MAX8731A

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


Please check latest availability status for a specific part variant.

Description

The MAX8731A is an SMBus™ programmable multi-chemistry battery charger. The MAX8731A uses a minimal command set to easily program the charge voltage, charge current, and adapter current limit.

The MAX8731A charges one to four Li+ series cells and delivers up to 8A charge current. The MAX8731A drives n-channel MOSFETs for improved efficiency and reduced cost. Low-offset current-sense amplifiers provide high accuracy with 10mΩ sense resistors.

The MAX8731A 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 MAX8731A provides 0.5% battery voltage accuracy directly at the battery terminal.

The MAX8731A 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 MAX8731A 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 MAX8731A is available in a lead-free package.
MAX8731A: Typical Operating Circuit MAX8731A: Typical Operating Circuit Enlarge+

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

See parametric specs for Battery Chargers (74)


Part NumberLithium Ion CellsProtected VIN
(V)
Charging VIN
(V)
Charge Rate Set byMax. ICHG
(A)
Charge TerminationCharge RegulationOper. Temp.
(°C)
Package/PinsBudgetary
Price
maxmaxSee Notes
MAX8731A 
1
2
3
4
2626I2C/SMBus8
Current Limit
Max. Voltage
Smart Battery Control
Switchmode-40 to +85
TQFN/28
$7.54 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX8731AEVKIT: Evaluation Kit/Evaluation System for the MAX8731A
Product Reliability Reports: MAX8731A.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

 
Status:
Package:
Temperature:

Related Resources


MAX17701
4.5V to 60V, Synchronous Step-Down Supercapacitor Charger Controller

  • Optimized Feature Set for Supercapacitor Charging
  • Reliable Operation in Adverse Environmental Conditions

MAX77751
3.15A USB Type-C Autonomous Charger for 1-Cell Li+ Batteries

  • Up to 16V Protection
  • 13.7V Maximum Input Operating Voltage
  • 3.15A Maximum Charging Current

MAX77962
23VIN 3.2AOUT USB-C Buck-Boost Charger with Integrated FETs for 2S Li-Ion Batteries

  • 3.5V to 23V Input Operating Range, 30VDC Withstand Voltage
  • Reverse Leakage Protection
  • 50mA to 3.15A Programmable Input Current Limit

MAX17320
2S-4S ModelGauge m5 EZ Fuel Gauge with Protector, Internal Self-Discharge Detection, and SHA-256 Authentication

  • Battery Health + Programmable Safety/Protection
  • ModelGauge m5 EZ Algorithm
  • Precision Measurement Without Calibration

MAX17823B
12-Channel High-Voltage Data Acquisition System

  • AEC-Q100 Grade 2 Temperature Range
  • Operating Voltage from 9V to 65V
  • Ultra-Low-Power Operation