Triple-input relaxation oscillator with differential controllability

A relaxation oscillator, comprising:

• first and second load transistors, each having a gate configured to receive a reference voltage, a source configured to receive a supply voltage, and a drain;
• first and second switching transistors, each having a respective drain connected in signal communication with the drain of the first and second load transistors, respectively, a respective gate connected in signal communication with the drain of the second and first load transistors, respectively, and a source;
• a fine-tuning varactor, having first and second ends connected in signal communication with the respective source of the first and second switching transistors, respectively, configured to provide fine-tuning of an oscillator output;
• and
• first and second current sources, each having a first terminal configured to receive a ground voltage, and a second terminal connected in signal communication with the first end and the second end, respectively, of the fine-tuning varactor, configured to provide coarse-tuning of the oscillator output.