Relaxation oscillator with propagation delay compensation for improving the linearity and maximum frequency
AssigneeInfineon Technologies AG
InventorXiaowu Gong
Life of this patent
Estimating the term…
Abstract
A tunable oscillator comprises a control supply configured to output a control output operable to tune the tunable oscillator. The tunable oscillator further comprises an oscillator circuit configured to output a signal such that a frequency of the signal increases with increasing control output. A control circuit is configured to control the frequency of the oscillator circuit signal in response to a comparison of the oscillator circuit signal with a reference signal. A propagation delay compensation circuit is configured to vary an amplitude of the reference signal at substantially the same frequency as the oscillator circuit signal to compensate for propagation delay of signals from the control circuit to the oscillator circuit.
Claims19
A tunable oscillator comprising:
- a control supply configured to output a control output operable to tune the tunable oscillator;
- an oscillator circuit configured to output a signal such that a frequency of the signal increases with increasing control output;
- a control circuit configured to control the frequency of the oscillator circuit signal in response to a comparison of the oscillator circuit signal with a reference signal;
- and
- a propagation delay compensation circuit configured to vary an amplitude of the reference signal at substantially the same frequency as the oscillator circuit signal to compensate for propagation delay of signals from the control circuit to the oscillator circuit, wherein the propagation delay compensation circuit is further configured to vary the amplitude of the reference signal by oscillating such that a signal is produced that is in phase with the signal output by the oscillator circuit.
A method for compensating the propagation delay in a tunable oscillator comprising the steps of:
- inputting a control current to an oscillator circuit, the control current being operable to tune the tunable oscillator;
- detecting a signal of the oscillator circuit and comparing the signal to a reference signal from a reference circuit to produce a control signal;
- supplying the control signal to both the oscillator and the reference circuit;
- and
- outputting from the reference circuit the reference signal, the reference signal having substantially the same phase as the signal of the oscillator circuit and decreasing in amplitude as the signal of the oscillator circuit increases.
A tunable oscillator comprising:
- a control supply configured to output a control current operable to tune the tunable oscillator;
- an oscillator circuit configured to output a signal such that a frequency of the signal increases with increasing control current;
- a control circuit configured to control the frequency of the oscillator circuit signal in response to a comparison of the oscillator circuit signal with a reference signal;
- and
- a propagation delay compensation circuit configured to output a variable reference signal such that the reference signal has substantially the same phase as the oscillator circuit signal and decreases in amplitude as the signal of the oscillator circuit increases.
Dependencies are inferred from the claim text.