31.3 A 0.14mm2 16MHz CMOS RC Frequency Reference with a 1-Point Trimmed Inaccuracy of ±400ppm from -45°C to 85°C

Recently, rapid strides have been made in improving the accuracy of RC-based frequency references [1 –3]. Inaccuracies better than $\pm 500ppm$ from $-45^{\circ}C$ to $85^{\circ}C$ have been achieved, but typically at the expense of a costly and time-consuming 2-point trim to compensate for RC spread and temperature dependence. This paper describes a 16MHz RC-based frequency reference that achieves $\pm 400ppm$ inaccuracy over the industrial temperature range with a single room-temperature (RT) trim. The prototype draws $88\mu$A from a1.8V supply and occupies $0.14mm^{2}$, which represents a $2\times$ improvement in both power and area compared to the state of the art [2].