A typical bandgap voltage reference based on CSMC 0.35 μm CMOS technology is designed and fabricated. The overall bandgap architecture is optimized to achieve high accuracy temperature and power supply independent voltage reference. The design consists of the bandgap core circuit, op-amp, and start-up circuit. The test results show that the bandgap reference circuit provides reference voltage of 1.2128 V to 1.2175 V with 3.3 V power supply and temperature range from -40°C to 80°C simultaneously, and the temperature coefficient is 32.2ppm/°C. The total layout area including dummy structures is 135 um×236 um.