What is a Frequency-to-Digital Converter?
A Frequency-to-Digital Converter (FDC) or Frequency-to-Code Converter (FCC) is an electronic device that converts an input frequency of electrical signal to a digital number (binary code) that represents frequency’s quantity. They are used mainly to convert signal from sensors and transducers
What is the difference between ADC and FDC?
Analog-to-Digital Converters (ADC) use continuous physical quantity (usually voltage) as the input parameter, while Frequency-to-Digital Converters (FDC) use frequency-time parameters of electrical signals (like frequency or period) on its input. Oftenly, a rectangular wave signal with constant amplitude is used on the FDC’s input.
What are the advantages of using frequency as the informative parameter of signal ?
Frequency guarantees higher accuracy and a wide dynamic range. This delivers exceptional metrological performances at very low cost.
Additionally, frequency is immune to electromagnetic noise, so you don’t need the filters, amplifiers and DSP usually necessary in all analog and mixed-signal electronic designs. This drives to a higher level of integration, less cost and shorter time-to-market, compared to ADC based solutions.
Why is frequency immune to noise?
The very own physical properties of frequency makes it immune to electromagnetic noise, interference and distortion, so no additional influences on the informative signal are added due to interferences from noise sources like electrical engines, antennas, etc.
What means higher level of integration?
Semiconductor analog and mixed-design need extra components to filter, amplify or pre-process the analog signals before converting them into digital. That drives to bulky, more expensive design and longer time-to-market. The smaller the technological node (under 100 nm or less), the more difficult the design and implementation becomes.
The use of FDC eliminates the need of all those extra components. Being a pure digital solution you can avoid many of the hassles of mixed-signal, thus using less space and simplifying a lot the design.
Are there other FDC technologies?
Frequency benefits are known since several decades ago. Till now the bottleneck in the use of frequency as informative parameter was the long conversion time, so its use was limited to high precision measuring in non speed-critical systems. There are several classical methods for frequency measuring, and some advanced methods.
What’s the difference among modern FDC methods and Excelera method?
Excelera novel advanced method has all advantages of existing advanced methods plus: non-redundant conversion time, scalable resolution and self-adaptation.
This means two things: first, if you don’t need the highest accuracy, conversion time can be reduced. Second, you can trade off speed for accuracy or accuracy for power consumption in the same solution.
Does FDC work only with frequency output sensors
FDC gets the maximum accuracy and robustness when converting the signal from frequency (period) output sensors. However, with the use of an intermediate Voltage-to-frequency converter, any voltage output sensor (analog) signal can be converted too. Giving the possibility of connecting in the same hub all types of sensors in the market today.
Does multichanneling affect FDC accuracy?
Not, FDC makes a pure digital solution so no additional error happens when using multiplexers. This means that a single FDC can convert the signals of virtually unlimited sensors, allowing for a high level of integration.
What are typical applications for FDC?
FDC can be used in any digital smart sensors and sensor systems. And as a high performance Analog- to-digital converter, by using an intermediate Voltage-to-Digital Converter.
What are best verticals for FDC applications ?
Harsh industrial or automotive environments: Automotive, Industrial automation, Aerospace, locomotive...
Verticals with need of high metrological performance: Test and measurement, Medicine, laboratories...
Verticals that demand low-power: Internet of Things (IoT), wearables, smartphones…
Semiconductors that demand mixed-signal solutions with higher level of integration and the capacity to scale down their technology node.