SLUSCI1B August   2016  – November 2016

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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  Electrical Characteristics: Supply Current
    6. 6.6  Electrical Characteristics: Digital Input and Output DC Characteristics
    7. 6.7  Electrical Characteristics: Power-On Reset
    8. 6.8  Electrical Characteristics: LDO Regulator
    9. 6.9  Electrical Characteristics: Internal Temperature Sensor
    10. 6.10 Electrical Characteristics: Low-Frequency Clock Oscillator
    11. 6.11 Electrical Characteristics: High-Frequency Clock Oscillator
    12. 6.12 Electrical Characteristics: Integrating ADC (Coulomb Counter)
    13. 6.13 Electrical Characteristics: ADC (Temperature and Voltage Measurements)
    14. 6.14 Electrical Characteristics: Data Flash Memory
    15. 6.15 Timing Requirements: I2C-Compatible Interface Timing Characteristics
    16. 6.16 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Communications
        1. 7.3.1.1 I2C Interface
        2. 7.3.1.2 I2C Time Out
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 BAT Voltage Sense Input
        2. 8.2.2.2 SRP and SRN Current Sense Inputs
        3. 8.2.2.3 Sense Resistor Selection
        4. 8.2.2.4 TS Temperature Sense Input
        5. 8.2.2.5 Thermistor Selection
        6. 8.2.2.6 REGIN Power Supply Input Filtering
        7. 8.2.2.7 REG25 LDO Output Filtering
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Power Supply Decoupling Capacitor
      2. 10.1.2 Capacitors
      3. 10.1.3 Communication Line Protection Components
    2. 10.2 Layout Example
      1. 10.2.1 Ground System
      2. 10.2.2 Kelvin Connections
      3. 10.2.3 Board Offset Considerations
      4. 10.2.4 ESD Spark Gap
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9 Power Supply Recommendations

Power supply requirements for the bq34110 device are simplified due to the presence of the internal LDO-voltage regulation. The REGIN pin accepts any voltage level between 2.7 V and 4.5 V, which is optimum for a single-cell Li-Ion application. For higher battery voltage applications, a simple preregulator can be provided to power the bq34110 device. Decoupling the REGIN pin should be done with a 0.1-μF 10% ceramic X5R capacitor placed close to the device. While the preregulator circuit is not critical, special attention should be paid to its quiescent current and power dissipation. The input voltage should handle the maximum battery stack voltage. The output voltage can be centered within the 2.7-V to 4.5-V range as recommended for the REGIN pin.

For high stack count applications, a commercially available LDO is often the best quality solution, but comes with a cost tradeoff. To lower the BOM cost, the following approaches are recommended.

In Figure 17, Q1 is used to drop the battery stack voltage to roughly 4 V to power the bq34110 device's REGIN pin. To avoid unwanted quiescent current consumption, R1 should be set as high as is practical. It is recommended to use a low-current Zener diode.

bq34110 Q1DropBatVoltage.gif Figure 17. Q1 Dropping Battery Stack Voltage to 4 V

Alternatively, if the range of a high-voltage battery stack can be well-defined, a simple source follower based on a resistive divider can be used to lower the BOM cost and the quiescent current. For example:

bq34110 Q1SourceFollower.gif Figure 18. Source Follower on a Resistive Divider