Q: If we use CTCS to do sense wire open or Cn open detection,should we consider the charging or discharging time due to the current source and the filter cap?And how to calculate the delay time?
A: The cell/sense wire open diagnostics use the 100uA pull down. In this case the Cn capacitor will need to be discharged to a specific threshold defined by the UVTHRSET register. Assuming a 4.8V input and a 0.3V threshold this timing is roughly 1.5ms. Additional margin should be added upon this to ensure robustness. Our diagnostic code uses 4ms.