Precise phase start-up voltage controlled oscillator with accurate duty cycle

摘要

A voltage controlled oscillator includes an inverting amplifier connected to a resonant feedback network and a comparator for comparing the input to the inverting amplifier to a reference voltage which is equal to the threshold voltage of the inverting amplifier. As a result, the oscillator provides a square wave output having a precise one-to-one duty cycle. In addition, circuitry is included for causing the oscillator to start up at a steady state value and predetermined phase.