Systems and methods for temperature compensated oscillators having low noise

Patent metadata

Field	Value
Publication number	US-9577647-B2
Application number	US-201514700739-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Apr 30, 2015
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A voltage controlled oscillator arrangement is disclosed. The arrangement includes a voltage controlled oscillator and a bypass component. The voltage controlled oscillator has an output and a tuning port. The output provides an output signal at an operating frequency. The tuning port is configured to select the operating frequency according to an applied voltage. The voltage controlled oscillator has active portions and inactive portions. During the active portions, the output signal is at a non-zero value. The bypass component is configured to apply a bypass compensating signal to the tuning port during the active portions of the voltage controlled oscillator. The bypass compensating signal compensates for an oscillator temperature of the voltage controlled oscillator.

First claim

What is claimed is:

1. A voltage controlled oscillator arrangement comprising:
a voltage controlled oscillator having an output and a tuning port, wherein the output provides an output signal at an operating frequency, the tuning port is configured to select the operating frequency of the output signal according to an applied voltage, the voltage controlled oscillator is supplied by a supply voltage, wherein the supply voltage is OFF during inactive portions of a cycle and the supply voltage is ON during active portions of the cycle;
a bypass component configured to apply a bypass compensating signal to the tuning port during the active portions of the cycle and the bypass component is configured to be charged during the inactive portions of the cycle, wherein the bypass compensating signal compensates for an oscillator temperature of the voltage controlled oscillator; and
wherein the bypass component is configured to have a positive to ambient temperature (PTAT) compensation applied only during the inactive portions of the cycle for the supply voltage of the voltage controlled oscillator.

2. The arrangement of claim 1 , wherein the bypass component is a passive component.

3. The arrangement of claim 1 , wherein a duty cycle of the supply voltage for the voltage controlled oscillator is configured to mitigate power consumption and the active portions are shorter than the inactive portions.

4. A voltage controlled oscillator arrangement comprising:
a voltage controlled oscillator having an output and a tuning port, wherein the output provides an output signal at an operating frequency, the tuning port is configured to select the operating frequency of the output signal according to an applied voltage, the voltage controlled oscillator is supplied by a supply voltage, wherein the supply voltage is OFF during inactive portions of a cycle and the supply voltage is ON during active portions of the cycle;
a bypass component configured to apply a bypass compensating signal to the tuning port during the active portions of the cycle and the bypass component is configured to be charged during the inactive portions of the cycle, wherein the bypass compensating signal compensates for an oscillator temperature of the voltage controlled oscillator; and
a positive to ambient temperature (PTAT) component configured to generate and provide a PTAT compensation to the bypass component only during the inactive portions of the cycle for the supply voltage of the voltage controlled oscillator.

5. The arrangement of claim 4 , wherein the PTAT component is disabled during the active portions of the cycle for the supply voltage of the voltage controlled oscillator.

6. The arrangement of claim 4 , wherein the PTAT component determines a temperature compensation coefficient for the voltage controlled oscillator.

7. The arrangement of claim 4 , wherein the PTAT component is configured to generate the PTAT compensation according to the oscillator temperature.

8. The arrangement of claim 4 , wherein the PTAT component is disabled by a disable/enable signal applied to an enable terminal of the PTAT component.

9. The arrangement of claim 4 , wherein the PTAT component is supplied by a PTAT supply voltage.

10. The arrangement of claim 9 , further comprising an inverter to invert the supply voltage for the voltage controlled oscillator to the PTAT supply voltage for the PTAT component.

11. A sensor arrangement having a low temperature coefficient comprising:
a mixer path configured to receive an input signal and generate a mixed signal from the input signal;
a voltage controlled oscillator configured to generate an oscillator output based on an oscillator input voltage, wherein the voltage controlled oscillator is supplied by a supply voltage, where the supply voltage is OFF during inactive portions of a cycle and is ON during active portions of the cycle;
an amplifier path configured to generate an output signal from the oscillator output;
a bypass component configured to apply a bypass compensating signal to the oscillator input voltage during the active portions of the cycle for the supply voltage of the voltage controlled oscillator; and
a positive to ambient temperature (PTAT) component configured to generate a PTAT compensation and charge the bypass component with the PTAT compensation during the inactive portions of the cycle for the supply voltage of the voltage controlled oscillator, wherein the PTAT component is disabled during the active portions of the cycle for the supply voltage of the voltage controlled oscillator.

12. The arrangement of claim 11 , wherein the oscillator output is at a stable operating frequency independent of a temperature of the voltage controlled oscillator.

13. The arrangement of claim 11 , wherein the bypass component includes a capacitor.

14. The arrangement of claim 11 , wherein the bypass compensating signal of the bypass component modifies the oscillator input voltage by a compensating voltage that compensates for temperature drift.

15. A method of operating an oscillator, the method comprising:
applying a tuning voltage to an input of the oscillator according to an operating frequency;
determining a temperature compensation coefficient for the oscillator;
determining and generating a positive to ambient temperature (PTAT) compensation based on the temperature compensation coefficient and a current temperature of the oscillator during an inactive portion of a cycle for a supply voltage of the oscillator;
providing the supply voltage to the oscillator, wherein the supply voltage is OFF during the inactive portion of the cycle and the supply voltage is ON during an active portion of the cycle;
charging a bypass component only during the inactive portion of the cycle for the supply voltage of the oscillator by the PTAT compensation; and
applying a bypass compensating signal to a tuning port of the oscillator by the bypass component to compensate for temperature variations of the oscillator.

16. The method of claim 15 , wherein the bypass component determines the temperature compensation coefficient based on testing an oscillator output at various temperatures.

17. The method of claim 15 , wherein generating the PTAT compensation includes introducing noise in the PTAT compensation.

18. The method of claim 17 , wherein the bypass compensating signal is free of the introduced noise.

Assignees

• Infineon Technologies Ag

Inventors

• Forstner Johann Peter

Classifications

• H03L1/022 Primary

  by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature (H03L1/021 takes precedence) · CPC title

• H03L1/02 Primary

  against variations of temperature only · CPC title

• H03B5/04 Primary

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

• H03L7/099

  concerning mainly the controlled oscillator of the loop · CPC title

• H03B5/36

  active element in amplifier being semiconductor device ({H03B5/323, H03B5/326} , H03B5/38 take precedence) · CPC title