188.8.131.52 Distinguishing of Different Fault Modes
Some applications require that open load, short to battery, and short to GND can be distinguished from each other. This requires two steps:
- In the on-state, for the current-sense version device (version B), on-state open load and short to battery are recognized as an extremely-low voltage level on the current-sense pin, whereas short to GND is reported as a pulled-up voltage VCS,h. Therefore, the user can find a short to GND (see Figure 46).
- If reported as an on-state open-load or short-to-battery fault in the first step, turn off the input signal. In the off-state, with an external pulldown resistor, open load and short to battery can be easily distinguished. When the output pulls down, the short to battery is still reported as an off-state fault condition, whereas the open load is ignored.
Figure 46. Step 1: Short-to-GND Detection in the On-State
Figure 47. Step 2: Short-to-Battery Detection in the Off-State