Integrated CMOS high precision piezo-electrically driven clock

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.

1 . 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;    at least one sensor formed on the substrate to sense at least one environmental parameter of the integrated circuit; and    a microprocessor coupled to the clock generator and the at least one sensor to process the at least one environmental parameter and adjust the frequency of the clock generator based on the at least one environmental parameter.    
     
     
         2 . The integrated circuit of  claim 1 , further comprising a plurality of sensors including a temperature sensor, a hot electron sensor, and a shock sensor.  
     
     
         3 . The integrated circuit of  claim 1 , further comprising a primary oscillator coupled to the clock generator to be calibrated by the frequency of the clock generator.  
     
     
         4 . The integrated circuit of  claim 1 , wherein the at least one environmental parameter includes temperature and supply voltage.  
     
     
         5 . The integrated circuit of  claim 1 , wherein the at least one sensor includes one or more supply voltage sensors.  
     
     
         6 . The integrated circuit of  claim 1 , wherein the piezoelectric resonator comprises an integrated piezo-electric film formed on the substrate.  
     
     
         7 . The integrated circuit of  claim 1 , wherein the piezoelectric resonator comprises an integrated ZnO film formed on the substrate.  
     
     
         8 . The integrated circuit of  claim 1 , wherein the piezoelectric resonator further comprises a doped polysilicon cantilever deposited over a pit of the substrate.  
     
     
         9 . The integrated circuit of  claim 1 , wherein the microprocessor is to further perform processing tasks unrelated to the clock generator.  
     
     
         10 . The integrated circuit of  claim 1 , wherein the microprocessor comprises a central processing unit.  
     
     
         11 . A method comprising: 
 receiving information regarding environmental parameters of an integrated circuit from at least one sensor formed on a substrate of the integrated circuit, the integrated circuit including a shock sensor;    processing the information in a central processor formed on the substrate to generate control signals; and    adjusting a frequency of a clock oscillator formed on the substrate using the control signals, wherein the clock oscillator comprises a resonator including a piezoelectric film formed on the substrate.    
     
     
         12 . The method of  claim 11 , further comprising adjusting a delay value of a ring oscillator based on the information, wherein the information relates to an operating voltage of the integrated circuit.  
     
     
         13 . The method of  claim 1   1 , 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.    
     
     
         14 . The method of  claim 13 , further comprising adjusting the frequency of the clock oscillator when the temperature result is out of the predetermined range.  
     
     
         15 . A system 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 parameter of the system and including a temperature sensor and a shock sensor; and    a central processing unit coupled to the plurality of sensors, the central processing unit configured to process an output of the plurality of sensors and to control the controlled oscillator based on the output at least some of the plurality of sensors.    
     
     
         16 . The system of  claim 15 , wherein the silicon piezoelectric resonator comprises a portion of a substrate having a doped layer located thereon and wherein the portion of the substrate is undercut.  
     
     
         17 . The system of  claim 15 , wherein the controlled oscillator, the plurality of sensors and the central processing unit are formed on a single substrate.  
     
     
         18 . The system of  claim 15 , wherein the system comprises a portable device.  
     
     
         19 . The system of  claim 18 , wherein the portable device comprises a cellular telephone.  
     
     
         20 . The system of  claim 15 , further comprising a hot electron sensor comprising a transistor having an output terminal coupled to output a signal to the central processing unit and a gate terminal to control the transistor based on an output of the central processing unit.