Oscillator circuits, electronic devices, and methods are disclosed. In one embodiment, an oscillator circuit includes a plurality of oscillator transistors comprising a plurality of gates, a plurality of adjustment transistors coupled to the plurality of gates, a differential output coupled to the plurality of oscillator transistors, a plurality of current transistors configured to receive one or more mixed bias current outputs, and generate a main current based on the one or more mixed bias current outputs, the one or more mixed bias current outputs and the main current being substantially constant over a range of temperatures, and one or more switches configured to set an oscillation frequency of the differential output by driving a first portion of a main current through at least one of the plurality of oscillator transistors, and driving a second portion of the main current through at least one of the plurality of adjustment transistors.