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

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Status Explanations for product status codes

Active: In Production.

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.
 

Data Sheet

Download this datasheet in PDF formatDownload Rev 0 (PDF, 396kB)
Send this datasheet to any email addressE-Mail
An evaluation kit is available: MAX8731AEVKIT

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
   

Key Specifications:

Battery Chargers
Part Number Cell Chemistry Lithium Ion Cells Protected VIN
(V)
Charging VIN
(V)
Charge Rate Set by Max. ICHG
(A)
Charge Termination Charge Regulation EV Kit Oper. Temp.
(°C)
Package/Pins Smallest Available Pckg.
(mm2)
Budgetary Price
max max max w/pins See Notes
MAX8731A 
Li-Ion
Li-Polymer
1
2
3
4
26 26 SMBus 8
Current Limit
Max. Voltage
Smart Battery Control
Switchmode Yes -40 to +85
TQFN/28
26 $6.26 @1k
See All Battery Chargers (68)
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 prices and delivery, please see the price and availability page or contact an authorized distributor.


Diagram

MAX8731A: Typical Operating Circuit
Typical Operating Circuit

Reliability Reports

Reliability Report: MAX8731A.pdf
Show FIT data for:

Software/Models

none

Ordering Information

Filters: Part Number: Package: Temperature: Tape and Reel Sample
Part Number Free
Sample
Buy Status Explanations for product status codes Package:
TYPE PINS FOOTPRINT
DRAWING  CODE/VAR *
Temp RoHS/Lead-Free?
Materials Analysis
MAX8731AETI+  
Active TQFN;28 pin;26 mm²
Outline Drawing:21-0140 (PDF)
Land Pattern: 90-0026 (PDF)
Use pkgcode/variation: T2855+6*
-40°C to +85°C RoHS/Lead-Free: Lead Free
Materials Analysis
MAX8731AETI+T    
Active TQFN;28 pin;26 mm²
Outline Drawing:21-0140 (PDF)
Land Pattern: 90-0026 (PDF)
Use pkgcode/variation: T2855+6*
-40°C to +85°C RoHS/Lead-Free: Lead Free
Materials Analysis
MAX8731AEVSYS    
Active KIT;

Land Pattern: Not Available

-40°C to +85°C See data sheet

Notes:
  1. Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
  2. Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
  3. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
  4. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Notes and Comments

MAX8731A is a replacement part for MAX8731. MAX8731 is not recommended for new designs.

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Similar Products by Application

Battery Management > Battery Selectors: 1 Li+ Cell Battery Packs (< 4.4V Battery Voltage)
Battery Management > Chargers: 2, 3, and 4 Series Li+ Battery Packs (> 5V Battery Voltage)
Computers: Notebooks > Battery Chargers

Evaluation Kits

MAX8731AEVKIT Evaluation Kit/Evaluation System for the MAX8731A

Products with Similar Part Numbers

MAX8731AEVKIT Evaluation Kit/Evaluation System for the MAX8731A
MAX8731 SMBus Level 2 Battery Charger with Remote Sense


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Information Index

Document Ref.: 19-0767 Rev 0; 2007-03-06
This page last modified: 2009-09-01


 


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