SLUSA52C September   2010  – March 2016

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Options
  6. 6 Pin Configuration 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 Electrical Characteristics
    6. 7.6 Recommended Cell Balancing Configurations
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Voltage Protection
      2. 8.1.2 Cell Balancing
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Protection (OUT) Timing
      2. 8.3.2 Cell Voltage > VPROTECT
      3. 8.3.3 Cell Connection Sequence
      4. 8.3.4 Cell Balance Enable Control
      5. 8.3.5 Cell Balance Configuration
      6. 8.3.6 Cell Imbalance Auto-Detection (Via Cell Voltage)
      7. 8.3.7 Customer Test Mode
      8. 8.3.8 Test Conditions
    4. 8.4 Device Functional Modes
      1. 8.4.1 NORMAL Mode
      2. 8.4.2 PROTECTION Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Battery Connection
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
    3. 9.3 System Example
      1. 9.3.1 External Cell Balancing
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DRB|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • 2-Series Cell Secondary Protection
  • Automatic Cell Imbalance Correction with External Enable Control
    • ±30-mV Enable, 0-mV Disable Thresholds Typical
  • External Capacitor-Controlled Delay Timer
  • External Resistor-Controlled Cell Balance Current
  • Low Power Consumption ICC < 3 µA Typical (VCELL(ALL) < VPROTECT)
  • Internal Cell Balancing Handles Current
    up to 15 mA
  • External Cell Balancing Mode Supported
  • High-Accuracy Overvoltage Protection:
    • ±25 mV with TA = 0°C to 60°C
  • Fixed Overvoltage Protection Thresholds:
    4.30 V, 4.35 V
  • Small 8L DRB Package

2 Applications

  • 2nd Level Protection in Li-Ion Battery Packs
    • Netbook Computers
    • Power Tools
    • Portable Equipment and Instrumentation
    • Battery Backup Systems

3 Description

The bq2920x device is a secondary overvoltage protection IC for 2-series cell lithium-ion battery packs that incorporates a high-accuracy precision overvoltage detection circuit and automatic cell imbalance correction.

The voltage of each cell in a 2-series cell battery pack is compared to a factory programmed internal reference voltage. If either cell reaches an overvoltage condition, the OUT pin changes from low to high state.

The bq2920x can perform automatic voltage-based cell imbalance correction. Balancing can start when the cell voltages are different by nominally 30 mV or more and stops when the difference is nominally 0 mV. Cell balancing is enabled and disabled by the CB_EN pin.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
bq29200 VSON (8) 3.00 mm × 3.00 mm
bq29209
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

bq29200 bq29209 cell_conf_lusa52.gif