BQ24257 Datasheet, PDF (2/45 Pages) Texas Instruments – 2A Single Input I2C, Standalone Switch-Mode Li-Ion Battery Charger with Integrated Current Sense Resistor

bq24257
bq24258
SLUSBG0B – FEBRUARY 2013 – REVISED JULY 2013
www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION CONTINUED
The bq24257 has two modes of operation: 1) I2C mode, and 2) Standalone mode. In I2C mode, the host can
adjust the charge parameters and monitor the status of the charger operation. In Standalone mode, the external
resistor sets the input current limit, charge current limit, and the input DPM level. This mode also serves as the
default settings when a DCP adapter is present. The bq24257 enters host mode while the I2C registers are
accessed and the watchdog timer has not expired (if enabled).
The bq24258 has only one mode of operation which is the Standalone. In this mode, the external resistor sets
the input current limit, charge current limit, and the input DPM level. This mode also serves as the default
settings when a DCP adapter is present. The EN1, EN2, and EN3 pin is available in the bq24258 spin to support
USB 3.0 compliance.
The battery is charged in four phases: trickle charge, pre-charge, constant current and constant voltage. In all
charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if
the internal temperature threshold is exceeded. Additionally, a voltage-based, JEITA compatible battery pack
thermistor monitoring input (TS) is included that monitors battery temperature for safe charging.
CPMID
1µF
VBUS
D-
D+
GND
CIN
2.2P F
PMID
IN
VDPM
3 MHz
PWM
D-
D+
SW
BOOT
PGND
CSIN
LO
1.0PH
CBOOT
33 nF
1PF
VGPIO
1 PF
LDO
Rsns
BAT
22 P F
System Load
SCL
SDA
Host _GPIO1
GPIO2
GPIO3
SCL
SDA
STAT
/CE
/PG
LDO
TS
TEMP
PACK+
+
PACK-
ILIM ISET
2
Submit Documentation Feedback
Product Folder Links: bq24257 bq24258
Copyright © 2013, Texas Instruments Incorporated