A 50 MHz, 46 μW, 0.28% Accuracy, 67 ppm/°C Relaxation Oscillator in 40nm CMOS Process for Multichannel Integrated Biomedical Recording System

This paper presents design of a high accuracy relaxation oscillator immune to the operating conditions and process variations. Presented oscillator is a part of multi-channel integrated system for biomedical recordings fabricated in the 40nm CMOS technology. By utilizing precision current reference source the 67 ppm/°C temperature coefficient in the _20°C to 120°C temperature range and low sensitivity to the supply voltage in the range of 1V to 1.2V were achieved. With the use of digitally trimmed capacitors the 0.28 % accuracy over process variations was also achieved. Additionally, to ensure self-sufficiency and reliable operation the oscillator was equipped with a power-on reset circuit.