An oscillator circuit for a plurality of resonator-based oscillators is provided. In a dual oscillator circuit, a first oscillator circuit operating at a first frequency is coupled to a second oscillator circuit operating at a lower frequency. The two circuits are separated by a low-pass filter that isolates the input stage of the first oscillator circuit from the input stage of the second oscillator circuit. A circuit leg shared between the first oscillator circuit and the second oscillator circuit is configured to couple the first input stage of the first oscillator circuit to a first external resonator resonate at the first frequency and couple the second input stage of the second oscillator circuit to a second external resonator resonate at the second frequency.