In this paper, we designed a thermal shutdown block for LED applications using a 1 μm CMOS process. The proposed thermal shutdown protection circuit has been designed with a shut-off temperature of 120 °C and a restart temperature of 90 °C which are suitable conditions for LED driver IC. Also, we got SPICE simulation results of the circuit about process variation of the semiconductor fabrication. From simulation data, process variation rate of the proposed circuit are within 7 % which are good results compared with conventional BJT current mirror type circuit. Finally, we confirmed that the thermal shutdown circuit has good thermal protection function within a LED driver IC.