SLVSFZ1 December 2020 TPS27SA08-Q1
The TPS27SA08-Q1 device contains two voltage clamps which protect the device against system-level voltage transients.
The clamp from VBB to GND is primarily used to protect the controller from positive transients on the supply line. The clamp from VBB to VOUT is primarily used to limit the voltage across the FET when switching off an inductive load. Both clamp levels are set to protect the device during these fault conditions. If the voltage potential from VBB to GND exceeds the VBB clamp level, the clamp will allow current to flow through the device from VBB to GND (Path 2). If the voltage potential from VBB to VOUT exceeds VCLAMP, the power FET will allow current to flow from VBB to VOUT (Path 3).