. This feature protects internal power FETs from overheating when charging with high
current.
TYPICAL APPLICATIONS
V
IN
= 20 V, V
BAT
= 4-cell Li-Ion, I
CHARGE
= 4.5 A, Idpm = 5A
Figure 1. Typical System Schematic, Using Internal Input Current Comparator
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Product Folder Link(s) :bq24765