Presented is a gain-boosted gate-bulk-driven error correction amplifier with reduced offset errors for low-voltage sub-bandgap reference designs. The method can be applied to sub-bandgap circuits with BJT diodes, subthreshold MOSFETs or Schottky barrier diodes. Detailed analysis and circuit implementation are presented. Low voltage operation has been verified over-55 to 125 °C. Simulation and measurement results demonstrate the minimised offset error and improved supply sensitivity, which indicates the effectiveness of the proposed gain boosting mechanism.