SLUSBB3E December 2013  – January 2016


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configurations and Functions
  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. 7.10Typical Characteristics
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
    4. 8.4Device Functional Modes
      1. 8.4.1Data Commands
        1. Data Commands
        2. Control(): 0x00 and 0x01
      2. 8.4.2Alternate Chemistry Selection
      3. 8.4.3Communications
        1. Interface
        2. Time Out
        3. Command Waiting Time
        4. Clock Stretching
  9. Application and Implementation
    1. 9.1Application Information
    2. 9.2Typical Application
      1. 9.2.1Design Requirements
      2. 9.2.2Detailed Design Procedure
        1. Voltage Sense Input
        2. LDO Capacitor
      3. 9.2.3Application Curves
  10. 10Power Supply Recommendations
    1. 10.1Power Supply Decoupling
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
  12. 12Device and Documentation Support
    1. 12.1Community Resources
    2. 12.2Trademarks
    3. 12.3Electrostatic Discharge Caution
    4. 12.4Glossary
  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
Orderable Information

1 Features

  • Single-Cell Li-Ion Battery Fuel Gauge
    • Resides on System Board
    • Supports Embedded or Removable Batteries
    • Powered Directly from Battery with Integrated LDO
  • Easy To Configure Fuel Gauging Based on the Dynamic Voltage Correlation Algorithm
    • Reports Remaining Capacity and State of Charge (SOC) with Smoothing Filter
    • Automatically Adjusts for Self-Discharge, Temperature, and Rate Changes
  • Microcontroller Peripheral Supports:
    • 400-kHz I2C Serial Interface
    • Configurable SOC Interrupt or
      Battery Low Digital Output Warning
    • Internal Temperature Sensor or
      Host Reported Temperature
  • Support 4.2-V, 4.3-V, and 4.35-V Chemistries
  • 9-pin 1.62 × 1.58 mm, 0.5 mm pitch YZF package

2 Applications

  • Smartphones, Feature Phones, and Tablets
  • Digital Still and Video Cameras
  • Handheld Terminals
  • MP3 or Multimedia Players

3 Description

The Texas Instruments bq27621-G1 is a minimally configured microcontroller peripheral that provides system-side fuel gauging for single-cell Li-Ion batteries. The device requires very little user configuration and system microcontroller firmware development.

The bq27621-G1 uses the Dynamic Voltage Correlation algorithm for fuel gauging. This process eliminates the need for a sense resistor when calculating remaining battery capacity (mAh), state-of-charge (%), battery voltage (mV), and temperature (°C).

Battery fuel gauging with the bq27621-G1 requires connections only to PACK+ (P+) and PACK– (P–) for a removable battery pack or embedded battery circuit. The tiny 9-pin, 1.62 mm × 1.58 mm, 0.5 mm pitch YZF package is ideal for space-constrained applications.

Device Information(1)

BQ27621-G1YZF (9)1.62 mm × 1.58 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

bq27621-G1 typ_app_bq27621.gif