Patent ID: 8116049

Claim:
A transient voltage detection circuit, suitable for an electronic system, the electronic system comprising a high voltage line and a low voltage line, the transient voltage detection circuit comprising: at least one detection circuit, wherein each detection circuit comprises: a P-type metal-oxide-semiconductor field-effect transistor (PMOS), the PMOS comprising a source electrode, a drain electrode and a bulk electrode, the source electrode being coupled with the bulk electrode, the source electrode also being coupled to the high voltage line, a parasitic diode being formed between the drain electrode and the bulk electrode of the PMOS; a capacitor coupled between the low voltage line and the drain electrode; and a detection node coupled between the drain electrode and the capacitor, when a transient voltage occurs on the high voltage line, the PMOS being in an off-state, the capacitor discharging through the parasitic diode to the high voltage line, such that a voltage level of the detection node is lowered; and a judge module coupled to the detection node of each detection circuit respectively, the judge module judging the voltage level of each detection node and generating a judgment, the electronic system selectively performing a protective action according to the judgment.