Patent ID: 8526149

Claim:
A limiting current circuit that has output short circuit protection being connected to an external voltage source and comprising an output terminal being connected to a load and has an output current; an input current unit controlling voltage across the input current unit to maintain a constant current and having an input being connected to the external voltage source; and an output; a driving transistor having an internal resistance, a drain current and a gate voltage and comprising a gate being connected to the output of the input current unit; a drain being connected to the external voltage source; and a source; a voltage control resistor having a resistor voltage and comprising a first end being connected to the source of the driving transistor; and a second end being connected to the output terminal; a voltage control transistor comprising a gate; a drain being connected to the output of the input current unit; and a source being connected to the second end of the voltage control resistor and the output terminal; and having an internal resistance; and a parasitic capacitance between the gate and the source of the voltage control transistor; and a delay unit making the resistor voltage charging the parasitic capacitance extend the period of lower internal resistance of the voltage control transistor and the period of higher internal resistance of the driving transistor, making the internal resistance of the voltage control transistor less than the internal resistance of the driving transistor when the load being shorted and comprising a first end being connected to the gate of the voltage control transistor; and a second end being connected to the source of the driving transistor.