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

Delivers 4MHz Switching

Product Details

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.

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

Applications/Uses

  • Mobile Internet Devices
  • PDA, Palmtop, and Wireless Handhelds
  • Personal Navigation Devices
  • Portable Multimedia Players
  • Smart Cell Phones
  • Ultra Mobile PCs

Simplified Block Diagram

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 Zoom icon

Technical Docs

Design & Development

Click any title below to view the detail page where available.

Additional Resources
MAX8903 Inductor Selector Guide

Description

The MAX8903A evaluation kit (EV kit) is a fully assembled and tested circuit board for evaluating the 2A, 1-cell Li+ DC-DC battery charger. The EV kit charges a single-cell lithium-ion (Li+) battery from a DC input (AC adaptor) or a USB 100mA/500mA source and provides system power from the DC input, USB input, or battery. Battery charge current and SYS current limit are independently set. Charge current and DC converter output current limit can be set up to 2A, respectively. The USB input current can be set to 100mA or 500mA and USB suspend mode is also supported. Power not used by the system is available to charge the battery.

The EV kit comes standard with the MAX8903A installed. However, the EV kit can also be used to evaluate the MAX8903B–MAX8903E and MAX8903Y by replacing the MAX8903A (U1) with the preferred IC.

View Details

Features

  • DC-DC Converter Output Current-Limit Adjustment Range of 0.5A to 2A (EV Kit Standard Configuration: 2A)
  • Battery Charger Current-Limit Adjustment Range of 0.5A to 2A (EV Kit Standard Configuration: 1A)
  • USB Current Limit of 100mA or 500mA
  • Efficient 4MHz Switching DC-DC Converter Powers System Load and Charger
  • Instant On—Works with No Battery or Low Battery
  • 28-Pin, 4mm x 4mm Thin QFN Package with Exposed Pad
  • Fully Assembled and Tested

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Support & Training

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Filtered Search

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Parameters

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

Applications/Uses

  • Mobile Internet Devices
  • PDA, Palmtop, and Wireless Handhelds
  • Personal Navigation Devices
  • Portable Multimedia Players
  • Smart Cell Phones
  • Ultra Mobile PCs

Description

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.

Simplified Block Diagram

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 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.