1. FREQUENCY TO VOLTAGE CONVERTER By Prashant singh imi2011003

2. TABLE OF CONTENT 1.Introduction. 2.Basic FVC. 3.Proposed FVC. 4.Block Diagram. 5.Hardware description. 6.Advantage. 7.Disadvantage. 8.Conclusion.

3. INTRODUCTION  Electronic devices that generate an output voltage or current proportional to the frequency of sinusoidal input signal.  It include op-amp for signal processing and RC network for removing frequency-dependent ripples.

4. BASIC FVC  This is realized by a differentiator, an integrator, a divider and a square-rooter. A 1-4 GHz Frequency-to-Voltage Converter Design Department of Electronics Engineering, National Chiao -Tung University, 1001 University Road, Hsinchu, Taiwan

5. CONT..  The division of the differentiator output to the integrator output causes large spikes when an initial value of the integrator is not zero.  Here output is proportional to input frequency without the influence of the input power.

6. PROPOSED FREQUENCY TO VOLTAGE CONVERTER  It is composed of a differentiator, two RMS-DC converters, and a divider.  Both include a frequency discrimination path and input power calibration paths.  In the frequency discrimination path, the input frequency was discriminated by an integrator or differentiator, respectively.

7. CONT…  The RMS-DC converter is used to detect the output amplitude of the integrator or differentiator.  In the input power calibration paths, which are only composed of a RMS-DC converter for input power level detection.  Finally, the current or voltage dividers are used to acquire the value of the input frequency.

8. Basic Block Diagram

9. Detailed Structure Proposed block diagram[2]

10.  Frequency discrimination path contains an integrator or differentiator and RMS-DC converter.  the input frequency is discriminated by an integrator or differentiator  Output amplitude of the integrator or differentiator is discriminated by RMS-DC converter.  Input power calibration path detects input power level.

11.  Current or voltage dividers are used to get the value of the input frequency.  Frequency discrimination converts the signal to a DC voltage V f by power detection.  Composed of an attenuator and another power detector, the input power calibration path gives a DC voltage (Vcal) as a reference to calibrate the signal amplitude

12. CONT..  The input signal is a pure sinusoidal signal with a peak amplitude of A and input frequency of ω n.

13.  The derivative of this signal at the output of the differentiator will be - where τd is the time constant of the differentiator.  Feeding Vin(t) and Vd(t) into the RMS-DC converters yields the results as-

14.  Dividing (4) by (3) we get-  where k=k div τ d is the sensitivity of the converter and k div is the scaling factor (gain) of the divider.  The output signal is linearly proportional to the input frequency, ω n, and insensitive to the input signal amplitude, A.

15. BLOCK DIGRAM CONT.. Simple and Accurate Frequency to Voltage Converter A. Lorsawatsiri1, W. Kiranon1, V. Silaruam2, W. Sangpisit1, and P. Wardkein1 1 Faculty of Engineering, King Mongkut’s Institute of Technology Ladkrabang Ladkrabang, Bangkok 10520, THAILAND

16. HARDWARE DESCRIPTION  5 operational amplifiers and 3 analog multipliers are used.  One of the op-amp is used for performing the differentiator.  The time constant of the differentiator,τ d can be set by adjusting the resistor, R1, and/or the capacitor, C1, values.  Other operational amplifiers are connected with multipliers to realize RMS-DC converters

17. CONT..  The last multiplier is used as a divider.  The Vg voltage is employed for adjusting the scaling factor, k div, of the divider.  Input signal, Vin(t ), is sent to two paths.  One is fed to the differentiator and then sent to the RMS-DC converter I.

18. CONT..  Other is fed to the RMS-DC converter II.  Next, those outputs are sent to the divider to manipulate a DC voltage that represents the frequency of sinusoidal input signal as the output of the FVC.

20. ADVANTAGE-  A multi-GHz frequency-to-voltage converter is designed and implemented with this module.  Input power calibration is possible in proposed model..

21. DISADVANTAGE-  Less accurate.  Non-linear due to integrator.

22. APPLICATION  Power control.  Communication.  Instrumentation system.  Measurement system.

23. CONCLUSION  With proposed method, spikes effect are solved.  Additionally the operating frequency has been raised to 1 GHz to 4 GHz.

24. REFERENCES  http://www.globalspec.com/learnmore/data_acquisition_signal_condi tioning/signal_converting/frequency_to_voltage_converters http://www.globalspec.com/learnmore/data_acquisition_signal_condi tioning/signal_converting/frequency_to_voltage_converters  http://www.wisegeek.com/what-is-a-frequency-to-voltage- converter.htmhttp://www.wisegeek.com/what-is-a-frequency-to-voltage- converter.htm  www.analog.com/static/imported files/data_sheets/AD734.pdf www.analog.com/static/imported

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