A 1.02nW PMOS-Only, Trim-Free Current Reference with 282ppm/°C from -40°C to 120°C and 1.6% within-Wafer Inaccuracy


A 1.02nW current reference is designed with only PMOS transistors, thereby providing inherently low process variation and enabling trim-free operation. Thirty-two measured chips from 5 corner wafers in 180nm CMOS technology show an untrimmed within-wafer spread ($σ$/$μ$) of 1.6% and across-corner wafer-to-wafer spread of $±$4.7%. The measured average temperature coefficient is 282ppm/°C from -40°C to 120°C while generating a 35nA reference current. Total untrimmed uncertainty due to variations of process, voltage, and temperature is about 8.8%.

ESSCIRC 2017 - 43rd IEEE European Solid State Circuits Conference
Kaiyuan Yang
Assistant Professor of ECE