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

5.6 Connecting Cells

The EVM is constructed with a single connection to the top and bottom of the cell stack. Cell voltage for these cells is sensed on the board.

While the EVM has a place to mount an activated fuse, the pattern is shorted to allow easy evaluation without the concern of activating the fuse. When connecting cells use a fuse in the current path and any other signal path appropriate for your application.

The cell simulator provides resistors between the cell inputs. When the cell simulator shunts are installed, these resistors load the cells, and divide the voltage to any unconnected inputs as cells are connected. If desired, the cell simulator shunts can be installed during cell connection and removed after cell connection. The shunts must be removed after connection of cells, or the cells are discharged by the constant drain of the cell simulator resistors.

BAT- is the reference voltage for the IC and should be connected first. After BAT- cells may be connected in any order. Cell connection from the bottom up minimizes the voltage step size applied to the board. Recommended connection sequence for the EVM when connecting cells is bottom up:

  1. Connect BAT–
  2. Connect cells bottom up; CELL1, CELL2, CELL3 ...
  3. Be sure the cell simulator shunts are removed

Figure 5-5 shows an example connecting cells with an EVM configuration reduced to 4 cells. Be sure the Vcell mode is configured for the cells used. In this example 0x0017.

Figure 5-5 Example Connection with 4 Cells