Texas Instruments BQ25123, Manual

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7 Pin Configuration and Functions
1 2 3 4 5
A
B
C
D
E
Not to scale
GND IN PMID SW PGND
BAT BAT PMID VINLS SYS
ISET ILIM TS VINLS LS/LDO
IPRETERM INT RESET PG GND
MR CD LSCTRL SDA SCL
Figure 7-1. YFP Package 25-Pin (DSBGA) Top View
Table 7-1. Pin Functions
PIN
I/O DESCRIPTION
NAME NO.
BAT B1, B2 I/O
Battery Connection. Connect to the positive terminal of the battery. Bypass BAT to GND with
at least 1 µF of ceramic capacitance.
CD E2 I
Chip Disable. Drive CD low to place the part in High-Z mode with battery only present, or
enable charging when V
IN
is valid. Drive CD high for Active Battery mode when battery only
is present, and disable charge when V
IN
is present. CD is pulled low internally with 900 kΩ.
GND A1, D5 - Ground connection. Connect to the ground plane of the circuit.
ILIM C2 I
Adjustable Input Current Limit Programming. Connect a resistor from ILIM to GND to
program the input current limit. The input current includes the system load and the battery
charge current. Connect ILIM to GND to set the input current limit to the internal default
threshold. ILIM can also be updated through I
2
C.
IN A2 I
DC Input Power Supply. IN is connected to the external DC supply. Bypass IN to GND with
at least 1 µF of capacitance using a ceramic capacitor.
INT D2 O
Status Output. INT is an open-drain output that signals charging status and fault interrupts.
INT pulls low during charging. INT is high impedance when charging is complete, disabled,
or the charger is in high impedance mode. When a fault occurs, a 128µs pulse is sent out as
an interrupt for the host. INT charge indicator function is enabled/disabled using the EN_INT
bit in the control register. Connect INT to a logic rail using an LED for visual indication of
charge status or through a 100kΩ resistor to communicate with the host processor.
IPRETERM D1 I
Termination current programming input. Connect a 0-Ω to 10-kΩ resistor from IPRETERM to
GND to program the termination current between 5% and 20% of the charge current. The
pre-charge current is the same as the termination current setting. Connect IPRETERM to
GND to set the termination current to the internal default threshold. IPRETERM can also be
updated through I
2
C.
ISET C1 I
Fast-Charge Current Programming Input. Connect a resistor from ISET to GND to program
the fast-charge current level. Connect a resistor from ISET to GND to set the charge current
to the internal default. ISET can also be updated through I
2
C. While charging, the voltage
at ISET reflects the actual charging current and can be used to monitor charge current if an
ISET resistor is present and the device is not in host mode.
BQ25123
SLUSCZ6A – JANUARY 2018 – REVISED MAY 2021
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