10MHz RC Frequency Reference with a 1-Point On-Chip-Trimmed Inaccuracy of $\boldsymbol{\pm 0.28\%}$ from $\boldsymbol{-45^{\mathrm{o}}\mathrm{C}}$ to $\boldsymbol{125^{\mathrm{o}}\mathrm{C}}$ in 0.18μm CMOS.