SLUSBU9H March   2014  – June 2021 BQ2970 , BQ2971 , BQ2972 , BQ2973

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1. 6.1 Pin Descriptions
      1. 6.1.1 Supply Input: BAT
      2. 6.1.2 Cell Negative Connection: VSS
      3. 6.1.3 Voltage Sense Node: V–
      4. 6.1.4 Discharge FET Gate Drive Output: DOUT
      5. 6.1.5 Charge FET Gate Drive Output: COUT
  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 DC Characteristics
    6. 7.6 Programmable Fault Detection Thresholds
    7. 7.7 Programmable Fault Detection Timer Ranges
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Timing Charts
    2. 8.2 Test Circuits
    3. 8.3 Test Circuit Diagrams
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
    4. 9.4 Device Functional Modes
      1. 9.4.1 Normal Operation
      2. 9.4.2 Overcharge Status
      3. 9.4.3 Over-Discharge Status
      4. 9.4.4 Discharge Overcurrent Status (Discharge Overcurrent, Load Short-Circuit)
      5. 9.4.5 Charge Overcurrent Status
      6. 9.4.6 0-V Charging Function Enabled
      7. 9.4.7 0-V Charging Inhibit Function
      8. 9.4.8 Delay Circuit
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Performance Plots
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Related Documentation
    2. 13.2 Support Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.1 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 8 V from a charging adapter and can tolerate a voltage of BAT – 25 V 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 1.7 V. For Factory Programmable Options, see Table 9-1.

Table 9-1 Factory Programmable Options
PARAMETERFACTORY DEVICE CONFIGURATION
VOVPOvercharge detection voltage3.85 V to 4.60 V in 50-mV steps
VUVPOver-discharge detection voltage2.00 V to 2.80 V in 50-mV steps
VOCDDischarging overcurrent detection voltage90 mV to 200 mV in 5-mV steps
VOCCCharging overcurrent detection voltage–45 mV to –155 mV in 5-mV steps
VSCCShort Circuit detection voltage300 mV, 400 mV, 500 mV, 600 mV
tOVPDOvercharge detection delay time0.25 s, 1.00 s, 1.25 s, 4.50 s
tUVPDOver-discharge detection delay time20 ms, 96 ms, 125 ms, 144 ms
tOCDDDischarging overcurrent detection delay time8 ms, 16 ms, 20 ms, 48 ms
tOCCDCharging overcurrent detection delay time4 ms, 6 ms, 8 ms, 16 ms
tSCCDShort Circuit detection delay time250 µs (fixed)

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