This document describes a frequency to voltage converter (FVC). It begins with an introduction to FVCs, which generate an output voltage proportional to the input signal's frequency. It then describes the basic FVC design using a differentiator, integrator, divider and square rooter. The document proposes an improved FVC using a differentiator, two RMS-DC converters and a divider to avoid spikes and calibrate for input power. It provides block diagrams and descriptions of the hardware and advantages/disadvantages of increased accuracy and operating frequency range but also potential non-linearity.

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 Vf 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 ωn.

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=kdiv τd is the sensitivity of the converter
and kdiv is the scaling factor (gain) of the divider.
 The output signal is linearly proportional to the
input frequency, ωn , 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,τd 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, kdiv , 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.wisegeek.com/what-is-a-frequency-to-voltage-
converter.htm
 www.analog.com/static/imported files/data_sheets/AD734.pdf

25. THANK YOU