1.2 MHz relaxation oscillator with 16.8 ppm/°C temperature coefficient using resistive self‐bias current

Abstract

In this research, the authors propose a self‐biased relaxation oscillator that outputs a constant 1.2 MHz clock over a wide temperature range. Excluding any external bias, the proposed oscillator embodies a self‐bias circuit that generates a bias current from a precisely trimmed resistor. To minimise the power consumption, a switched‐bias technique was applied to the two comparators in the oscillator. The proposed circuit was fabricated in a 180 nm CMOS process. It consumes 17.9 µW from a 1.5 V supply, and its temperature coefficient is 16.8 ppm/°C in the range of −20–80°C.

Keywords

• self‐biased relaxation oscillator
• wide temperature range
• external bias
• self‐bias circuit
• bias current
• precisely trimmed resistor