BQ24170 Datasheet, PDF (1/35 Pages) Texas Instruments – 1.6-MHz Synchronous Switch-Mode Li-Ion and Li-Polymer Stand-Alone Battery Charger

bq24170
bq24172
www.ti.com
SLUSAD2A – NOVEMBER 2010 – REVISED NOVEMBER 2010
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
FEATURES
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• 1.6MHz Synchronous Switch-Mode Charger
with 4A Integrated N-MOSFETs
• Up to 94% Efficiency
• 4.5V–17V Input Operating Range
• Battery Charge Voltage
– bq24170: 1, 2, or 3-Cell with 4.2V/Cell
– bq24172: Adjustable Charge Voltage
• 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 15mA 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 bq24170/172 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 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.
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.
Charge is terminated when the current reaches 10%
of the fast charge rate. A programmable charge timer
offers a safety back up. The bq24170/172
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 bq24170/172 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 © 2010, Texas Instruments Incorporated