Untrimmed 6.2 ppm/°C bulk-isolated curvature-corrected bandgap voltage reference

• The paper proposes a block bulk isolation strategy for triple-well processes.
• The substrate noise sensitivity of the designed BGR output is improved more than 100 dB up to 100 MHz.
• The designed BGR achieves the best untrimmed temperature coefficient with minimum area.
• Its noise performance is equivalent to the best reported [14] while occupying 1/2.5 the area.

This paper presents the design of a low-drift, curvature-corrected bandgap voltage reference (BGR) realized in a 0.35μm 3.3 V triple-well CMOS technology having vertical NPN BJT transistors. The proposed circuit takes advantage of a block bulk isolation strategy improving the substrate noise sensitivity at the BGR output more than 100 dB up to 100 MHz. The simulated circuit achieves a mean temperature coefficient of 6.2 ppm/°C over the temperature range of −40 to 125 °C with 4.1 ppm/°C standard deviation without any trimming. The circuit operates down to 2 V and consumes 31.5μA from a single 3.3 V supply. Its line regulation is less than 0.07% per Volt while its supply voltage changes from 2 V to 3.6 V. The power supply rejection (PSR) of the circuit is −76.5 dB at 100 Hz. The peak-to-peak output noise is 4.66μV integrated within the frequency range of 0.1–10 Hz. The proposed circuit occupies an area of (515μm×320μm) 0.165 mm2.