Oscillators having arbitrary frequencies and related systems and methods
Systems and methods for operating with oscillators configured to produce an oscillating signal having an arbitrary frequency are described. The frequency of the oscillating signal may be shifted to remove its arbitrary nature by application of multiple tuning signals or values to the oscillator. Alternatively, the arbitrary frequency may be accommodated by adjusting operation one or more components of a circuit receiving the oscillating signal.
1. An apparatus, comprising:
an oscillator located on a first semiconductor die and configured to output from the first semiconductor die a first oscillating signal, the first oscillating signal having a first frequency differing from a target frequency for the first oscillating signal by an offset, the oscillator comprising a memory located on the first semiconductor die, the memory being configured to store and output a value identifying the first frequency of the first oscillating signal or the offset; and
a system comprising a frequency synthesizer located on a second semiconductor die, the frequency synthesizer being configured to receive the first oscillating signal from the oscillator located on the first semiconductor die and to generate a second oscillating signal having a second frequency,
wherein the system is configured to receive from the memory located on the first semiconductor die the value identifying the first frequency of the first oscillating signal or the offset, wherein the system is further configured to select a setting of the frequency synthesizer based on the value received from the memory located on the first semiconductor die, and wherein a sub-system of the system is configured to receive the second oscillating signal and is configured to apply a tuning signal to the oscillator.
2. The apparatus of claim 1 , wherein the frequency synthesizer is a phase-locked loop (PLL) or a direct digital synthesizer (DDS).
3. The apparatus of claim 2 , wherein the first frequency of the first oscillating signal differs from the target frequency by at least 30 parts per million (ppm).
4. The apparatus of claim 3 , wherein the first frequency of the first oscillating signal differs from the target frequency by between approximately 1,000 ppm and 10,000 ppm, and wherein the system is configured to select the setting of the frequency synthesizer based on the value received from the memory located on the first semiconductor die such that the second frequency is within approximately 30 ppm of a target frequency for the second frequency.
5. The apparatus of claim 2 , wherein the oscillator comprises a mechanical resonator configured to produce the first oscillating signal.
6. The apparatus of claim 2 , wherein the frequency synthesizer is a PLL.
7. The apparatus of claim 6 , wherein the frequency synthesizer is a fractional PLL.
8. The apparatus of claim 2 , wherein the frequency synthesizer is a DDS.
9. The apparatus of claim 2 , wherein the value identifying the first frequency of the first oscillating signal or the offset identifies the offset.
10. The apparatus of claim 2 , wherein the value identifying the first frequency of the first oscillating signal or the offset identifies the first frequency.
11. The apparatus of claim 2 , wherein the system includes a first input port configured to receive from the oscillator the first oscillating signal, and wherein the system further includes a second input port configured to receive from the memory the value identifying the first frequency of the first oscillating signal or the offset.
12. The apparatus of claim 2 , wherein the oscillator comprises a mechanical resonator, wherein the system includes a first input port configured to receive from the oscillator the first oscillating signal, and wherein the system further includes a second input port configured to receive from the memory the value identifying the first frequency of the first oscillating signal or the offset, wherein the first frequency of the first oscillating signal differs from the target frequency by between approximately 1,000 ppm and 10,000 ppm, and wherein the system is configured to select the setting of the frequency synthesizer based on the value received from the memory located on the first semiconductor die such that the second frequency is within approximately 30 ppm of a target frequency for the second frequency.
13. The apparatus of claim 12 , wherein the frequency synthesizer is a fractional PLL.