Patent ID: 7881031

Claim:
A system comprising a packaged integrated circuit, the integrated circuit incorporating a current setting circuit, the package having an external first terminal for connecting a current selection device thereto for setting a current generated by the current setting circuit, the current setting circuit comprising: a first transistor for conducting a first current in response to a control signal; a first controller having an input terminal for receiving a signal related to the first current (Iset) through the first transistor and having a control signal output terminal coupled to control the first transistor, the first controller setting the first current through the first transistor based on a characteristic of the current selection device externally connected to the first terminal of the package; a first current mirror generating a second current (A 1 *Iset) related to the first current, wherein the first current mirror comprises a first current mirror transistor in series with the first transistor, where the first current (Iset) through the first current mirror transistor determines the second current (A 1 *Iset); a current sensor for sensing the second current; and a current limiting transistor connected to the current sensor, the current limiting transistor conducting current when the current sensor senses the second current exceeding a threshold due to the characteristic of the current selection device externally connected to the first terminal of the package, the current limiting transistor being connected to the first transistor to limit the first current through the first transistor when the current sensor senses that the second current has exceeded the threshold.