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Product details

Parameters

Number of series cells 1, 2, 3, 4 Charge current (Max) (A) 8 Operating Vin (Max) (V) 24 Cell chemistry Li-Ion/Li-Polymer Battery charge voltage (Min) (V) 1.024 Battery charge voltage (Max) (V) 19.2 Absolute Vin (safety rating) (Max) ((V)) 30 Control topology Switch-Mode Buck Control interface SMBus Features Input OVP Operating Vin (Min) (V) 4.5 Rating Catalog open-in-new Find other Battery charger ICs

Package | Pins | Size

VQFN (RGR) 20 12 mm² 3.5 x 3.5 open-in-new Find other Battery charger ICs

Features

  • Adapter and Battery Provide Power to System
    Together to Support Intel® CPU Turbo Boost
    Mode
  • SMBus Host-Controlled NMOS-NMOS
    Synchronous Buck Converter With Programmable
    615-, 750-, and 885-kHz Switching Frequencies
  • Automatic N-Channel MOSFET Selection of
    System Power Source From Adapter or Battery
    Driven by Internal Charge Pumps
  • Enhanced Safety Features for Overvoltage
    Protection, Overcurrent Protection, Battery,
    Inductor and MOSFET Short-Circuit Protection
  • Programmable Input Current, Charge Voltage,
    Charge Current Limits
    • ±0.5% Charge Voltage Accuracy up to 19.2 V
    • ±3% Charge Current Accuracy up to 8.128 A
    • ±3% Input Current Accuracy up to 8.064 A
    • ±2% 20× Adapter Current or Charge Current
      Amplifier Output Accuracy
  • Programmable Battery Depletion Threshold, and
    Battery LEARN Function
  • Programmable Adapter Detection and Indicator
  • Integrated Loop Compensation and Soft Start
  • Real-Time System Control on ILIM Pin to Limit
    Charge Current
  • AC Adapter Operating Range: 4.5 V to 24 V
  • 5-µA Off-State Battery Discharge Current
  • 0.65 mA (0.8 mA Max) Adapter Standby
    Quiescent Current
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Description

The bq24735 device is a high-efficiency, synchronous battery charger, offering low component count for space-constrained, multichemistry battery charging applications. The bq24735 device supports turbo boost by allowing battery discharge energy to the system when system power demand is temporarily higher than the adapter maximum power level so the adapter will not crash.

The bq24735 device uses two charge pumps to separately drive N-channel MOSFETs (ACFET, RBFET, and BATFET) for automatic system power source selection.

SMBus controlled input current, charge current, and charge voltage digital-to-analog converters (DACs) allow for very high-regulation accuracies that can be easily programmed by the system power management microcontroller.

The bq24735 device uses an internal input current register or an external ILIM pin to throttle down PWM modulation to reduce the charge current. The bq24735 device charges 1-, 2-, 3-, or 4-series Li+ cells.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 8
Type Title Date
* Datasheet bq24735 1- to 4-Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode With N-Channel Power MOSFET Selector datasheet (Rev. B) Apr. 29, 2015
Technical articles When to use rechargeable batteries in small battery applications Oct. 01, 2019
Technical articles Understanding battery charger features and charging topologies Sep. 19, 2016
Technical articles Should I use a linear charger or a switching charger? Oct. 30, 2015
Technical articles Summertime and the livin' is easy Jun. 20, 2014
Application note 1Q 2012 Issue Analog Applications Journal Jan. 31, 2012
Application note Turbo boost charger supports CPU turbo mode Jan. 31, 2012
User guide bq24735/725A Battery Charger Evaluation Module (Rev. A) Aug. 16, 2011

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

EVALUATION BOARD Download
49
Description

The BQ24735EVM-710 evaluation module (EVM) is a complete charger module for evaluating a multicell synchronous notebook turbo boost charge using the bq24735 devices. It is designed to deliver up to 4 A of charge current to Li-ion or Li-polymer applications. The charge current is programmable by (...)

Features
  • Evaluation module for bq24735
  • bq24735 adapter and battery together provide power to system to support Intel™ CPU Turbo Boost mode
  • High-efficiency NMOS-NMOS synchronous buck charger with 750-kHz frequency
  • High-efficiency and low-cost NMOS power path selector and integrated gate driver
  • User-selectable (...)

Software development

DRIVER OR LIBRARY Download
Linux Driver for BQ24735
BQ24735SW-LINUX The Linux driver supports the BQ24735 1-4 Cell Li+ Battery Charge Controller. The Linux driver supports communication through the I2C bus and interfaces with the power supply sub-system.

 

Linux Mainline Status

Available in Linux Main line: Yes
Available through git.ti.com: N/A

Supported Devices:

  • bq24735

 

(...)

GUI FOR EVALUATION MODULE (EVM) Download
SLUC258A.ZIP (2259 KB)

Design tools & simulation

CALCULATION TOOL Download
SLUC203A.ZIP (394 KB)

Reference designs

REFERENCE DESIGNS Download
1-4 Cell Li+ Battery SMBus Charge Controller Reference Design
TIDA-00039 This reference design is a complete charger module for evaluating a multi-cell synchronous notebook turbo boost charge using the bq24735 devices. It is designed to deliver up to 4 A of charge current to Li-ion or Li-polymer applications. The charge current is programmable by SMBus interface through (...)
document-generic Schematic

CAD/CAE symbols

Package Pins Download
VQFN (RGR) 20 View options

Ordering & quality

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  • MSL rating/Peak reflow
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  • Qualification summary
  • Ongoing reliability monitoring

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