Patent ID: 7659788

Claim:
An amplitude regulating circuit for an oscillator with an input for a supply signal comprising an electrical quantity depending on an amplitude of an oscillation of the oscillator, the amplitude regulating circuit comprising: a supply circuit with a control input for a first control signal and a supply output for the supply signal based on the first control signal; a reference circuit with an input for a reference supply signal comprising a reference quantity; a reference supply circuit with a reference control input for a second control signal and a reference supply output for the reference supply signal based on the second control signal; and a comparator circuit with a first input coupled to the supply output, a second input coupled to the reference supply output, a first control signal output for the first control signal based on the electrical quantity and the electrical reference quantity, coupled to the control input, and a second control signal output for the second control signal based on the electrical quantity and the electrical reference quantity, coupled to the reference control signal input.