Patent ID: 7408755

Claim:
A DC voltage power control circuit comprising: input terminals; output terminals; current limiting circuit operable to limit the amount of current delivered from said input terminals to said output terminals to a predetermined value, said operation of said current limiting circuit being temperature dependent; said current limiting circuit comprising: a sensor for sensing when said current delivered to said output terminal reaches a predetermined threshold; a first semiconductor switch operable to control said limiting of said amount of current delivered from said input terminals to said output terminals; a second semiconductor switch coupled to and controlling said current limiting state of said first semiconductor switch, wherein said control is temperature dependent; and wherein said current limiting circuit turns on said second semiconductor switch when said predetermined threshold is reached causing said first semiconductor switch to enter said current limiting state; compensation circuit coupled to one of said output terminals and to said current limiting circuit, said compensation circuit controlling said current limiting circuit in a manner that is temperature dependent, such that said temperature dependence of said current limiting circuit and said compensation circuit substantially cancel each other out; short circuit protection circuit coupled to said first semiconductor switch, said short circuit protection circuit being coupled to and controlling said off state of said first semiconductor switch; said short circuit protection circuit including a timer circuit generating a signal after said first semiconductor switch has been in said current limiting state for a predetermined period of time; said short circuit protection circuit responding to said timer circuit signal by causing said first semiconductor switch to enter said off state; and said short circuit protection circuit comprises: a third semiconductor switch coupled to an RC network, said third semiconductor switch turning on in response to the state of the RC network after a predetermined period of time, said turning on of said third semiconductor switch causing said first semiconductor switch to turn off; and a fourth semiconductor switch, which turns on in response to said turning on of said third semiconductor switch, said turning on of said fourth semiconductor switch causing said first semiconductor switch to latch in an off state.