bq24170
bq24172
www.ti.com
SLUSAD2B –NOVEMBER 2010–REVISED APRIL 2011
1.6-MHz Synchronous Switch-Mode Li-Ion and Li-Polymer Stand-Alone Battery Charger
with Integrated MOSFETs and Power Path Selector
Check for Samples: bq24170, bq24172
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FEATURES
APPLICATIONS
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1.6MHz Synchronous Switch-Mode Charger
with 4A Integrated N-MOSFETs
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Tablet PC
Netbook and Ultra-Mobile Computers
Portable Data Capture Terminals
Portable Printers
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Up to 94% Efficiency
30V Input Rating with Adjustable Over-Voltage
Protection
Medical Diagnostics Equipment
Battery Bay Chargers
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4.5V to 17V Input Operating Voltage Range
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Battery Charge Voltage
Battery Back-Up Systems
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bq24170: 1, 2, or 3-Cell with 4.2V/Cell
bq24172: Adjustable Charge Voltage
DESCRIPTION
The bq24170/172 is highly integrated stand-alone
Li-ion and Li-polymer switch-mode battery charger
with two integrated N-channel power MOSFETs. It
High Integration
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Automatic Power Path Selector Between
Adapter and Battery
offers
a
constant-frequency synchronous PWM
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Dynamic Power Management
Integrated 20-V Switching MOSFETs
Integrated Bootstrap Diode
Internal Loop Compensation
Internal Digital Soft Start
controller with high accuracy regulation of input
current, charge current, and voltage. It closely
monitors the battery pack temperature to allow
charge only in a preset temperature window. 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.
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Safety
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Thermal Regulation Loop Throttles Back
Current to Limit Tj = 120°C
The bq24170/172 charges the battery in three
phases: precondictioning, constant current, and
constant voltage. The bq24170 charges one, two, or
three cells (selected by CELL pin), and the bq24172
is adjustable for up to three series Li+ cells.
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Thermal Shutdown
Battery Thermistor Sense Hot/Cold Charge
Suspend & Battery Detect
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Input Over-Voltage Protection with
Programmable Threshold
Charge is terminated when the current reaches 10%
of the fast charge rate. A programmable charge timer
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Cycle-by-Cycle Current Limit
offers
a
safety back up. The bq24170/172
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Accuracy
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.
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±0.5% Charge Voltage Regulation
±4% Charge Current Regulation
±4% Input Current Regulation
The
bq24170/172
features
Dynamic
Power
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Less than 15μA Battery Current with Adapter
Removed
Management (DPM) to reduce the charge current
when the input power limit is reached to avoid
over-loading the adapter.
current-sense amplifier enables precise measurement
of input current from adapter to monitor overall
system power.
Less than 1.5mA Input Current with Adapter
Present and Charge Disabled
A
highly-accurate
Small QFN Package
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3.5mm × 5.5mm QFN-24 Pin
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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 © 2010–2011, Texas Instruments Incorporated