1. Crystal Oscillator Negative Resistance Measurement System Cypress-R Team Members Tracey Windley Adam El-Mansouri Mentor Dr. Herb Hess Client Contact Aaron Brennan

2. Overview Background Project Definition Theoretical Measurement Methods Simulation Results Proposed Instrumentation Setup Project Pert Chart Project Timeline Budget Identified Risks Summary

3. Background What is the negative resistance(-R) of an oscillator? –The -R of an oscillator is the amount of volts per ampere the circuit can deliver to the crystal. Startup negative resistance determines if the oscillator will start oscillation when the system is powered up.

4. Background Trade-offs exist between performance parameters of a crystal oscillator. Phase noise Jitter Frequency Negative resistance There is no industry standard for measuring –R. Customers complain if they believe the –R spec is not met. Difficult to accurately measure –R which leads to over-designing. Over-designing for –R to satisfy poor measurement methods results in sacrificing other oscillator performance parameters.

5. Cypress Crystal Oscillator Block Diagram

6. Project Definition Goal –Design a negative resistance measurement system for Cypress crystal oscillator circuits. Requirements –Better than 90% correlation between measured and simulation data. –The measurement system must be automated. –Compatibility with the Thermonics temperature control chamber and I2C programming interface utilized by Cypress. –Compatible with multiple oscillator chips. Deliverables –Testbench measurement system. –Measurement procedure with an instruction manual.

7. Theoretical Measurement Methods Basic 3-Point Oscillator:

8. Theoretical Measurement Methods Method 1 –Based on feedback analysis. 1.Measure input impedance while AC grounding Xout. 2.Measure output impedance while AC grounding Xin.

9. Theoretical Measurement Methods 3. Measure the voltage gain of the amplifier between Xin and Xout.

10. Theoretical Measurement Methods Method 2 1.Measure the feedback impedance Z f. 2.Use network analyzer to measure the H- parameters of the circuit. 3.From the H-parameters solve for Z1, Z2, and gm. 4.Use the Vittoz results to calculate the –R.

11. Simulation Results Method 1 Method 2 –Has not been verified yet in simulation.

12. Pros/Cons of the Methods Based on our current knowledge: Method 1Method 2 ProsConsProsCons Equipment will be hear Purchase impedance analyzer kit Already have equipment in Seattle May have to go to Seattle Easier to understand Requires disconnecting during measurement 2 port method and doesn’t require disconnect May load the circuit

13. Proposed Instrumentation Setup Agilent 4395A Network/Impedance/Spectrum Analyzer –Method 1 will require 43961A RF Impedance Test kit and coupling capacitors –Method 2 will require a H-parameter measurement setup Learn RF Measurement Theory

14. Project Pert Chart

15. Project Timeline

16. Budget Network Analyzer still under economic analysis –Waiting on quote from Agilent for Lease pricing

17. Identified Risks Lack of RF measurement knowledge –Summer will afford some time to come up to speed Package Parasitics/Network Analyzer Loading –Strive for a 50Ω system test fixture to minimize error from Network Analyzer Economic Analysis not yet complete –Will be completed in 2 weeks and a memo will be submitted. Equipment will need to be purchased/leased with a slight possibility of failure.

18. Summary -R background Project Definition Measurement theory and instrumentation setup Project schedule, timeline, and budget Identified risks

19. Questions ?