The linear constant current regulator is a simple, economical and robust device designed to provide a cost effective solution for regulating current in LEDs (similar to Constant Current Diode, CCD). The constant current regulator is based on Self-Biased Transistor (SBT) technology and regulates current over a wide voltage range. It is designed with a negative temperature coefficient to protect LEDs from thermal runaway at extreme voltages and currents. The constant current regulator turns on immediately and is at 25% of regulation with only 0.5 V Vak. It requires no external components allowing it to be designed as a high or low side regulator. The high anode-cathode voltage rating withstands surges common in Automotive, Industrial and Commercial Signage applications. The constant current regulator comes in thermally robust packages and is qualified to AEC-Q101 standard, and UL94-V0 certified.