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SMBus Level 2 Battery Charger with Remote Sense

Low-Cost SMBus™ Charger with Integrated Dual n-Channel FET Drivers Deliver Up to 8A Charge Current

Product Details

Key Features

Simplified Block Diagram

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Key Features

  • 0.5% Battery Voltage Accuracy
  • 3% Input Current-Limit Accuracy
  • 3% Charge-Current Accuracy
  • SMBus 2-Wire Serial Interface
  • Cycle-by-Cycle Current Limit
    • Battery Short-Circuit Protection
    • Fast Response for Pulse Charging
    • Fast System-Load-Transient Response
  • Dual-Remote-Sense Inputs
  • Monitor Outputs for
    • Adapter Current (4% Accuracy)
    • AC Adapter Detection
  • 11-Bit Battery Voltage Setting
  • 6-Bit Charge-Current/Input-Current Setting
  • 8A (max) Battery Charger Current
  • 11A (max) Input Current
  • +8V to +26V Input Voltage Range
  • Charges Li+, NiMH, and NiCd Battery Chemistries

Applications/Uses

  • Medical Devices
  • Notebook Computers
  • Portable Equipment with Rechargeable Batteries
  • Tablet PCs

Description

The MAX8731 is an SMBus™ programmable multichemistry battery charger. The MAX8731 uses a minimal command set to easily program the charge voltage, charge current, and adapter current limit.

The MAX8731 charges one to four Li+ series cells and delivers up to 8A charge current. The MAX8731 drives n-channel MOSFETs for improved efficiency and reduced cost. Low-offset current-sense amplifiers provide high accuracy with 10mΩ sense resistors.

The MAX8731 current-sense amplifiers provide high accuracy (3% at 3.5A) and also provide fast cycle-by-cycle current-mode control to protect against battery short circuit and system load transients.

The charger employs dual remote-sense, which reduces charge time by measuring the feedback voltage directly at the battery, improving accuracy of initial transition into constant-voltage mode. The MAX8731 provides 0.5% battery voltage accuracy directly at the battery terminal.

The MAX8731 provides a digital output that indicates the presence of the AC adapter, as well as an analog output that indicates the adapter current within 4% accuracy.

The MAX8731 is available in a small 5mm x 5mm, 28-pin, thin (0.8mm) QFN package. An evaluation kit is available to reduce design time. The MAX8731 is available in lead-free packages.

Simplified Block Diagram

MAX8731: Typical Operating Circuit MAX8731: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Sampling:
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.