Two high accuracy CMOS RC oscillators with different trimming approach

Two high-accuracy RC Oscillators with different trimming control are demonstrated in this paper. The two oscillators use voltage trimming and current trimming respectively. The experiment results, obtained from the circuits fabricated in 0.5 μm CMOS process indicate the IC oscillators provide a 160KHz clock signal with a frequency spread of ±10% before the trimming. After centering the oscillator at the target frequency, the circuit has the accuracy of ±1.7% frequency variation for voltage trimming method and ±1.9% frequency variation for current trimming method from -20°C to 80°C. The chip areas are 120 μm * 135 μm for voltage trimming and 115 μm * 110 μm for current trimming. The oscillator with voltage trimming has been successfully used in consumer electronic products.