A programmable clock oscillator for integrated sensor applications

This paper presents a programmable two-phase non-overlapping clock oscillator used for integrated sensors with wide operating temperature, low-cost and robust requirements. It is based on a proposed gain-enhanced VI converter to drive two one-shot timers arranged in a ring configuration together with the start-up circuit. Experimental results verify that the clock oscillation frequency varies less than 0.5% from temperature -40°C to +125°C in an integrated sensor interface for air-bag accelerometer. For a +/-10% variation in supply, the frequency shifts +0.45/-0.83%. The measured frequencies of the sample ICs have a mean of 1.6% in deviation from the simulated 256 kHz and a standard derivation of 1.37%. The oscillator circuit occupies 0.26 mm² using 0.8 ¿m CMOS technology.