FPGA Controlled Amplifier Module May Team Members  Jesse Bartley, CprE  Jiwon Lee, EE  Michael Hayen, CprE  Zhi Gao, EE Client: Teradyne Corp. Faculty advisor: Dr. Chris Chu April 25th, 2006

Presentation Outline Introductory Materials Project Activity Description  Design Overview  Implementation  Testing Resources and Schedules Closing Materials May 06-14

List of Terms and Definitions Bill of Materials – List of Components and their cost DAC – Conversion of a digital signal to an analog sampled signal DC-offset – given signal source does not have the correct 0- crossing but shifted down or up. FPGA – Field programmable gate arrays, allows us to control some the circuits automatically Gain – The ratio of the output amplitude to the input amplitude HDL – Hardware Description Language Noise – Undesired interference in signals Spectrum Analyzer – A computer-based tool that analyzes signals in the frequency domain THD – Total harmonic distortion, the ratio between the powers of all harmonic frequencies above the fundamental frequency May 06-14

Acknowledgement Teradyne Corporation  Jacob Mertz  Ramon De La Cruz  Steven Miller Additional Help  Jason Boyd  Dr. Robert Weber May 06-14

Problem statement:  To build and test the FPGA controlled Amplifier for PC based Spectrum Analyzer developed by previous team Approach:  Understand existing design  Board assembly and bring-up  Make detailed test plan  Perform and document tests Problem Statement & Approach

Users, Uses & Operating Environment Primary users  Engineers at the Teradyne Corporation Product function  As a pre-amplifier for the signal input to a PC based spectrum analyzer device.  PC based spectrum analyzer was designed by previous phase Climate-controlled laboratory (low humidity)  ESD (Electro Static Discharge) May 06-14

Assumptions and Limitations Assumptions  The end product will not be sold to other companies.  The design provided by the previous team is valid.  Necessary equipment will be available. Limitations  Equipment must be available on campus  The design must meet specifications May 06-14

Previous Accomplishments General Design Untested FPGA code Design Schematic Bill of Materials Partial assembly of board May 06-14

Present Accomplishments Ordered parts and assembled board Researched and verified design Re-vamped FPGA code Made detailed test plans Developed automated tests Identified and resolved board errors May 06-14

End Product & Other Deliverables An assembled board Updated design Completed test plans Automated LabVIEW tests Documentation of all activities May 06-14

Approaches Considered and one used Approaches considered:  Manual testing and calculation  LabVIEW automated testing and Excel calculation Choice: LabVIEW automated testing  Repeatability  Self documentation  Speed/efficiency  Extra research required May 06-14

Project Definition Activities Goals of this project:  Research & verify the previous design  Meet the specifications  Board Assembly  Make a detailed test plan  Testing  Document all processes May 06-14

Research Activities Study previous team’s design Pspice simulation Test methodologies  Noise  THD LabVIEW May 06-14

Design Activities Verification of design  DC Offset Correction  Operational Amplifier Tests design  DC Offset Correction verification tests  Amplifier performance tests May 06-14

Circuit Overview May 06-14

Implementation Activities Errors on the PCB were fixed New Pspice Simulation was developed Trouble shoot for unexpected oscillation Specifications were adjusted Test strategy was developed according to Client suggestions May 06-14

PCB Board Adjustments New parts purchased and soldered Pins of voltage regulators switched Pins of op-amps switched Fixed incorrect supply voltage FPGA code fixed May 06-14

Unexpected Oscillation Frequency: 32 – 60MHz Amplitude: 5-10Vpp Potential causes  External Noise  Error in assembly  Parasitic capacitances  Unstable amplifier design May 06-14

Unexpected Oscillation May 06-14

Cause of Oscillations External Noise  Twisted wires at inputs  Tested in alternate location/alternate equipment Error in assembly  Corrected error with voltage regulators in layout  All essential parts replaced Parasitic capacitances  PSPICE models also showed oscillations (without capacitors) Other debugging  DC offset correction adjusted  Comparator circuit disconnected  Both current feedback and voltage feedback amps Conclusion - Unstable amplifier design May 06-14

Pspice Simulation Developed in Orcad Student 9.1 Purposes  Help determine new specifications  Help find new resistor values  Help troubleshooting May 06-14

PSPICE Model May 06-14

PSPICE Simulation R1R2R3R4 6dB dB 221 2k k 40dB 10 1k10k4.99k 60dB 10 10k7.15k20k New resistors:  Maximize the bandwidth  Achieve best response flatness May 06-14

Changed Specification DC — 1kHz+/- 5 volts6, 20, 40, 60+/- 10 volts0.5 dB< dB1.5 nV/rtHz > 1kHz - 20 kHz+/- 5 volts6, 20, 40, 60+/- 10 volts0.5 dB< - 95 dB1.5 nV/rtHz > 20kHz - 100kHz+/- 2.5 volts6, 20, 40+/- 5 volts0.50 dB< -85 dB2.5 nV/rtHz > 100kHz - 1MHz+/- 2.5 volts6, 20, 40+/- 5 volts0.50 dB< - 80 dB3.5 nV/rtHz > 1MHz - 10MHz+/- 2.5 volts6, 20, 40+/- 5 volts0.50 dB< - 70 dB3.5 nV/rtHz > 10MHz - 20MHz+/- 2.5 volts6, 20+/- 5 volts0.50 dB< -65 dB3.5 nV/rtHz > 20MHz - 50MHz+/- 1.0 volts6, 20+/- 2.0 volts1.00 dB< -50 dB5.0 nV/rtHz > 50MHz - 100MHz+/- 1.0 volts6, 20+/- 2.0 volts2.10 dB< -40 dB5.0 nV/rtHz Input Total InputVoltageAvailableMax OutputFreq ResponseHarmonic FrequencyRangeGain SettingsVoltageFlatnessDistortionNoise Range(Volts)(dB)(Volts)(dB) (nV/rtHz) May 06-14

Testing Goal: verify compliance with specifications Important considerations  Documentation  Usability  Repeatability Automated Testing  LabVIEW  Data stored in Excel May 06-14

Testing (Cont.) Tests  DC gain test  Gain flatness and bandwidth test  Total harmonic distortion test  Circuit noise test  VHDL code behavior test  DAC control test  Offset calibration test  Offset correction verification test } } Amplifier Tests DC Offset Tests May 06-14

Amplifier Tests DC Gain Test  Pure measure of DC gain  No AC effects Gain Flatness and Bandwidth Test  AC input across 0-100MHz range  Verify flatness is within specification  Ensures consistent gain Total Harmonic Distortion  THD = Distortion at multiples of input frequency  Performed with spectrum analyzer Noise Test  Ambient noise created by op-amps  Also measured by spectrum analyzer May 06-14

DC Offset Tests VHDL Behavior Test  Tests just behavior of algorithm  Simulated on PC in ModelSim DAC Control Test  Custom FPGA code  Ensures DAC produces correct offsets  Performed in circuit Offset Calibration  Artificially inject range of offsets  Calibrate for each, verify correction Offset Correction Verification Test  Ensure calibration holds when AC signal is applied  Final assurance individual systems work well together May 06-14

LabVIEW Code

Personnel Effort Requirements May Task 1 – Problem definition Task 2 – Research previous phases to understand the designs project Task 3 – Identify errors and documentation Task 4 – Test plan design Task 5 – Assemble board and bring up Task 6 – LabVIEW development and Testing Task 7 – Final report and presentation Personnel Name Task 1 (hours) Task 2 (hours) Task 3 (hours) Task 4 (hours) Task 5 (hours) Task 6 (hours) Task 7 (hours) Totals (hours) Jesse Bartley Jiwon Lee Michael Hayen Zhi Gao Totals (hours)

Financial Requirement May ItemWithout LaborWith Labor($11.00/hour) Components$72.32 Project Poster$30 Project Plan$0 Labor at $11.00/hour oJesse Bartley $0 $2,079 oJiwon Lee $0 $1,914 oMichael Hayen $0 $1,507 oZhi Gao $0 $1,958 Total Cost $ $7,560.32

Project Evaluation NumberMilestoneImportanceProgress 1Understand previous project HighMet 2FPGA codeHighMet 3Assemble boardHighMet 4Test plan developmentHighMet 5Document all progressHighMet 6Identify problemsHighMet 7TestsMediumPartially Met May 06-14

Project Schedules May 06-14

Project Archive Folder May 06-14

Additional Work Recommended work  Correct design to eliminate oscillations  Re-build prototype board accordingly  Verify specifications with LabVIEW tests  FPGA control of gain  Frequency response calibration Future integration with Spectrum Analyzer  Once above recommendations are met May 06-14

Commercialization Recommended additional work required Packaged with PC based spectrum analyzer Price to be determined Potential Market  Small technology companies May 06-14

Lessons Learned Experience gained  Documentation methods  Team Work  Working with an outside client  Following schedules  Test procedures  Test implementation  LabVIEW development May 06-14

Risk and Management Unexpected test results  Conduct proper trouble shooting Loss of a team member (Did not encounter)  Work cooperatively  Good communication  Keep updating all processes on the website Hardware Damage  Quick replacement and backup board Design Problem  Identify the problem and suggest for the next phase Specifications not practical  Define new specifications (with client input) May 06-14

Closing Summary Team’s Accomplishments  Assembled the prototype  Developed FPGA code  Developed Test plans and LabVIEW programs  Documented and organized work  Debugged the product and identified problems Project will make contribution  Teradyne  PC-Based Spectrum Analyzer Product The team received the following benefits:  Technical knowledge  Team work  Real industry project Overall, project benefits both the client and the team May 06-14

Questions? May 06-14