SLUSBU9I March   2014  – August 2024 BQ2970 , BQ2971 , BQ2972 , BQ2973

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1. 5.1 Pin Descriptions
      1. 5.1.1 Supply Input: BAT
      2. 5.1.2 Cell Negative Connection: VSS
      3. 5.1.3 Voltage Sense Node: V–
      4. 5.1.4 Discharge FET Gate Drive Output: DOUT
      5. 5.1.5 Charge FET Gate Drive Output: COUT
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 DC Characteristics
    6. 6.6 Programmable Fault Detection Thresholds
    7. 6.7 Programmable Fault Detection Timer Ranges
    8. 6.8 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Timing Charts
    2. 7.2 Test Circuits
    3. 7.3 Test Circuit Diagrams
  9. 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 Normal Operation
      2. 8.4.2 Overcharge Status
      3. 8.4.3 Over-Discharge Status
      4. 8.4.4 Discharge Overcurrent Status (Discharge Overcurrent, Load Short-Circuit)
      5. 8.4.5 Charge Overcurrent Status
      6. 8.4.6 0V Charging Function Enabled
      7. 8.4.7 0V Charging Inhibit Function
      8. 8.4.8 Delay Circuit
  10. 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
      3. 9.2.3 Application Performance Plots
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Related Documentation
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.1 Overview

This BQ2970 device is a primary protector for a single-cell Li-ion/Li-polymer battery pack. The device uses a minimum number of external components to protect for overcurrent conditions due to high discharge/charge currents in the application. In addition, it monitors and helps to protect against battery pack overcharging or depletion of energy in the pack. The BQ2970 device is capable of having an input voltage of 8V from a charging adapter and can tolerate a voltage of BAT – 25V across the two input pins. In the condition when a fault is triggered, there are timer delays before the appropriate action is taken to turn OFF either the CHG or DSG FETs. The recovery period also has a timer delay once the threshold for recovery condition is satisfied. These parameters are fixed once they are programmed. There is also a feature called zero voltage charging that enables depleted cells to be charged to an acceptable level before the battery pack can be used for normal operation. Zero voltage charging is allowed if the charger voltage is above 1.7V. For Factory Programmable Options, see Table 8-1.

Table 8-1 Factory Programmable Options
PARAMETERFACTORY DEVICE CONFIGURATION
VOVPOvercharge detection voltage3.85V to 4.60V in 50mV steps
VUVPOver-discharge detection voltage2.00V to 2.80V in 50mV steps
VOCDDischarging overcurrent detection voltage90mV to 200mV in 5mV steps
VOCCCharging overcurrent detection voltage–45mV to –155mV in 5mV steps
VSCCShort Circuit detection voltage300mV, 400mV, 500mV, 600mV
tOVPDOvercharge detection delay time0.25s, 1.00s, 1.25s, 4.50s
tUVPDOver-discharge detection delay time20ms, 96ms, 125ms, 144ms
tOCDDDischarging overcurrent detection delay time8ms, 16ms, 20ms, 48ms
tOCCDCharging overcurrent detection delay time4ms, 6ms, 8ms, 16ms
tSCCDShort Circuit detection delay time250µs (fixed)

For available released devices, see the Released Device Configurations table.