A Low-Noise Sub-Bandgap Reference with a ±0.64% Untrimmed Precision in 16nm FinFET

This paper presents a new concept for sub- bandgap circuits, based on direct generation of PTAT current with larger and adjustable temperature coefficient. The reference voltage is generated inside the feedback loop, which facilitates good supply rejection, low-noise and high precision performance. A 3σ - spread of only ± 0.64 % across split-lots was observed in a 16 nm FinFET process on 4400 μm², without trimming or any switching techniques. By using NPN bipolar devices, noise levels of ~130nV/sqrt(Hz) at 1 kHz can be achieved at 125 μA power drain. Different configurations are explained, which allow flexible reference levels or very low supply voltages of <; 0.85 V.