BQ24171 Datasheet, PDF (1/35 Pages) Texas Instruments – JEITA Compliant Stand-Alone Switch-Mode Li-Ion and Li-Polymer Battery Charger with Integrated MOSFETs and Power Path Selector

bq24171
www.ti.com
SLUSAF2A – FEBRUARY 2011 – REVISED MAY 2011
JEITA Compliant Stand-Alone Switch-Mode Li-Ion and Li-Polymer
Battery Charger with Integrated MOSFETs and Power Path Selector
Check for Samples: bq24171
FEATURES
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• JEITA Compatible Battery Temperature
Sensing
• 1.6MHz Synchronous Switch-Mode Charger
with 4A Integrated N-MOSFETs
• Up to 94% Efficiency
• 30V Input Rating with Adjustable Over-Voltage
Protection
– 4.5V to 17V Input Operating Voltage
• Battery Charge Voltage
– 1, 2, or 3-Cell with 4.2V/Cell
• High Integration
– Automatic Power Path Selector Between
Adapter and Battery
– Dynamic Power Management
– Integrated 20-V Switching MOSFETs
– Integrated Bootstrap Diode
– Internal Loop Compensation
– Internal Digital Soft Start
• Safety
– Thermal Regulation Loop Throttles Back
Current to Limit T_j = 120°C
– Thermal Shutdown
– Battery Thermistor Sense Hot/Cold Charge
Suspend & Battery Detect
– Input Over-Voltage Protection with
Programmable Threshold
– Cycle-by-Cycle Current Limit
• Accuracy
– ±0.5% Charge Voltage Regulation
– ±4% Charge Current Regulation
– ±4% Input Current Regulation
• Less than 15μA Battery Current with Adapter
Removed
• Less than 1.5mA Input Current with Adapter
Present and Charge Disabled
• Small QFN Package
– 3.5mm × 5.5mm QFN-24 Pin
APPLICATIONS
• Tablet PC
• Netbook and Ultra-Mobile Computers
• Portable Data Capture Terminals
• Portable Printers
• Medical Diagnostics Equipment
• Battery Bay Chargers
• Battery Back-Up Systems
DESCRIPTION
The bq24171 is highly integrated stand-alone Li-ion
and Li-polymer switch-mode battery charger with two
integrated N-channel power MOSFETs. It offers a
constant-frequency synchronous PWM controller with
high accuracy regulation of input current, charge
current, and voltage. It closely monitors the battery
pack temperature and allows charge only in a JEITA
profile compatible window with lower charge rate at
low temperature and lower charge voltage at high
temperature. It also provides battery detection,
pre-conditioning, charge termination, and charge
status monitoring. The thermal regulation loop
reduces charge current to maintain the junction
temperature of 120°C during operation.
The bq24171 charges the battery in three phases:
preconditioning, constant current, and constant
voltage. It is adjustable for up to three series Li+
cells.
Charge is terminated when the current reaches 10%
of the fast charge rate. A programmable charge timer
offers a safety back up. The bq24171 automatically
restarts the charge cycle if the battery voltage falls
below an internal threshold, and enters a
low-quiescent current sleep mode when the input
voltage falls below the battery voltage.
The bq24171 features Dynamic Power Management
(DPM) to reduce the charge current when the input
power limit is reached to avoid over-loading the
adapter. A highly-accurate current-sense amplifier
enables precise measurement of input current from
adapter to monitor overall system power.
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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