A Frequency to Voltage Calculator is an electronics tool that determines the output DC voltage of a frequency-to-voltage (F-to-V) converter circuit. These specialized circuits are designed to take an input signal of a certain frequency and produce a corresponding DC voltage that is directly proportional to that frequency. The calculator uses the specific "conversion gain" of the F-to-V converter, which is its defining characteristic, to compute the output voltage for any given input frequency. This function is crucial in many industrial and automotive applications, such as in tachometers that convert an engine's rotational speed (a frequency) into a voltage to drive a display, or in sensor systems where a frequency-based signal needs to be read by a voltage-based control system.
formula of Frequency to Voltage Calculator
The formula to calculate the output voltage from an F-to-V converter is a simple linear relationship.
Output Voltage = (Conversion Gain * Input Frequency) + Offset Voltage
For most ideal or simple F-to-V converters, the offset voltage (which is the output when the input frequency is zero) is 0V. The formula then simplifies to its most common form:
Simplified Formula:
Output Voltage = Conversion Gain * Input Frequency
Where:
- Output Voltage: The resulting DC voltage, measured in Volts (V).
- Conversion Gain (k): This is the most important parameter of the specific F-to-V converter. It is the scaling factor that defines how many volts the device outputs for every 1 Hertz of input frequency. Its unit is Volts per Hertz (V/Hz). This value must be known from the device's datasheet or determined through calibration.
- Input Frequency: The frequency of the signal being measured, in Hertz (Hz).
Output Voltage for a Sample F-to-V Converter
This table illustrates the linear relationship between the input frequency and the output voltage for a hypothetical F-to-V converter with a conversion gain of 10 mV/Hz (or 0.01 V/Hz).
| Input Frequency (Hz) | Calculation (at 0.01 V/Hz) | Output Voltage (V) |
| 100 Hz | 0.01 * 100 | 0.1 V |
| 250 Hz | 0.01 * 250 | 0.25 V |
| 500 Hz | 0.01 * 500 | 0.5 V |
| 1 kHz (1,000 Hz) | 0.01 * 1000 | 1.0 V |
| 5 kHz (5,000 Hz) | 0.01 * 5000 | 5.0 V |
| 10 kHz (10,000 Hz) | 0.01 * 10000 | 10.0 V |
Example of Frequency to Voltage Calculator
An automotive engineer is designing a system that uses an F-to-V converter to measure the speed of a spinning shaft.
First, the engineer selects an F-to-V converter integrated circuit and finds its specifications in the datasheet.
- Conversion Gain (k): 0.005 V/Hz (or 5 mV/Hz).
Next, a sensor on the shaft produces a signal with a frequency that is proportional to its rotational speed. At a certain speed, the sensor outputs a signal of 800 Hz.
- Input Frequency: 800 Hz
Now, the engineer uses the formula to calculate the expected output voltage from the converter.
Output Voltage = Conversion Gain * Input Frequency
Output Voltage = 0.005 V/Hz * 800 Hz
Output Voltage = 4 V
Therefore, when the shaft's sensor is outputting an 800 Hz signal, the F-to-V converter will produce a steady DC voltage of 4 Volts.
Most Common FAQs
An F-to-V converter is an electronic circuit that takes a periodic input signal (like a square wave or a sine wave) and generates a DC output voltage whose level is directly proportional to the input signal's frequency. They are a key component in instrumentation, control systems, and communication equipment for translating frequency information into an analog voltage that can be more easily measured or used to control other circuits.
The conversion gain, sometimes called the transfer function or scaling factor, is a primary specification for any F-to-V converter chip or module. It will be clearly listed in the manufacturer's datasheet for the component. If you have built your own circuit, you would need to calibrate it by applying a known input frequency and measuring the output voltage to calculate the gain.