SLVU957A September   2019  – November 2021 BQ76922

 

  1.   Trademarks
  2. 1Features
    1. 1.1 Kit Contents
    2. 1.2 Ordering Information
    3. 1.3 BQ76922EVM Circuit Module Performance Specification Summary
    4. 1.4 Required Equipment
  3. 2BQ76922EVM Quick Start Guide
    1. 2.1 Before You Begin
    2. 2.2 Quick Start
  4. 3Interface Adapter
  5. 4Battery Management Studio Software
    1. 4.1 System Requirements
    2. 4.2 Installing BQStudio
    3. 4.3 BQ76922 bqz File Installation
    4. 4.4 BQStudio Operation and Registers View
    5. 4.5 Commands
    6. 4.6 Data Memory
      1. 4.6.1 Entering, Saving, and Loading Configuration
      2. 4.6.2 OTP Programming
    7. 4.7 Calibration
    8. 4.8 Command Sequences
  6. 5BQ76922EVM Circuit Module Use
    1. 5.1 Cell Simulator
    2. 5.2 Evaluating with Load Current
    3. 5.3 Evaluating Charge and Discharge Currents
    4. 5.4 Evaluating with Simulated Current
    5. 5.5 Reducing the Cell Count
    6. 5.6 Connecting Cells
    7. 5.7 Connecting to a Host
    8. 5.8 Hardware Configuration
      1. 5.8.1 Configuration Jumpers
      2. 5.8.2 Unused Components
    9. 5.9 Configuration Register Programming
  7. 6BQ76922EVM Circuit Module Physical Construction
    1. 6.1 Board Layout
    2. 6.2 Bill of Materials
    3. 6.3 REACH Compliance
    4. 6.4 Schematic
  8. 7Related Documents from Texas Instruments
  9. 8Revision History

5.7 Connecting to a Host

After initial operation of the monitor with the BQStudio software, it may be desirable to operate the board connected to and controlled by a microcontroller board. J5 could be used to connect I2C signals to the microcontroller board with GND and REG1 for a power supply from J2. The user should note that the J2 GND is connected to the BQ76922 VSS and BAT- while the J5 reference is PACK-. With the connection shown in Figure 5-6 the MCU runs from the battery voltage inside the protection FETs. The shunts on J7 must be positioned to connect the BQ76922 I2C lines to the external connector. If the MCU board provides pull ups for the I2C lines, remove any PU shunts from J7. If 10kohm pull ups are desired to REG1 for the SCL and SDA install shunts on the PU pins of J7. The microcontroller board GND could alternately be referenced to the PACK- at J5. In this case the REG1 power supply would be modulated by the battery current. Since the sense resistor is small, this is not normally a concern, but the user should be aware of the difference. Do not connect the same GND reference to both the J2 GND and the J5 PACK- since this shorts the sense resistor through the external equipment and may lead to damage or unexpected results.

CAUTION:

Do not connect the MCU board to both the J2 GND and J5 PACK- terminals, this shorts the sense resistor and could result in damage to equipment or unexpected results.

Figure 5-6 Host Connection Concept