TIDUF44 January   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 BQ76907
      2. 2.2.2 BQ76905
      3. 2.2.3 BQ77207
      4. 2.2.4 MSPM0L1106
      5. 2.2.5 TCAN1042
      6. 2.2.6 TPSM365R6V5
      7. 2.2.7 TLV704
      8. 2.2.8 TMP61
  9. 3System Design Theory
    1. 3.1 Primary Protection Design
    2. 3.2 Secondary Protection
    3. 3.3 Other Circuit Design
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
    4. 4.4 Test Results
      1. 4.4.1 Cell Voltage Accuracy
      2. 4.4.2 Pack Current Accuracy
      3. 4.4.3 Protection
      4. 4.4.4 Cell Balancing
      5. 4.4.5 Working Modes Transition
      6. 4.4.6 Thermal Performance
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

4.4.1 Cell Voltage Accuracy

When testing cell voltage accuracy, do not use a resister divider to simulate battery cells. Since there is some current flowing into cell input pins when doing ADC measurement, the resister divider causes further voltage drop and makes the AFE readings lower than the actual value. The design uses a battery simulator for accuracy testing. Table 4-1 shows the cell voltage accuracy data without any further calibrations and under room temperature. All channels of cell voltage error are below ±5 mV.

Table 4-1 Cell Voltage Accuracy Data
MEASURING VOLTAGE (mV)CELL 1 (mV)CELL 2 (mV)CELL 3 (mV)CELL 4 (mV)CELL 5 (mV)CELL 6 (mV)CELL 7 (mV)CELL ERROR 1 (mV)CELL ERROR 2 (mV)CELL ERROR 3 (mV)CELL ERROR 4 (mV)CELL ERROR 5 (mV)CELL ERROR 6 (mV)CELL ERROR 7 (mV)
2000200020001999200020002000200000–10000
2250225022502249225022492250225000–10–100
2500250025002499250025002499250000–10010
2750275027502749275027492750275000–10–100
300030002999299930002999300030000–1–10–100
325032503248324932503249325032500–2–10–100
35003499349834993500349934993500–1–2–10–110
37503749374837493750374937503750–1–2–10–100
40003999399839994000399939994000–1–2–10–110
42504249424842494250424942494250–1–2–10–110