SLUSCB7A March   2016  – April 2016

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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  Supply Current
    6. 6.6  Digital Input and Output DC Characteristics
    7. 6.7  LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics
    8. 6.8  LDO Regulator, Wake-up, and Auto-shutdown AC Characteristics
    9. 6.9  ADC (Temperature and Cell Measurement) Characteristics
    10. 6.10 Integrating ADC (Coulomb Counter) Characteristics
    11. 6.11 I2C-Compatible Interface Communication Timing Characteristics
    12. 6.12 SHUTDOWN and WAKE-UP Timing
    13. 6.13 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram (System-Side Configuration)
    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
        3. 7.3.1.3 I2C Command Waiting Time
        4. 7.3.1.4 I2C Clock Stretching
    4. 7.4 Device Functional Modes
  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 Integrated LDO Capacitor
        3. 8.2.2.3 Sense Resistor Selection
      3. 8.2.3 External Thermistor Support
      4. 8.2.4 Application Curves
  9. Power Supply Recommendation
    1. 9.1 Power Supply Decoupling
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

10 Layout

10.1 Layout Guidelines

  • A capacitor of value of at least 2.2 µF is connected between the VDD pin and VSS. The capacitor must be placed close to the gauge IC and have short traces to both the VDD pin and VSS. This regulator must not be used to provide power for other devices in the system.
  • It is required to have a capacitor of at least 1.0 µF connect between the BAT pin and VSS if the connection between the battery pack and the gauge BAT pin has the potential to pick up noise. The capacitor should be placed close to the gauge IC and have short traces to both the BAT pin and VSS.
  • If the external pullup resistors on the SCL and SDA lines will be disconnected from the host during low-power operation, it is recommended to use external 1-MΩ pulldown resistors to VSS to avoid floating inputs to the I2C engine.
  • The value of the SCL and SDA pullup resistors should take into consideration the pullup voltage and the bus capacitance. Some recommended values, assuming a bus capacitance of 10 pF, can be seen in Table 1.
  • Table 1. Recommended Values for SCL and SDA Pullup Resistors

    VPU 1.8 V 3.3 V
    RPU Range Typical Range Typical
    400 Ω ≤ RPU ≤ 37.6 kΩ 10 kΩ 900 Ω ≤ RPU ≤ 29.2 kΩ 5.1 kΩ
  • If the host is not using the GPOUT functionality, then it is recommended that GPOUT be connected to a GPIO of the host so that in the cases where the device is in SHUTDOWN, toggling GPOUT can wake the gauge from the SHUTDOWN state.
  • If the battery pack thermistor is not connected to the BIN pin, the BIN pin should be pulled down to VSS with a 10-kΩ resistor.
  • The BIN pin should not be shorted directly to VDD or VSS.
  • The actual device ground is pin B2 (VSS).
  • The SRP and SRN pins should be Kelvin connected to the RSENSE terminals. SRP to the battery pack side of RSENSE and SRN to the system side of the RSENSE.
  • Kelvin connect the BAT pin to the battery PACKP terminal.

10.2 Layout Example

bq27220 bq27220_layoutDiagram.gif Figure 14. EVM Board Layout