2A 1-Cell Li+ DC-DC Charger for USB and Adapter Power

Delivers 4MHz Switching


The MAX8903A–MAX8903E/MAX8903G/MAX8903H/MAX8903J/MAX8903N/MAX8903Y are integrated 1-cell Li+ chargers and Smart Power Selectors™ with dual (AC adapter and USB) power inputs. The switch mode charger uses a high switching frequency to eliminate heat and allow tiny external components. It can operate with either separate inputs for USB and AC adapter power, or from a single input that accepts both. All power switches for charging and switching the load between battery and external power are included on-chip. No external MOSFETs, blocking diodes, or current-sense resistors are required.

The MAX8903_ feature optimized smart power control to make the best use of limited USB or adapter power. Battery charge current and SYS output current limit are independently set. Power not used by the system charges the battery. Charge current and SYS output current limit can be set up to 2A while USB input current can be set to 100mA or 500mA. Automatic input selection switches the system from battery to external power. The DC input operates from 4.15V to 16V with up to 20V protection, while the USB input has a range of 4.1V to 6.3V with up to 8V protection.

The MAX8903_ internally block current from the battery and system back to the DC and USB inputs when no input supply is present. Other features include prequal charging and timer, fast charge timer, overvoltage protection, charge status and fault outputs, power-OK monitors, and a battery thermistor monitor. In addition, on-chip thermal limiting reduces battery charge rate and AC adapter current to prevent charger overheating. The MAX8903_ is available in a 4mm x 4mm, 28-pin thin QFN package.

The various versions of the MAX8903_ allow for design flexibility to choose key parameters such as system regulation voltage, battery prequalification threshold, and battery regulation voltage. The MAX8903B/MAX8903E/MAX8903G also includes power-enable on battery detection. See the Selector Guide section in the full data sheet for complete details.

MAX8903A: Typical Operating Circuit MAX8677A is an integrated 1-cell Li+ charger and Smart Power Selector™ with dual (DC & USB) power inputs | Typical Operating Circuit Enlarge+

Key Features

  • Efficient DC-DC Converter Eliminates Heat
  • 4MHz Switching for Tiny External Components
  • Instant On—Works with No Battery or Low Battery
  • Dual Current-Limiting Inputs—AC Adapter or USB
    • Automatic Adapter/USB/Battery Switchover to Support Load Transients
    • 50mΩ System-to-Battery Switch
    • Supports USB Spec
  • Thermistor Monitor
  • Integrated Current-Sense Resistor
  • No External MOSFETs or Diodes
  • 4.1V to 16V Input Operating Voltage Range


  • Mobile Internet Devices
  • PDA, Palmtop, and Wireless Handhelds
  • Personal Navigation Devices
  • Portable Multimedia Players
  • Smart Cell Phones
  • Ultra Mobile PCs
Part Number Lithium Ion Cells Protected VIN
Charging VIN
Charge Rate Set by Max. ICHG
Charge Termination Charge Regulation Oper. Temp.
max max
MAX8903  1 20 16
2 Min. Charge Current Switchmode -40 to +85
See Data Sheet
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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.

MAX8903AEVKIT: Evaluation Kit for the MAX8903A, MAX8903B, MAX8903C, MAX8903D, and MAX8903Y
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

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.

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