BQ24295 Datasheet, PDF (2/45 Pages) Texas Instruments – I2C Controlled 3A Single Cell USB Charger

bq24295
SLUSBC1 – SEPTEMBER 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
The bq24295 is a highly-integrated switch-mode battery charge management and system power path
management devices for 1 cell Li-Ion and Li-polymer battery in a wide range of power bank, tablet and other
portable device applications. Its low impedance power path optimizes switch-mode operation efficiency, reduces
battery charging time and extends battery life during discharging phase. The I²C serial interface with charging
and system settings makes the device a truly flexible solution.
The device supports a 3.9V-6.2V USB input sources, including standard USB host port and USB charging port
with 6.4V over-voltage protection. The bq24295 is compliant with USB 2.0 and USB 3.0 power specifications with
input current and voltage regulation. To set the default input current limit, the bq24295 detects the input source
through D+/D- detection following the USB battery charging spec 1.2. In addition, the bq24295 detects non-
standard 2A/1A adapters. The bq24295 supports battery boost operation by supplying adjustable voltage 4.55-
5.5V (default 5.1V) on PMID pin with minimum current of 1.5A.
The power path management regulates the system slightly above battery voltage but does not drop below 3.5V
minimum system voltage (programmable). With this feature, the system maintains operation even when the
battery is completely depleted or removed. When the input current limit or voltage limit is reached, the power
path management automatically reduces the charge current to zero. As the system load continues to increase,
the power path discharges the battery until the system power requirement is met. This supplement mode
operation prevents overloading the input source.
The devices initiate and complete a charging cycle without software control. It automatically detects the battery
voltage and charges the battery in three phases: pre-conditioning, constant current and constant voltage. At the
end of the charging cycle, the charger automatically terminates when the charge current is below a preset limit in
the constant voltage phase. When the full battery falls below the recharge threshold, the charger will
automatically start another charging cycle.
The devices provide various safety features for battery charging and system operation, including negative
thermistor monitoring, charging safety timer and over-voltage/over-current protections. The thermal regulation
reduces charge current when the junction temperature exceeds 120°C (programmable).
The STAT output reports the charging status and any fault conditions. The INT immediately notifies the host
when a fault occurs.
The bq24295 is available in a 24-pin, 4x4 mm² thin QFN package.
bq24295 Configuration Table
I²C Address
bq24295
6BH
Boost Mode Output
Yes
Adjustable 4.5V-5.5V@1.5A (max)
USB Detection
D+/D-
Default Battery Voltage
4.208V
Default Charge Current
1.024A
Default Adapter Current Limit
3A
Default Pre-charge Current / Max Pre-charge Current
256mA / 2.048A
Default Termination Current
256mA
Charging Temperature Profile
Cold/Hot
Status Output
STAT,
STAT During Fault
Blinking @ 1Hz
Default Safety Timer
12hr
Default VINDPM
4.76V
Default Pre-charge Timer
4hr
2
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