Resistorless self-biased curvature compensated sub-1V CMOS bandgap reference

A Bandgap Voltage Reference (BGR) circuit technique for lower voltage supply operation is presented. It eliminates the need of BGR core and resistors by integrating a two-stage cascode operational amplifier (op-amp) biased with a start-up circuitry with all-MOSFET transistors. The circuit is designed in 0.13μm CMOS process technology, produced a 179mV reference voltage at 27°C with 0.4V supply voltage. The simulated voltage reference achieved 0.02ppm/°C temperature coefficient over −60°C to 45°C temperature range as well as ±170mV over supply voltage variation from 0.1V to 1.2V. The design is simulated and verified with Mentor Graphics.