BQ25120_15 Datasheet, PDF (45/68 Pages) Texas Instruments – bq25120 700-nA Low IQ Highly Integrated Battery Charge Management Solution for Wearables and IoT

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10 Application and Implementation
BQ25120
SLUSBZ9A – AUGUST 2015 – REVISED AUGUST 2015
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI's customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
10.1 Application Information
A typical design is shown in Figure 34. This design uses the BQ25120 with external resistors for ILIM,
IPRETERM, and ISET. These are not needed if these values are set with a host controller through I²C
commands. This design also shows the TS resistors, which is also optional.
When powering up in default mode the battery voltage is the default for the part (4.2 V), the SYS output is the
default (1.8 V). External resistors set the charge current to 40 mA, the termination current to 10% (4 mA), and
the input current limit to 100 mA. If the I²C interface is used the part goes to the internal default settings until
changed by the host.
10.2 Typical Application
`
1 µF
HOST
4.99 kŸ
4 kŸ
Unregulated
PG
PMID
Load
4.7 µF
IN
VINLS
GND
CD
SDA
SYS
SW
2.2 µH
10 µF
MCU /
SYSTEM
SCL
INT
RESET
LS / LDO
<100mA
1 µF
Load
LSCTRL
MR
IPRETERM
ISET
ILIM
499 Ÿ BQ25120
BAT
1 µF
14.3 kŸ
TS
NTC
14 kŸ
IN
Figure 34. Typical Application Circuit
Copyright © 2015, Texas Instruments Incorporated
Product Folder Links: BQ25120
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