BQ24157 Datasheet, PDF (2/39 Pages) Texas Instruments – Fully Integrated Switch-Mode Charger With USB Compliance and USB-OTG Support

bq24157
SLUSB80 – SEPTEMBER 2012
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 bq24157 is a compact, flexible, high-efficiency, USB-friendly switch-mode charge management device for
single-cell Li-ion and Li-polymer batteries used in a wide range of portable applications. The charge parameters
can be programmed through an I²C interface. The IC integrates a synchronous PWM controller, power
MOSFETs, input current sensing, high-accuracy current and voltage regulation, and charge termination, into a
small WCSP package.
The IC charges the battery in three phases: conditioning, constant current and constant voltage. The input
current is automatically limited to the value set by the host. Charge is terminated based on battery voltage and
user-selectable minimum current level. A safety timer with reset control provides a safety backup for I²C
interface. During normal operation, The IC automatically restarts the charge cycle if the battery voltage falls
below an internal threshold and automatically enters sleep mode or high impedance mode when the input supply
is removed. The charge status can be reported to the host using the I²C interface. During the charging process,
the IC monitors its junction temperature (T_J) and reduces the charge current once T_J increases to about 125°C.
To support USB OTG device, bq24157 can provide VBUS (5.05V) by boosting the battery voltage. The IC is
available in 20-pin WCSP package.
DEVICE SPINS AND COMPARISONS
PART NUMBER
VOVP (V)
D4 Pin Definition
I_CHARGE(MAX) at POR in default mode with R_(SNS) = 68 mΩ and OTG=High on bq24157(mA)
I_CHARGE(MAX) in HOST mode with R_(SNS) = 68 mΩ and Safety Limit Register increased from default (A)
Output regulation voltage at POR (V)
Boost Function
Input Current Limit in Default Mode
Battery Detection at Power Up
I2C Address
PN1 (bit4 of 03H)
PN0 (bit3 of 03H)
Safety Timer and WD Timer
100 ms Power Up Delay
bq24157
6.5
OTG
325
1.25
3.54
Yes
100mA (OTG=LOW);
500mA (OTG=High)
No
6AH
1
0
Disabled
No
2
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