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Smart Battery Monitor

Product Details

The DS2438 remains in production, however, for new projects, we recommend ModelGauge m5 MAX17215 fuel gauge.

The DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack: a means of tagging a battery pack with a unique serial number, a direct-to-digital temperature sensor which eliminates the need for thermistors in the battery pack, an A/D converter which measures the battery voltage and current, an integrated current accumulator which keeps a running total of all current going into and out of the battery, an elapsed time meter, and 40 bytes of nonvolatile EEPROM memory for storage of important parameters such as battery chemistry, battery capacity, charging methodology and assembly date. Information is sent to/from the DS2438 over a 1-Wire® interface, so that only one wire (and ground) needs to be connected from a central microprocessor to a DS2438. This means that battery packs need only have three output connectors: battery power, ground, and the 1-Wire interface.

Because each DS2438 contains a unique silicon serial number, multiple DS2438s can exist on the same 1-Wire bus. This allows multiple battery packs to be charged or used in the system simultaneously.

Applications for the smart battery monitor include portable computers, portable/cellular telephones, and handheld instrumentation battery packs in which it is critical to monitor real-time battery performance. Used in conjunction with a microcontroller in the host system, the DS2438 provides a complete smart battery pack solution that is fully chemistry-independent. The customization for a particular battery chemistry and capacity is realized in the code programmed into the microcontroller and DS2438 EEPROM, and only a software revision is necessary should a designer wish to change battery pack chemistry.

Key Features

  • Unique 1-Wire interface requires only one port pin for communication
  • Provides unique 64-bit serial number to battery packs
  • Eliminates thermistors by sensing battery temperature on-chip
  • On-board A/D converter allows monitoring of battery voltage for end-of-charge and end-of-discharge determination
  • On-board integrated current accumulator facilitates fuel gauging
  • Elapsed time meter in binary format
  • 40-byte nonvolatile user memory available for storage of battery-specific data
  • Operating range -40°C to +85°C

Applications/Uses

  • Cell Phones
  • Digital Still Cameras
  • Digital Video Cameras
  • Palmtops, Handy Terminals (incl. barcode)
  • Pen Entry Palmtops, PDAs and Organizers
  • Smart Battery Packs/Chargers
Parametric specs for Battery Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Status Monitor
Battery Type 1-2 Cell Li-Ion
2-6 Cell NiMH
Interface 1-Wire
User Data Storage (Bytes) 40 EEPROM
Parameters Measured Current
Temperature
Time
Voltage
Applications Pack
VSUPPLY (V) (min) 2.4
VSUPPLY (V) (max) 10
Package/Pins SOIC (N)/8
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
$2.73 @1k
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Simplified Block Diagram

DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack | Block Diagram DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack | Block Diagram Zoom icon

Design & Development

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Description

The DS2438 evaluation kit (EV kit) makes performance evaluation, software development, and prototyping with the DS2438 smart battery monitor easy. The evaluation board interfaces to a PC through a DS9123O USB adapter and RJ-11 cable connection. All related data sheets can be found on our website at www.maximintegrated.com.

Several jacks on the board allow easy connection to bench power supplies and to the serial port of a PC. The ZIF socket supports multiple parts.

The included software enables low-volume device programming with a real-time display of the temperature, voltage, current, accumulated current, and elapsed time measurements. In addition, the user can calibrate current measurements using the DS2438's offset calibration register and other features.

View Details

Features

  • Demonstrates the Capabilities of the DS2438 Smart Battery Monitor, Including:
    • Temperature Measurement
    • Voltage Measurement
    • Current Measurement
    • Current Accumulation
    • Elapsed Time
    • Information Storage
    • Identification
  • Provides Small-Volume DS2438 Programming Support
  • Interfaces to the USB Port of a PC Running Windows XP® or Older Operating System

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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 Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Status Monitor
Battery Type 1-2 Cell Li-Ion
2-6 Cell NiMH
Interface 1-Wire
User Data Storage (Bytes) 40 EEPROM
Parameters Measured Current
Temperature
Time
Voltage
Applications Pack
VSUPPLY (V) (min) 2.4
VSUPPLY (V) (max) 10
Package/Pins SOIC (N)/8
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
$2.73 @1k

Key Features

  • Unique 1-Wire interface requires only one port pin for communication
  • Provides unique 64-bit serial number to battery packs
  • Eliminates thermistors by sensing battery temperature on-chip
  • On-board A/D converter allows monitoring of battery voltage for end-of-charge and end-of-discharge determination
  • On-board integrated current accumulator facilitates fuel gauging
  • Elapsed time meter in binary format
  • 40-byte nonvolatile user memory available for storage of battery-specific data
  • Operating range -40°C to +85°C

Applications/Uses

  • Cell Phones
  • Digital Still Cameras
  • Digital Video Cameras
  • Palmtops, Handy Terminals (incl. barcode)
  • Pen Entry Palmtops, PDAs and Organizers
  • Smart Battery Packs/Chargers

Description

The DS2438 remains in production, however, for new projects, we recommend ModelGauge m5 MAX17215 fuel gauge.

The DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack: a means of tagging a battery pack with a unique serial number, a direct-to-digital temperature sensor which eliminates the need for thermistors in the battery pack, an A/D converter which measures the battery voltage and current, an integrated current accumulator which keeps a running total of all current going into and out of the battery, an elapsed time meter, and 40 bytes of nonvolatile EEPROM memory for storage of important parameters such as battery chemistry, battery capacity, charging methodology and assembly date. Information is sent to/from the DS2438 over a 1-Wire® interface, so that only one wire (and ground) needs to be connected from a central microprocessor to a DS2438. This means that battery packs need only have three output connectors: battery power, ground, and the 1-Wire interface.

Because each DS2438 contains a unique silicon serial number, multiple DS2438s can exist on the same 1-Wire bus. This allows multiple battery packs to be charged or used in the system simultaneously.

Applications for the smart battery monitor include portable computers, portable/cellular telephones, and handheld instrumentation battery packs in which it is critical to monitor real-time battery performance. Used in conjunction with a microcontroller in the host system, the DS2438 provides a complete smart battery pack solution that is fully chemistry-independent. The customization for a particular battery chemistry and capacity is realized in the code programmed into the microcontroller and DS2438 EEPROM, and only a software revision is necessary should a designer wish to change battery pack chemistry.

Simplified Block Diagram

DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack | Block Diagram DS2438 smart battery monitor provides several functions that are desirable to carry in a battery pack | Block Diagram Zoom icon

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