1. A current reference generator comprising: a first voltage reference configured to generate a first current through a first resistor; a second voltage reference configured to generate a second current; a first current mirror configured to subtract the second current from the first current to generate a temperature invariant current; a third voltage reference configured to generate a third current; and a second current mirror configured to: subtract the temperature invariant current from the third current to produce a process-temperature invariant current, and output the process-temperature invariant current.