SLUSBB3E December   2013  – January 2016

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configurations and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Supply Current
    6. 7.6  Digital Input and Output DC Characteristics
    7. 7.7  LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics
    8. 7.8  ADC (Temperature and Cell Measurement) Characteristics
    9. 7.9  I2C-Compatible Interface Communication Timing Characteristics
    10. 7.10 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 Data Commands
        1. 8.4.1.1 Standard Data Commands
        2. 8.4.1.2 Control(): 0x00 and 0x01
      2. 8.4.2 Alternate Chemistry Selection
      3. 8.4.3 Communications
        1. 8.4.3.1 I2C Interface
        2. 8.4.3.2 I2C Time Out
        3. 8.4.3.3 I2C Command Waiting Time
        4. 8.4.3.4 I2C Clock Stretching
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 BAT Voltage Sense Input
        2. 9.2.2.2 Integrated LDO Capacitor
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YZF|9
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

The Texas Instruments bq27621-G1 fuel gauge accurately predicts the battery capacity and other operational characteristics of a single Li-base rechargeable cell.

9.2 Typical Application

bq27621-G1 Replace_Fig6_sch_SLUUAM6.gif Figure 9. Reference (EVM) Schematic

9.2.1 Design Requirements

The bq27621-G1 fuel gauge is predefined for LiCoO2-based batteries, which have 4.2-V, 4.3-V, and 4.35-V maximum charging voltages. One orderable part number contains three different battery profiles, which can be selected using I2C commands. Please refer to the bq27621-G1 Technical Reference Manual (SLUUAD4) for the procedure to select alternate chemistry profiles.

9.2.2 Detailed Design Procedure

9.2.2.1 BAT Voltage Sense Input

A ceramic capacitor at the input to the BAT pin is used to bypass AC voltage ripple to ground, greatly reducing its influence on battery voltage measurements. It proves most effective in applications with load profiles that exhibit high-frequency current pulses (that is, cell phones) but is recommended for use in all applications to reduce noise on this sensitive high-impedance measurement node.

9.2.2.2 Integrated LDO Capacitor

The fuel gauge has an integrated LDO with an output on the VDD pin of approximately 1.8 V. A capacitor of value at least 0.47 μF should be connected between the VDD pin and VSS. The capacitor should be placed close to the gauge IC and have short traces to both the VDD pin and VSS.

9.2.3 Application Curves

bq27621-G1 D001_SLUSBH1.gif Figure 10. Voltage Accuracy
bq27621-G1 D002_SLUSBH1.gif Figure 12. Current Accuracy
bq27621-G1 D003_SLUSBH1.gif Figure 11. Temperature Accuracy