Frequency to voltage


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Frequency to voltage

  1. 1. FREQUENCY TO VOLTAGECONVERTERByPrashant singhimi2011003
  2. 2. TABLE OF CONTENT1.Introduction.2.Basic FVC.3.Proposed FVC.4.Block Diagram.5.Hardware description.6.Advantage.7.Disadvantage.8.Conclusion.
  3. 3. INTRODUCTION Electronic devices that generate an output voltageor current proportional to the frequency ofsinusoidal input signal. It include op-amp for signal processing and RCnetwork for removing frequency-dependentripples.
  4. 4. BASIC FVC This is realized by a differentiator, an integrator, adivider and a square-rooter.A 1-4 GHz Frequency-to-Voltage Converter Design Department of Electronics Engineering, National Chiao -TungUniversity, 1001 University Road, Hsinchu, Taiwan
  5. 5. CONT.. The division of the differentiator output to theintegrator output causes large spikes when aninitial value of the integrator is not zero. Here output is proportional to input frequencywithout the influence of the input power.
  6. 6. PROPOSED FREQUENCY TO VOLTAGECONVERTER It is composed of a differentiator, two RMS-DCconverters, and a divider. Both include a frequency discrimination path andinput power calibration paths. In the frequency discrimination path, the inputfrequency was discriminated by an integrator ordifferentiator, respectively.
  7. 7. CONT… The RMS-DC converter is used to detect theoutput amplitude of the integrator or differentiator. In the input power calibration paths, which areonly composed of a RMS-DC converter for inputpower level detection. Finally, the current or voltage dividers are used toacquire the value of the input frequency.
  8. 8. Basic Block Diagram
  9. 9. Detailed StructureProposed block diagram[2]
  10. 10.  Frequency discrimination path contains anintegrator or differentiator and RMS-DC converter. the input frequency is discriminated by anintegrator or differentiator Output amplitude of the integrator or differentiatoris discriminated by RMS-DC converter. Input power calibration path detects input powerlevel .
  11. 11.  Current or voltage dividers are used to get thevalue of the input frequency. Frequency discrimination converts the signal to aDC voltage Vf by power detection. Composed of an attenuator and another powerdetector, the input power calibration path gives aDC voltage (Vcal) as a reference to calibrate thesignal amplitude
  12. 12. CONT.. The input signal is a pure sinusoidal signal with apeak amplitude of A and input frequency of ωn.
  13. 13.  The derivative of this signal at the output of thedifferentiator will be -where τd is the time constant of the differentiator. Feeding Vin(t) and Vd(t) into the RMS-DCconverters yields the results as-
  14. 14.  Dividing (4) by (3) we get- where k=kdiv τd is the sensitivity of the converterand kdiv is the scaling factor (gain) of the divider. The output signal is linearly proportional to theinput frequency, ωn , and insensitive to the inputsignal amplitude, A.
  15. 15. BLOCK DIGRAM CONT..Simple and Accurate Frequency to Voltage Converter A. Lorsawatsiri1, W. Kiranon1, V. Silaruam2, W. Sangpisit1, and P. Wardkein1 1 Faculty ofEngineering, King Mongkut’s Institute of Technology Ladkrabang Ladkrabang, Bangkok 10520, THAILAND
  16. 16. HARDWARE DESCRIPTION 5 operational amplifiers and 3 analog multipliersare used. One of the op-amp is used for performing thedifferentiator. The time constant of the differentiator,τd can be setby adjusting the resistor, R1 , and/or the capacitor,C1 , values. Other operational amplifiers are connected withmultipliers to realize RMS-DC converters
  17. 17. CONT.. The last multiplier is used as a divider. The Vg voltage is employed for adjusting thescaling factor, kdiv , of the divider. Input signal, Vin(t ), is sent to two paths. One is fed to the differentiator and then sent to theRMS-DC converter I.
  18. 18. CONT.. Other is fed to the RMS-DC converter II. Next, those outputs are sent to the divider tomanipulate a DC voltage that represents thefrequency of sinusoidal input signal as the outputof the FVC.
  19. 19. ADVANTAGE- A multi-GHz frequency-to-voltage converter isdesigned and implemented with this module. Input power calibration is possible in proposedmodel..
  20. 20. DISADVANTAGE- Less accurate. Non-linear due to integrator.
  21. 21. APPLICATION Power control. Communication. Instrumentation system. Measurement system .
  22. 22. CONCLUSION With proposed method , spikes effect are solved. Additionally the operating frequency has beenraised to 1 GHz to 4 GHz.
  23. 23. REFERENCES files/data_sheets/AD734.pdf
  24. 24. THANK YOU