SDAA369 August   2026 BQ76952 , BQ78706

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2CELL Open-Wire Detection Flow
    1. 2.1 VC1-VCn-1 Open-Wire Detection
    2. 2.2 VCn Open-Wire Detection
    3. 2.3 VC0 Open-Wire Detection
  6. 3Shunt Open-Wire Detection
    1. 3.1 Open-Wire Detection Solution of Shunt
    2. 3.2 Current-Sense Diagnostics with Redundant ADC
  7. 4Other Diagnostics: VBAT, VSS
    1. 4.1 VBAT Open-Wire Detection
    2. 4.2 VSS Open-Wire Detection
  8. 5Summary
  9. 6References

2.2 VCn Open-Wire Detection

Discharge Path During VC16 Open-Wire DetectionFigure 2-2 Discharge Path During VC16 Open-Wire Detection

When the CELL16 input pin is floating due to an open-wire condition, the internal current source discharges CVC_16 with a slew rate. The voltage on CVC_16 continues to decrease until the body diode of the internal CELL-balancing FET becomes forward biased. Eventually, the voltage difference between VC16~VC15 is close to 0 V. The BQ device can report a CUV event for CELL 16. In this condition, VSTACK becomes equal to the sum of 15 CELL voltages, while VBAT remains equal to the sum of all 16 CELL voltages.