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Li-Ion Chargers with Smart Power Selector, Adapter Type Detection, and USB Enumeration

Industry's First Charger to Detect Adapter Type and Enumerate Autonomously

Product Details

The MAX8895_ USB-compliant linear battery chargers operate from either a USB port or dedicated charger with automatic detection of adapter type and USB enumeration capability. The MAX8895X/MAX8895Y integrate the battery disconnect switch, current-sense circuit, MOSFET pass elements, and thermal regulation circuitry, and eliminate the external reverse-blocking Schottky diode to create the simplest and smallest stand-alone charging solutions.

The MAX8895_ include an automated detection of charge adapter type, making it possible to distinguish between USB 2.0 device, USB charger, and dedicated charger devices. Furthermore, the MAX8895X/MAX8895Y include a USB enumeration function that automatically negotiates with a USB host, making it possible to achieve the highest current available from a USB 2.0 device or USB charger without processor intervention. The adapter type detection is compliant with USB 2.0 specification as well as USB charging Revision 1.1.

The MAX8895_ control the charging sequence for single-cell Li+ batteries from initial power-OK indication, through prequalification, fast-charge, top-off, and finally charge termination. Charging is controlled using constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation for safe operation under all conditions. The maximum charging current is adaptively controlled by subtracting the system current from the input current limit, ensuring that the charging current is always maximized for any given operating condition.

The MAX8895_ feature optimized smart power control to make the best use of limited USB or adapter power. Battery charge current is set independently of the SYS_ input current limit. Power not used by the system charges the battery. Automatic input selection switches the system from battery to external power. This allows the application to operate without a battery, discharged battery, or dead battery.

Other features include undervoltage lockout (UVLO), overvoltage protection (OVP), charge status flag, charge fault flag, power-OK monitor, battery thermistor monitor, charge timer, and a 3.3V output.

The MAX8895_ operate from a +4.0V to +6.6V supply and include overvoltage protection up to +16V. The MAX8895_ are specified over the extended temperature range (-40°C to +85°C) and are available in a compact 2.36mm x 2.36mm, 25-bump WLP package (0.4mm pitch).

Key Features

  • Enables Charging from a USB Port*
  • Automatic Detection of Adapter Type
  • Enumeration Capability Without Processor Intervention
  • USB Low-Speed Operation Without External Crystal (MAX8895V/MAX8895W/MAX8895X)
  • USB Full-Speed Operation Using an External Crystal (MAX8895Y)
  • Compliant with USB 2.0 Specification
  • Compliant with USB Charging Specification (Revision 1.1)
  • Adaptive Input Current Limit for Dedicated Charger
  • Input Overvoltage Protection to 16V
  • Automatic Current Sharing Between Battery Charging and System
  • Smart Power Selector™ Allows Operation with Discharged or No Battery
  • NTC Monitoring of Battery Temperature
  • No External MOSFETs Required
  • Thermal Regulation Prevents Overheating
  • 2µA Shutdown Current
  • Tiny 2.36mm x 2.36mm, 25-Bump, 0.4mm Pitch WLP Package

Applications/Uses

  • Bluetooth® Headsets
  • Charging Cradles
  • Portable Devices
Parametric specs for Battery Chargers
Charging VIN (V) (max) 6.6
Max. ICHG (A) 1.85
Cell Chemistry Li-Ion
Li-Polymer
# Lithium Ion Cells 1
Protected VIN (V) (max) 14
Charger (V) 4.2
Oper. Temp. (°C) -40 to +85
Package/Pins WLP/25
Budgetary
Price (See Notes)
-
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Technical Docs

Design & Development

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Description

The MAX8895 evaluation kit (EV kit) is a fully assembled and tested PCB for evaluating the MAX8895_ dual-path lithium-ion (Li+) battery chargers. The EV kit is powered from a USB port or dedicated charger with automatic detection of adapter type and USB enumeration capability.

The EV kit features LED indicators for charging (active-low CHG), prequalification state (active-low PREQ), power-ok (active-low UOK), and fault condition (active-low FLT). The LEDs can be powered from SYS, BAT+, or BUS through an external LDO. The EV kit also features programmable charging currents (JU1, JU2), NTC thermistor for thermal protection (R11), and logic switches for the MAX8895_ features (SW1, SW2).

By default, the EV kit is configured for the MAX8895Y, but can also be reconfigured for the MAX8895W/MAX8895X with slight board/hardware modifications. To evaluate the MAX8895W/MAX8895X, request free samples of the MAX8895WEWA+/MAX8895XEWA+ when ordering the EV kit and see the Evaluating the MAX8895W/MAX8895X in the full data sheet section.

View Details

Features

  • Micro-B USB Connector
  • Dual-Speed Operation (Full Speed: MAX8895Y; Low Speed: MAX8895W/MAX8895X)
  • Input Overvoltage Protection to 16V
  • Automatic Current Sharing Between Battery Charging and System
  • Smart Power Selector Operates with Discharged or No Battery
  • LED Indicators
  • Logic Switches
  • NTC Monitoring of Battery Temperature
  • Thermal Regulation Prevents Overheating

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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.

Parameters

Parametric specs for Battery Chargers
Charging VIN (V) (max) 6.6
Max. ICHG (A) 1.85
Cell Chemistry Li-Ion
Li-Polymer
# Lithium Ion Cells 1
Protected VIN (V) (max) 14
Charger (V) 4.2
Oper. Temp. (°C) -40 to +85
Package/Pins WLP/25
Budgetary
Price (See Notes)
-

Key Features

  • Enables Charging from a USB Port*
  • Automatic Detection of Adapter Type
  • Enumeration Capability Without Processor Intervention
  • USB Low-Speed Operation Without External Crystal (MAX8895V/MAX8895W/MAX8895X)
  • USB Full-Speed Operation Using an External Crystal (MAX8895Y)
  • Compliant with USB 2.0 Specification
  • Compliant with USB Charging Specification (Revision 1.1)
  • Adaptive Input Current Limit for Dedicated Charger
  • Input Overvoltage Protection to 16V
  • Automatic Current Sharing Between Battery Charging and System
  • Smart Power Selector™ Allows Operation with Discharged or No Battery
  • NTC Monitoring of Battery Temperature
  • No External MOSFETs Required
  • Thermal Regulation Prevents Overheating
  • 2µA Shutdown Current
  • Tiny 2.36mm x 2.36mm, 25-Bump, 0.4mm Pitch WLP Package

Applications/Uses

  • Bluetooth® Headsets
  • Charging Cradles
  • Portable Devices

Description

The MAX8895_ USB-compliant linear battery chargers operate from either a USB port or dedicated charger with automatic detection of adapter type and USB enumeration capability. The MAX8895X/MAX8895Y integrate the battery disconnect switch, current-sense circuit, MOSFET pass elements, and thermal regulation circuitry, and eliminate the external reverse-blocking Schottky diode to create the simplest and smallest stand-alone charging solutions.

The MAX8895_ include an automated detection of charge adapter type, making it possible to distinguish between USB 2.0 device, USB charger, and dedicated charger devices. Furthermore, the MAX8895X/MAX8895Y include a USB enumeration function that automatically negotiates with a USB host, making it possible to achieve the highest current available from a USB 2.0 device or USB charger without processor intervention. The adapter type detection is compliant with USB 2.0 specification as well as USB charging Revision 1.1.

The MAX8895_ control the charging sequence for single-cell Li+ batteries from initial power-OK indication, through prequalification, fast-charge, top-off, and finally charge termination. Charging is controlled using constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation for safe operation under all conditions. The maximum charging current is adaptively controlled by subtracting the system current from the input current limit, ensuring that the charging current is always maximized for any given operating condition.

The MAX8895_ feature optimized smart power control to make the best use of limited USB or adapter power. Battery charge current is set independently of the SYS_ input current limit. Power not used by the system charges the battery. Automatic input selection switches the system from battery to external power. This allows the application to operate without a battery, discharged battery, or dead battery.

Other features include undervoltage lockout (UVLO), overvoltage protection (OVP), charge status flag, charge fault flag, power-OK monitor, battery thermistor monitor, charge timer, and a 3.3V output.

The MAX8895_ operate from a +4.0V to +6.6V supply and include overvoltage protection up to +16V. The MAX8895_ are specified over the extended temperature range (-40°C to +85°C) and are available in a compact 2.36mm x 2.36mm, 25-bump WLP package (0.4mm pitch).

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.