MAX1687

LAST TIME BUY

Step-Up DC-DC Converters with Precise, Adaptive Current Limit for GSM

Reduces GSM Battery Peak Current by 6x, Eliminates DC-DC Noise during Transmission with User Selectable Disable

Data Sheet (Rev. 0) Product Selection Table
Viewing:

Overview

  • Low 450mA Peak Battery Current Provides 2A, 5V GSM Burst
  • 90% Efficiency
  • Internal Power MOSFETs and Current-Sense Resistor
  • Output Disconnects from Input During Shutdown
  • 3µA Shutdown Current
  • Precise Voltage-Controlled Current Limit (MAX1687)
  • Adaptive Constant-Recharge-Time Capability (MAX1688)
  • 1.25V to 6V Adjustable Output
  • 2.7V to 6V Input Range (1 Li-Ion cell or 3 NiMH cells)
  • Switching Frequency Can Exceed 1MHz
  • Standby Mode Disables DC-DC During Transmission Burst
  • Low Inrush Current at Start-Up

The MAX1687/MAX1688 step-up DC-DC converters deliver up to 2W from a single Li-Ion or three NiMH cells. The devices are ideal for burst-load applications such as GSM cell phones and wireless LANs, where the RF power amplifiers require short, high current bursts. The MAX1687/MAX1688 reduce battery surge current by slowly charging a reservoir capacitor, which supplies the necessary peak energy for the load current burst. As a result, the peak battery current is limited, thus maximizing battery life and minimizing battery voltage sag and transient dips.

An internal synchronous rectifier provides over 90% conversion efficiency and eliminates the need for an external Schottky diode. A logic shutdown mode reduces the shutdown current to only 3µA. The devices can be disabled during current bursts (RF transmit mode) to eliminate switching noise.

The switching frequency of the MAX1687/MAX1688, controlled by the selected inductor, can exceed 1MHz. Two external resistors set the output voltage from 1.25V to 6V. The MAX1687 controls peak battery current, while the MAX1688 features a more advanced, adaptive constant-recharge-time algorithm that maximizes battery life. The MAX1687/MAX1688 are available in thin 16-pin TSSOP (1.1mm max height) or standard 8-pin SO packages.

Applications

  • GSM Phones
  • PC Cards (PCMCIA)
  • Wireless Handsets
MAX1687
Step-Up DC-DC Converters with Precise, Adaptive Current Limit for GSM
MAX1687, MAX1688: Typical Operating Circuit
Add to myAnalog

Add product to the Products section of myAnalog (to receive notifications), to an existing project or to a new project.

Create New Project
Ask a Question

Documentation

Data Sheet 1

Reliability Data 1

Technical Articles 2

Learn More
Add to myAnalog

Add media to the Resources section of myAnalog, to an existing project or to a new project.

Create New Project

Software Resources

Can't find the software or driver you need?

Request a Driver/Software

Evaluation Kits

MAX1688EVKIT

Evaluation Kit for the MAX1687, MAX1688

Buy Now View Details

Features and Benefits

  • 2.7V to 6V Input Voltage Range
  • 5V Output Voltage
  • Less than 500mV Output Voltage Droop with 1.42A Burst Current
  • 90% Efficiency
  • Output Disconnected from Input during Shutdown
  • 600kHz Switching Frequency
  • Internal MOSFET and Synchronous Rectifier
  • 3µA IC Shutdown Current
  • Surface-Mount Components (TSSOP Package)
  • Fully Assembled and Tested

Product Details

The MAX1688 evaluation kit (EV kit) is a boost switching regulator for one Li-Ion cell or three NiCd/NiMH cells in battery-powered systems. The EV kit accepts a positive input between 2.7V and 6V and converts it to a 5V output. It can easily deliver the current burst required for cell-phone power amplifier systems. The MAX1688 reduces battery surge current by slowly charging a reservoir capacitor, which supplies the necessary peak energy for the current burst. As a result, the peak battery input current is limited, thereby minimizing the battery voltage sag and transient dips. The EV kit operates at 600kHz, allowing the use of small external components.

The MAX1688 EV kit provides low quiescent current and high efficiency for maximum battery life. An internal synchronous rectifier is used to provide over 90% conversion efficiency. This EV kit is a fully assembled and tested surface-mount circuit board. The MAX1688 EV kit can also be used to evaluate the MAX1687.

Applications

  • GSM Phones
  • PC Cards (PCMCIA)
  • Wireless Handsets

MAX1687EVKIT

Evaluation Kit for the MAX1687, MAX1688

Buy Now View Details

Features and Benefits

  • 2.7V to 6V Input Voltage Range
  • 5V Output Voltage
  • Less than 500mV Output Voltage Droop with 1.42A Burst Current
  • 90% Efficiency
  • Output Disconnected from Input during Shutdown
  • 600kHz Switching Frequency
  • Internal MOSFET and Synchronous Rectifier
  • 3µA IC Shutdown Current
  • Surface-Mount Components (TSSOP Package)
  • Fully Assembled and Tested

Product Details

The MAX1688 evaluation kit (EV kit) is a boost switching regulator for one Li-Ion cell or three NiCd/NiMH cells in battery-powered systems. The EV kit accepts a positive input between 2.7V and 6V and converts it to a 5V output. It can easily deliver the current burst required for cell-phone power amplifier systems. The MAX1688 reduces battery surge current by slowly charging a reservoir capacitor, which supplies the necessary peak energy for the current burst. As a result, the peak battery input current is limited, thereby minimizing the battery voltage sag and transient dips. The EV kit operates at 600kHz, allowing the use of small external components.

The MAX1688 EV kit provides low quiescent current and high efficiency for maximum battery life. An internal synchronous rectifier is used to provide over 90% conversion efficiency. This EV kit is a fully assembled and tested surface-mount circuit board. The MAX1688 EV kit can also be used to evaluate the MAX1687.

Applications

  • GSM Phones
  • PC Cards (PCMCIA)
  • Wireless Handsets
MAX1688EVKIT
Evaluation Kit for the MAX1687, MAX1688
MAX1687EVKIT
Evaluation Kit for the MAX1687, MAX1688

Latest Discussions

No discussions on MAX1687 yet. Have something to say?

Start a Discussion on EngineerZone®

Recently Viewed