Non-inverting multi-mode oscillator

An oscillator circuit, comprising:

• a non-inverting sustaining amplifier, the non-inverting sustaining amplifier comprises an amplifier input and an amplifier output;
• and
• a feedback network, the feedback network comprises:
• a crystal, the crystal of the feedback network connected between the amplifier input and the amplifier output of the non-inverting sustaining amplifier;
• an input portion, the input portion connected between the amplifier input and ground, the input portion comprises an inductor, a tank circuit capacitor, and a tank circuit resistor, wherein the inductor forms a first path between the amplifier input and ground, and wherein the tank circuit capacitor and the tank circuit resistor are connected in series and form a second path between the amplifier input and ground, the second path being separate from but parallel to the first path;
• and
• an output portion, the output portion connected between the amplifier output and ground, the output portion comprises a capacitor.