Crystal oscillator emulator

• US 7,768,361 B2
• Filed: 04/03/2007
• Issued: 08/03/2010
• Est. Priority Date: 10/15/2002
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Sutardja, Sehat
• Primary Examiner(s): KINKEAD, ARNOLD M
• Application Number:
  US11/732,409
• Publication Number:
  US 20070182500A1
• Time in Patent Office: 1,218 Days
• Field of Search: 331/176, 331/158, 331/66
• US Class Current: 331/176
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11C 2029/5002 Characteristic
• CPC Class Codes: G11C 2207/2254 Calibration
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 7/04 with means for avoiding disturbances due to temperature effects
• CPC Class Codes: G11C 7/22 Read-write [R-W] timing or clocking circuits; Read-write [R-W] control signal generators or management
• CPC Class Codes: G11C 7/222 Clock generating, synchronizing or distributing circuits within memory device
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/315 the encapsulation having a cavity
• CPC Class Codes: H01L 23/34 Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 2924/16235 Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip
• CPC Class Codes: H01L 2924/166 Material
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H03B 5/04 : Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/30 : with frequency-determining element being electromechanical resonator
• CPC Class Codes: H03L 1/026 : by using a memory for digitally storing correction values H03L1/025 takes precedence
• CPC Class Codes: H03L 1/027 : by using frequency conversion means which is variable with temperature, e.g. mixer, frequency divider, pulse add/substract logic circuit H03L1/023, H03L1/026 take precedence
• CPC Class Codes: H03L 5/00 : Automatic control of voltage, current, or power
• CPC Class Codes: H03L 7/08 : Details of the phase-locked loop
• CPC Class Codes: H03L 7/0802 : the loop being adapted for reducing power consumption H03L7/14 takes precedence
• CPC Class Codes: H03L 7/0891 : the up-down pulses controlling source and sink current generators, e.g. a charge pump
• CPC Class Codes: H03L 7/197 : a time difference being used for locking the loop, the counter counting between numbers which are variable in time or the frequency divider dividing by a factor variable in time, e.g. for obtaining fractional frequency division H03L7/1806 takes precedence
• CPC Class Codes: H03L 7/1974 : for fractional frequency division
• CPC Class Codes: H03L 7/1976 : using a phase accumulator for controlling the counter or frequency divider

Abstract

An integrated circuit comprises a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes a semiconductor oscillator that generates resonator drive signal having a drive frequency and a MEMS resonator that receives the resonator drive signal. A temperature sensor senses a temperature of the integrated circuit. Memory stores calibration parameters and selects at least one of the calibration parameters as a function of the sensed temperature, wherein the drive frequency is based on the calibration parameters.

Claims

1. An integrated circuit comprising:

a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

a temperature sensor that senses a temperature of said integrated circuit;

memory that stores calibration parameters and that selects at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters;

a heater that adjusts said temperature to a predetermined temperature; and

a disabling circuit that disables said heater after said calibration parameters are stored in said memory.

4. The integrated circuit of claim 1 wherein said heater is selected from a group consisting of transistor heaters and resistive heaters.

2. An integrated circuit comprising:

a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

a temperature sensor that senses a temperature of said integrated circuit;

memory that stores calibration parameters and that selects at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

an adaptive calibration module that adaptively adjusts a calibration approach for generating said calibration parameters based on a number of temperature test points input thereto.

5. The integrated circuit of claim 2 wherein when test data consists of a single temperature test point, said adaptive calibration module employs at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

6. The integrated circuit of claim 2 wherein when test data consists of two temperature test points, said adaptive calibration module employs at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

7. The integrated circuit of claim 2 wherein when test data consists of two temperature test points, said adaptive calibration module adjusts at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

8. The integrated circuit of claim 2 wherein when said test data comprises three temperature test points, said calibration module adjusts at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

3. An integrated circuit comprising:

a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

a temperature sensor that senses a temperature of said integrated circuit;

memory that stores calibration parameters and that selects at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

a select input that selects said drive frequency as a function of an external passive component.

9. The integrated circuit of claim 3 wherein said memory includes one time programmable memory.

10. An integrated circuit comprising:

microelectromechanical (MEMS) means for generating a reference frequency and that includes;

semiconductor oscillating means for generating a resonator drive signal having a drive frequency; and

a MEMS resonator means for receiving said resonator drive signal and for resonating;

temperature sensing means for sensing a temperature of said integrated circuit; and

storing means for storing calibration parameters and for selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters;

heating means for adjusting said temperature to a predetermined temperature; and

disabling means for disabling said heating means after said calibration parameters are stored in said storing means.

13. The integrated circuit of claim 10 wherein said heating means is selected from a group consisting of transistor heaters and resistive heaters.

11. An integrated circuit comprising:

microelectromechanical (MEMS) means for generating a reference frequency and that includes;

semiconductor oscillating means for generating a resonator drive signal having a drive frequency; and

a MEMS resonator means for receiving said resonator drive signal and for resonating;

temperature sensing means for sensing a temperature of said integrated circuit; and

storing means for storing calibration parameters and for selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

adaptive calibration means for adaptively adjusting a calibration approach for generating said calibration parameters based on a number of temperature test points input thereto.

14. The integrated circuit of claim 11 wherein when test data consists of a single temperature test point, said adaptive calibration means employs at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

15. The integrated circuit of claim 11 wherein when test data consists of two temperature test points, said adaptive calibration means employs at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

16. The integrated circuit of claim 11 wherein when test data consists of two temperature test points, said adaptive calibration means adjusts at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

17. The integrated circuit of claim 11 wherein when said test data comprises three temperature test points, said adaptive calibration means adjusts at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve, and adjusts a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

12. An integrated circuit comprising:

microelectromechanical (MENS) means for generating a reference frequency and that includes;

semiconductor oscillating means for generating a resonator drive signal having a drive frequency; and

a MEMS resonator means for receiving said resonator drive signal and for resonating;

temperature sensing means for sensing a temperature of said integrated circuit; and

storing means for storing calibration parameters and for selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

select input means for selecting said drive frequency as a function of an external passive component.

18. The integrated circuit of claim 12 wherein said storing means includes one time programmable memory.

19. A method comprising:

providing a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

sensing a temperature of said integrated circuit; and

storing calibration parameters;

selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters;

adjusting said temperature to a predetermined temperature; and

disabling said heater after said calibration parameters are stored in said memory.

22. The method of claim 19 wherein said heater is selected from a group consisting of transistor heaters and resistive heaters.

20. A method comprising:

providing a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

sensing a temperature of said integrated circuit; and

storing calibration parameters;

selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

adaptively adjusting a calibration approach for generating said calibration parameters based on a number of temperature test points input thereto.

23. The method of claim 20 wherein when test data consists of a single temperature test point, further comprising:

employing at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve; and

adjusting a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

24. The method of claim 20 wherein when test data consists of two temperature test points, further comprising:

employing at least one of a slope of a predetermined temperature characteristic line and a curvature of predetermined temperature characteristic curve; and

adjusting a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

25. The method of claim 20 wherein when test data consists of two temperature test points, further comprising:

adjusting at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve; and

adjusting a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

26. The method of claim 20 wherein when test data comprises three temperature test points, further comprising:

adjusting at least one of a slope of a predetermined temperature characteristic line and a curvature of a predetermined temperature characteristic curve; and

adjusting a location of said at least one of said predetermined temperature characteristic line and said predetermined temperature characteristic curve based on said test data.

21. A method comprising:

providing a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

sensing a temperature of said integrated circuit; and

storing calibration parameters;

selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters;

selecting said drive frequency as a function of an external passive component.

27. The method of claim 21 wherein said memory includes one time programmable memory.

28. A method comprising:

providing a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

sensing a temperature of said integrated circuit; and

storing calibration parameters;

selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters;

providing an LC tank circuit;

providing cross-coupled transistors that communicate with said LC tank circuit;

monitoring an amplitude of an output of said semiconductor oscillator and generating a control signal based thereon; and

adjusting a current bias to said cross-coupled transistors based on said control signal.

29. An integrated circuit comprising:

a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes;

a semiconductor oscillator that generates resonator drive signal having a drive frequency; and

a MEMS resonator that receives said resonator drive signal;

a temperature sensor that senses a temperature of said integrated circuit;

memory that stores calibration parameters and that selects at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

wherein said semiconductor oscillator comprises;

an LC tank circuit;

cross-coupled transistors that communicate with said LC tank circuit;

an amplitude monitoring module that monitors an amplitude of an output of said semiconductor oscillator and that generates a control signal based thereon; and

a current bias adjusting module that adjusts a current bias to said cross-coupled transistors based on said control signal.

30. An integrated circuit comprising:

microelectromechanical (MEMS) means for generating a reference frequency and that includes;

semiconductor oscillating means for generating a resonator drive signal having a drive frequency; and

a MEMS resonator means for receiving said resonator drive signal and for resonating;

temperature sensing means for sensing a temperature of said integrated circuit; and

storing means for storing calibration parameters and for selecting at least one of said calibration parameters as a function of said sensed temperature,

wherein said drive frequency is based on said calibration parameters; and

wherein said semiconductor oscillating means comprises;

an LC tank circuit;

cross-coupled transistors that communicate with said LC tank circuit;

amplitude monitoring means for monitoring an amplitude of an output of said semiconductor oscillator and for generating a control signal based thereon; and

current bias adjusting means for adjusting a current bias to said cross-coupled transistors based on said control signal.