SLUSCE2D April   2016  – January 2019

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Timing Requirements
    7. 7.7 Typical Operational Characteristics (Protection Circuits Waveforms)
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Power-Down or Undervoltage Lockout (UVLO)
      2. 8.3.2 Power-up
      3. 8.3.3 Sleep Mode
      4. 8.3.4 New Charge Cycle
      5. 8.3.5 Overvoltage-Protection (OVP) – Continuously Monitored
      6. 8.3.6 CHG Terminal Indication
    4. 8.4 Device Functional Modes
      1. 8.4.1  CHG LED Pull-up Source
      2. 8.4.2  IN-DPM (VIN-DPM or IN-DPM)
      3. 8.4.3  OUT
      4. 8.4.4  ISET
      5. 8.4.5  TS
      6. 8.4.6  Termination and Timer Disable Mode (TTDM) - TS Terminal High
      7. 8.4.7  Timers
      8. 8.4.8  Termination
      9. 8.4.9  Battery Detect Routine
      10. 8.4.10 Refresh Threshold
      11. 8.4.11 Starting a Charge on a Full Battery
  9. 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
        1. 9.2.2.1 Calculations
          1. 9.2.2.1.1 Program the Fast Charge Current, ISET:
          2. 9.2.2.1.2 Pre-Charge and Termination Current Thresholds, ITERM, and PRE-CHG
          3. 9.2.2.1.3 TS Function
          4. 9.2.2.1.4 CHG
        2. 9.2.2.2 Selecting In and Out Terminal Capacitors
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
      1. 11.3.1 Leakage Current Effects on Battery Capacity
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    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

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

8.3.6 CHG Terminal Indication

The charge terminal has an internal open drain FET which is on (pulls down to VSS) during the first charge only (independent of TTDM) and is turned off once the battery reaches voltage regulation and the charge current tapers to the termination threshold set by the PRE-TERM resistor. The bq21040 does not terminate charge, however, the CHG terminal will turn off once the battery current reaches 10% of the programmed charge current.

The charge terminal is high impedance in sleep mode and OVP and returns to its previous state once the condition is removed.

Cycling input power, pulling the TS terminal low and releasing or entering pre-charge mode causes the CHG terminal to go reset (go low if power is good and a discharged battery is attached) and is considered the start of a first charge.