Industry's Smallest 1.55A 1-Cell Li+ DC-DC Charger

Switching Charger Delivers High Efficiency (90%~92%)


The MAX8971 is a compact, high-frequency, high-efficiency switch-mode charger for a one-cell lithium-ion (Li+) battery. It delivers up to 1.55A of current to the battery from inputs up to 7.5V and withstands transient inputs up to 22V. The 4MHz switch-mode charger is ideally suited for small portable devices, such as headsets and ultra-portable media players. It minimizes component size and heat.

Battery-protection features include: low-voltage prequalification, charge fault timer, die temperature monitoring, and battery temperature monitoring. The battery temperature monitoring adjusts the charge current and termination voltage for safe use of secondary lithium-ion batteries.

The IC accepts either a general DC input or USB. It has programmable automatic input-current limiting to protect upstream charging sources such as USB.

Charge parameters are easily adjustable through an I²C interface. Charge is terminated based on user-selectable minimum current level. A safety timer with reset control provides a safety backup for I²C interface. Charge status is provided to the application processor through an interrupt pin.

The IC is available in a space-saving, 20-bump, 2.18mm x 1.62mm WLP package.
MAX8971: Simplified Operating Circuit MAX8971: Simplified Operating Circuit Enlarge+

Key Features

  • Switch-Mode Charger
    • High-Efficiency
    • Low Heat
    • Fast Charge Time
  • Small and Simple
  • Precise
    • Up to ±5% Current Regulation and 0.5% Voltage Regulation
  • Safe
    • JEITA Battery Temperature Monitor
    • Over/Undervoltage Protection, Safety Timers, Temperature Regulation
    • USB Friendly
  • Flexible
    • Programmable Voltage/Current
    • Status/Interrupts Through I2C
    • Automatic Input Current Limit
  • I²C Interface
    • Input Current Limit (100mA to 1500mA)
    • Fast-Charge/Termination Current (250mA to 1550mA)
    • Charge Voltage (4.1V, 4.15V, 4.2V, 4.35V)
    • Safety Timer
    • Termination Enable
  • +22V Absolute Maximum Input Voltage Rating
  • Up to 7.5V Maximum Operating Input Voltage
  • 5V USB/Safeout LDO for USB PHY
  • 2.3A GSM RF Test Mode (Factory Testing)
  • Charge Current to Voltage Conversion (VICHG) for Baseband ADC
  • Reverse Battery Leakage Protection
  • Input/Output Overvoltage Protection
  • Interrupt Status Output


  • Digital Cameras
  • GPS, PDAs
  • Headsets and Media Players
  • Smartphones
  • USB Charging
Part Number Lithium Ion Cells Protected VIN
Charging VIN
Charge Rate Set by Max. ICHG
Charge Termination Charge Regulation Oper. Temp.
Package/Pins Budgetary
max max See Notes
MAX8971  1 22 7.5 I2C/SMBus 1.55
Min. Charge Current
Switchmode -40 to +85
$1.19 @1k
See All Battery Chargers (73)
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.

MAX8971EVKIT: Evaluation System for the MAX8971
MAX8971EVMINIQU: Evaluation System for the MAX8971

Quality and Environmental Data

Product Reliability Reports: MAX8971.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Related Resources

Power Management Solution

  • Extend System Battery Use Time
  • Extend Product Shelf-Life
  • Minimize Board Area

7µA 1-Cell Fuel Gauge with ModelGauge m5 EZ

  • ModelGauge m5 EZ
  • Low 7µA Operating Current
  • Wide Sense Resistor Range

USB Detection with Smart Power Selector Li+ Chargers

  • Flexible System Design to Operate with Any USB Charger Source
  • Easy to Implement Li+ Battery Charging
  • Integrates High Level of Protection

USB Detection with Smart Power Selector Li+ Chargers

  • Flexible System Design to Operate with Any USB Charger Source
  • Easy to Implement Li+ Battery Charging
  • Integrates High Level of Protection