An overvoltage protected semiconductor switch.

摘要

An overvoltage protected switch (1) includes a power semiconductor device (10) formed by a plurality of second regions (11) within a first region (3) of a semiconductor body (2), and an insulated gate 12 overlying a conduction channel region (13) between each second region (11) and the first region (3) with the first and second regions (3 and 11) providing a conductive path to first and second main electrodes (4 and 5), respectively, of the switch (1). An auxiliary semiconductor device (100) is formed by a number of further second regions (11), less than the plurality of second regions (11), and a further insulated gate (120) overlying a further conduction channel region (13) between each further second region (11) and the first region (3). A further conductive path connects the further second region (11) to the insulated gate (12) of the power semiconductor device (10) and a diode arrangement (30) connects the insulated gate (120) of the auxiliary semiconductor device (100) to the first main electrode (4) for causing the auxiliary semiconductor device (100) to conduct to supply a signal via the further inductive path to the insulated gate (12) of the power semiconductor device (10) to switch the power semiconductor device (10) on when the voltage on the first main electrode (4) exceeds the predetermined value. The auxiliary semiconductor device (100) thus has a large current-handling capability enabling rapid turn-on of the power device (10) in the event of an overvoltage.