A 250-MHz monolithic voltage-controlled oscillator with low temperature coefficient

A monolithic voltage-controlled oscillator (VCO) with dual-loop feedback, designed and fabricated in a 2- mu m oxide-isolated bipolar technology, is discussed. The VCO, consuming 220 mW from a single 5-V supply and occupying 2200 mil/sup 2/, achieves a -65 p.p.m./ degrees C temperature coefficient of frequency. It has a 5:1 frequency control range, and the maximum oscillation frequency is 250 MHz with better than a 2% voltage-to-frequency linearity. The modulation bandwidth of the VCO is greater than 12 MHz, and the power supply rejection ratio is 0.4%/V.<
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