Oscillator frequency accuracy and amplitude control

Patent metadata

Field	Value
Publication number	US-12206361-B2
Application number	US-202218078723-A
Country	US
Kind code	B2
Filing date	Dec 9, 2022
Priority date	Dec 15, 2021
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

In examples, an electronic device comprises an oscillator circuit configured to provide an output signal and a controller coupled to the oscillator circuit. The controller is configured to receive first and second target rates; dynamically adjust a frequency accuracy of the output signal based on the first target rate; and dynamically adjust an amplitude of the output signal based on the second target rate.

First claim

What is claimed is:

1. An electronic device, comprising:
an oscillator circuit configured to provide an output signal; and
a controller coupled to the oscillator circuit and configured to:
receive first and second target rates;
dynamically adjust a frequency accuracy of the output signal based on the first target rate;
dynamically adjust an amplitude of the output signal based on the second target rate; and
interleave adjustments to the frequency accuracy and the amplitude to maintain energy in a crystal of the oscillator circuit within a target range.

2. The electronic device of claim 1 , wherein the oscillator circuit includes a variable capacitor, and wherein the controller is configured to dynamically adjust the frequency accuracy by adjusting the variable capacitor.

3. The electronic device of claim 1 , wherein the oscillator circuit includes a variable resistor, and wherein the controller is configured to dynamically adjust the amplitude by adjusting the variable resistor.

4. The electronic device of claim 1 , further comprising a second controller coupled to the oscillator circuit, the second controller configured to adjust a current mirror in the oscillator circuit to control the amplitude of the output signal.

5. The electronic device of claim 1 , wherein the oscillator circuit is a Pierce oscillator circuit.

6. The electronic device of claim 1 , wherein dynamically adjusting the frequency accuracy of the output signal comprises monotonically adjusting a capacitance of a variable capacitor of the oscillator circuit.

7. The electronic device of claim 1 , wherein dynamically adjusting the amplitude of the output signal comprises monotonically adjusting a current flowing through the oscillator circuit.

8. An electronic device, comprising:
an oscillator circuit including a first adjustable component configured to control a frequency accuracy of an output signal of the oscillator circuit and a second adjustable component configured to control an amplitude of the output signal; and
a controller coupled to the oscillator circuit and configured to:
adjust a first value of the first adjustable component to a first target value at a first rate that does not exceed a first threshold rate, wherein the first target value and first threshold rate are dynamically adjustable inputs to the controller; and
adjust a second value of the second adjustable component to a second target value at a second rate that does not exceed a second threshold rate, wherein the second target value and the second threshold rate are dynamically adjustable inputs to the controller.

9. The electronic device of claim 8 , wherein the oscillator circuit is a crystal oscillator circuit.

10. The electronic device of claim 8 , wherein the oscillator circuit is a Pierce oscillator circuit.

11. The electronic device of claim 8 , wherein the first adjustable component is a variable capacitor coupled to an amplifier of the oscillator circuit.

12. The electronic device of claim 8 , wherein the second adjustable component is a variable resistor configured to provide a variable resistance.

13. The electronic device of claim 8 , further comprising a second controller configured to control the amplitude of the output signal by adjusting a current mirror of the oscillator circuit, the current mirror coupled to an amplifier of the oscillator circuit.

14. The electronic device of claim 8 , wherein the first threshold rate includes a step size and a time increment, the step size indicating a maximum permissible change in the first value toward the first target value per instance of the time increment.

15. The electronic device of claim 8 , wherein the controller is configured to interleave adjustments to the first adjustable component with adjustments to the second adjustable component to maintain energy in a crystal of the oscillator circuit within a target range.

16. A method, comprising:
receiving a first target value and a first threshold rate for a frequency accuracy of an oscillator output signal;
receiving a second target value and a second threshold rate for an amplitude of the oscillator output signal;
adjusting a first value of the frequency accuracy of the oscillator output signal toward the first target value at a rate less than or equal to the first threshold rate; and
adjusting a second value of the amplitude of the oscillator output signal toward the second target value at a rate less than or equal to the second threshold rate.

17. The method of claim 16 , wherein the first threshold rate includes a step size and a time increment, the step size indicating a maximum permissible change in the first value toward the first target value per instance of the time increment.

18. The method of claim 16 , further comprising receiving a time increment and delaying the adjustment of the first value by the time increment.

19. The method of claim 16 , wherein adjusting the first value includes adjusting a variable capacitor coupled to an amplifier in an oscillator, the oscillator configured to output the oscillator output signal.

20. The method of claim 19 , wherein adjusting the second value includes adjusting a variable resistor configured to provide a variable resistance in the oscillator.

21. The method of claim 19 , further comprising interleaving adjustments to the first value with adjustments to the second value to maintain energy in a crystal of the oscillator within a target range.

Assignees

• Texas Instruments Inc

Inventors

• Graf Hagen
• Griffith Danielle

Classifications

• H03B5/04

  Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature · CPC title

• H03B2200/0038

  including a current mirror · CPC title

• H03B2200/0012

  Pierce oscillator · CPC title

• H03B2201/031

  the parameter being the amplitude of a signal, e.g. maintaining a constant output amplitude over the frequency range · CPC title

• H03B5/362 Primary

  the amplifier being a single transistor (H03B5/364 - H03B5/368 take precedence) · CPC title