Patent ID: 6633473
Filing Date: 2003-10-14
Classification: H01L,H03K

Abstract:
An overcurrent limiting circuit of a power semiconductor element which has first and second regions for passing a main current, a third region for controlling said main current which flows from said first region towards said second region, a current detecting region for passing a current sense current from said second region, and a first electrode terminal, a second electrode terminal, a third electrode terminal, and a current sense terminal connected to said first region, said second region, said third region, and said current detecting region, respectively, comprising:a resistor connected between said second electrode terminal and said current sense terminal; a transistor comprising a first main electrode, a second main electrode, and a main control electrode connected to said third electrode terminal, said second electrode terminal, and said current sense terminal, respectively, which comes into an ON state to pass a current from said first main electrode towards said second main electrode when a voltage not lower than a first control voltage is applied to said main control electrode; and a voltage clamping circuit connected between said main control electrode and said second main electrode of said transistor, for clamping a voltage applied to said main control electrode to a second control voltage not lower than said first control voltage when a voltage which is a product of said current sense current and a value of said resistor becomes a predetermined value not lower than said first control voltage.