Integrated CMOS high precision piezo-electrically driven clock

• US 7,098,748 B2
• Filed: 09/21/2001
• Issued: 08/29/2006
• Est. Priority Date: 09/21/2001
• Status: Expired due to Fees

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Gallitzin Allegheny LLC (Intellectual Ventures LLC)
• Inventors: Schmidt, Dominik J.
• Primary Examiner(s): LAM, TUAN THIEU
• Application Number:
  US09/962,937
• Publication Number:
  US 20030058057A1
• Time in Patent Office: 1,803 Days
• Field of Search: 331/176
• US Class Current: 331/176
• CPC Class Codes: H03L 1/00 Stabilisation of generator output against variations of physical values, e.g. power supply
• CPC Class Codes: H03L 1/025 and a memory for digitally storing correction values
• CPC Class Codes: H03L 1/028 of generators comprising piezoelectric resonators H03L1/021, H03L1/022 take precedence; oscillation generators with a piezoelectric resonator H03B5/32
• CPC Class Codes: H03L 1/04 Constructional details for maintaining temperature constant

Abstract

A clock oscillator embedded in an integrated circuit, including a piezoelectric resonator formed on the integrated circuit; a clock generator coupled to the on-chip piezoelectric resonator, one or more sensors adapted to sense one or more environmental parameters affecting the piezoelectric resonator; and a processor coupled to the clock generator and the one or more sensors to adjust the frequency of the clock generator based on the one or more environmental parameters.

Claims

1. A clock oscillator embedded in an integrated circuit, comprising:

a piezoelectric resonator formed on a substrate of the integrated circuit;

a clock generator formed on the substrate and coupled to the piezoelectric resonator;

sensors adapted to sense one or more environmental parameters affecting the piezoelectric resonator, the one or more sensors including a temperature sensor, a hot electron sensor, and a shock sensor;

a processor coupled to the clock generator and the sensors and adapted to process the one or more environmental parameters and adjust the frequency of the clock generator based on the one or more environmental parameters; and

a primary oscillator coupled to the clock generator to be calibrated by the frequency of the clock generator.

2. The oscillator of claim 1, wherein the environmental parameters includes temperature and supply voltage.

3. The oscillator of claim 1, wherein the sensors include one or more supply voltage sensors.

4. The oscillator of claim 1, wherein the piezoelectric resonator comprises an integrated piezo-electric film formed on the substrate.

5. The oscillator of claim 1, wherein the piezoelectric resonator comprises an integrated ZnO film formed on the substrate.

6. The oscillator of claim 1, wherein the piezoelectric resonator further comprises a doped polysilicon cantilever deposited over a pit of the substrate.

7. The oscillator of claim 6, further comprising a polysilicon layer deposited and patterned and a boron layer implanted into the polysilicon layer, wherein the polysilicon layer is undercut.

8. The oscillator of claim 1, wherein the hot electron sensor comprises a plurality of diodes to be reversed biased to sense hot electrons.

9. The oscillator of claim 1, wherein the primary oscillator comprises a ring oscillator coupled to an oscillator stage, the oscillator stage having an output to drive a phase locked loop.

10. The clock oscillator of claim 1, wherein the processor comprises a central processing unit.

11. A method comprising:

receiving information regarding environmental parameters of an integrated circuit from formed on a substrate of sensors, wherein the integrated circuit includes a temperature sensor, a hot electron sensor, and a shock sensor;

processing the information in a processor of the substrate to generate control signals;

adjusting a frequency of a clock oscillator formed on the substrate using the control signals, wherein the clock oscillator includes a piezoelectric resonator formed on the substrate; and

adjusting a delay value of a ring oscillator based on the information, wherein the information relates to an operating voltage of the integrated circuit.

12. The method of claim 11, further comprising:

receiving temperature information from multiple temperature sensors of the integrated circuit;

manipulating the temperature information into a temperature result; and

comparing the temperature result to a predetermined range.

13. The method of claim 12, further comprising adjusting the frequency of the clock oscillator when the temperature result is out of the predetermined range.

14. An integrated circuit (IC) comprising:

a controlled oscillator including a silicon piezoelectric resonator;

a plurality of sensors coupled to the controlled oscillator, the plurality of sensors each configured to sense an operating parameters of the IC and including a temperature sensor, a hot electron sensor, and a shock sensor; and

a processor coupled to the plurality of sensors, the processor configured to process an output of the plurality of sensors and to control the controlled oscillator based on the output of the plurality of sensors.

15. The IC of claim 14, wherein the silicon piezoelectric resonator comprises a portion of a substrate of the IC having a doped layer located thereon and wherein the portion of the substrate is undercut.

16. The IC of claim 14, wherein the controlled oscillator, the plurality of sensors and the processor are formed on a single substrate.