A self-biased op-amp-free bandgap voltage reference circuit was designed in a 0.35 μm BCD technology to address the issues of input offset affecting voltage accuracy and poor power supply rejection in traditional references. It stabilized the output reference voltage through a negative feedback network, effectively eliminating the influence of the operational amplifier’s input offset voltage. By combining negative feedback and common-source/common-gate current mirrors, it enhances the reference’s immunity to interference, ensuring improved power supply rejection. The circuit utilized exponential curvature compensation for excellent temperature characteristics over a wide voltage range. Additionally, the self-biasing scheme minimized static current consumption. Simulation results demonstrate a 1.271 V output reference voltage at a 5 V supply, with a temperature coefficient of 5.46 ×10-6/℃ from -40 to 150 ℃, a -87 dB power supply rejection at DC, and a static current consumption of 2.3 μA. It is suitable for low power PM chips.