J511 Current Regulator Diode Linear Systems replaces discontinued Siliconix J511 The Linear Systems J511 is a ± 20% range current regulator The J511 is a ±20% range current regulator designed for demanding applications in test equipment and instrumentation. The J511 utilizes JFET techniques to produce a single two-leaded device which is extremely simple to operate. Two-Lead Plastic Package Guaranteed ±20% Tolerance .