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

8.4.3 Over-Discharge Status

If the battery voltage drops below the over-discharge detection voltage (VUVP) for a time greater than (tUVPD) the discharge control output, DOUT is switched to a low state and the discharge FET is turned OFF to prevent further discharging of the battery. This is referred to as an over-discharge detection status. In this condition, the V– pin is internally pulled up to BAT by the resistor RV–D. When this occurs, the voltage difference between V– and BAT pins is 1.3V or lower, and the current consumption of the device is reduced to power-down level ISTANDBY. The current sink IV–S is not active in power-down state or over-discharge state. The power-down state is released when a charger is connected and the voltage delta between V– and BAT pins is greater than 1.3V.

If a charger is connected to a battery in over-discharge state and the voltage detected at the V– is lower than –0.7V, the device releases the over-discharge state and allows the DOUT pin to go high and turn ON the discharge FET once the battery voltage exceeds over-discharge detection voltage (VUVP).

If a charger is connected to a battery in over-discharge state and the voltage detected at the V– is higher than –0.7V, the device releases the over-discharge state and allows the DOUT pin to go high and turn ON the discharge FET once the battery voltage exceeds over-discharge detection release hysteresis voltage (VUVP +Hys).