BQ25070 Datasheet, PDF (1/21 Pages) Texas Instruments – 1A, Single-Input, Single-Cell LiFePO4 Linear Battery Charger with 50mA LDO

bq25070
www.ti.com
SLUSA66 – JULY 2011
1A, Single-Input, Single-Cell LiFePO₄ Linear Battery Charger with 50mA LDO
Check for Samples: bq25070
FEATURES
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• Single Cell LiFePO₄ Charging Algorithm
• 30V Input Rating, With 10.5V Over-Voltage
Protection (OVP)
• 50mA Integrated Low Dropout Linear
Regulator (LDO)
• Programmable Charge Current Through Single
Input Interface (CTRL)
• 7% Charge Current Regulation Accuracy
• Thermal Regulation and Protection
• Soft-Start Feature to Reduce Inrush Current
• Battery NTC Monitoring
• Charging Status Indication
• Available in Small 2mm × 3mm 10 Pin SON
Package
APPLICATIONS
• Smart Phones
• Mobile Phones
• Portable Media Players
• Low Power Handheld Devices
DESCRIPTION
The bq25070 is a highly integrated LiFePO₄ linear battery charger targeted at space-limited portable applications.
It operates from either a USB port or AC Adapter and charges a single-cell LiFePO₄ battery with up to 1A of
charge current. The 30V input voltage range with input over-voltage protections supports low-cost unregulated
adapters.
The bq25070 has a single power output that charges the battery and powers the system. The charge current is
programmable up to 1A using the CTRL input. Additionally, a 4.9V ±10% 50mA LDO is integrated into the IC for
supplying low power external circuitry.
The LiFePO₄ charging algorithm removes the constant voltage mode control usually present in Li-Ion battery
charge cycles. Instead, the battery is fastcharged to the overcharge voltage and then allowed to relax to a lower
float charge voltage threshold. The removal of the constant voltage control reduces charge time significantly.
During the charge cycle, an internal control loop monitors the IC junction temperature and reduces the charge
current if an internal temperature threshold is exceeded. The charger power stage and charge current sense
functions are fully integrated. The charger function has high accuracy current and voltage regulation loops, and
charge status display.
APPLICATION SCHEMATIC
USB or TA
VBUS
GND
D+
D-
C1
0.1 mF
R1
1 kW
bq25070
CHG
IN
OUT
VGPIO
R2
100 kW
C2
1 mF
CTRL
BAT
TS
IMON
GND
LDO
PWRPD
TEMP
PACK +
PACK -
C3
R5
0.1 mF ^{1.5 kW} R3
1.5 kW
R4
1.5 kW
STATUS
VDD
ABB
VCHG DET
USB DET
VUSBIN
ACDET
GPIO
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2011, Texas Instruments Incorporated