Pi filter calculator

Pi filter calculator. Enter values for R1 and R2 to calculate attenuator loss and impedance. Enter the passband ripple, Frequency cutoff and system impedance. The following formula is used to calculate the cutoff frequencies of a bandpass filter. Enter value, select unit and click on calculate. F = 1/(2*PI()*SQRT(L*C)) Characteristic Impedance. Nov 5, 2022 · With our high-pass filter calculator, you can design a filter that only lets high-frequency signals through while cutting off low-frequency ones. Pi LPF calculator. 5. I have the following requirements to the PSU: It needs to operate with an input voltage from 100Vrms up to 310Vrms. com. Left ('string', 3) LE. 8 uH, which passes lows. C10 diverts highs. pi-arrows-h. It can be very difficult to calculate EMI filter values, since EMI is more dependent on the circuit's physical layout than the topology itself. Jul 18, 2021 · Pi filters can be designed as either low pass or high pass filters, depending on the components used. This calculator will help you determine the correct values for the inductor and capacitor in a Pi match impedance matching Jun 5, 2023 · Select "Unequal impedances" in the "Circuit type" box. The discrete equation of the low pass filter is: v O U T [ k] = α v I N [ k] + ( 1 − α) v O U T [ k − 1] The following calculators are designed to aid in the design and understanding of low pass filters. These components include two resistors and a capacitor, forming a low-pass filter configuration. RC Low-Pass Filter - 3 Button. f f f – Characteristic frequency (Hertz). Let Q be 10 and the operating frequency be 315 MHz. LE (5, 10) LT. 50 ohms and this type of filter design is for filtering RF signals that require impedance matching. It is assumed that the idle Q-factor of C1 and C2 is much higher than that of the L. So: Aug 20, 2015 · Pi filters present very-low impedances at high frequencies at both ends due to the capacitive shunting. It is called a ‘pi-filter’ because the shape of the circuit resembles the shape of the Greek letter pi (π). Enter your values: Cutoff Frequency: Impedance Z0: Frequency Response Ripple: db. Calculate the required attenuation. As an LC filter, the two components are connected either in series or in parallel. Cutoff Frequency, MHz (input1) : Characteristic Impedance, Ohm (input2) : Inductance (L) in Henries (Output1): Capacitance (C) in farads (Output2): Example : INPUTS : Fc =900 MHz, Z0 = 50 Ohm. The voltage across the C1 can be expected as a similar waveform of the capacitor filter. Calculate filter capacitance Cf. Provide the capacitance of the capacitor in a unit of your choice. A PI filter is a filter that has a series element and two parallel elements connected in the shape of the Greek letter PI. pi-prime. A passive filter (also known as a lumped element filter) is used to attenuate a signal above or below a determined frequency. e. 10% is +/-10%. Next, determine the capacitance. It is characterized in that the frequency response curve in the passband is as flat as possible, without undulations, and gradually decreases to zero in the blocking band. The equations to calculate C1, L2 and C3 are derived by Horowitz and Hill in [1]. It is possible to have up to 9 stages of LC pair for this calculator. Select filter inductance Lf. Finally, verify the selected LC components with multiple speaker Oct 3, 2017 · These are the formulas : L = Zo / (2pi x Fc) Henries. Design Example: Suppose you have R=100 and a desired cutoff of fc=1e6. Alternatively, Generate R1 and R2 for a wanted attenuation. Set the attenuation to 40 dB in the second box of the calculator. The resulting common mode filter configuration would be as follows: These filters are most effective between 50 kHz and 500 mHz. Z0 refers to the characteristic impedance of the system i. So: 2Pi x F x L = 1 / (2Pi x F x C) And: 2Pi x F x L x 2Pi x F x C = 1. Select from 4 different filter types based on Class-D output, switching topology and performance. After finding the constraints of the pi network, designers need to calculate the equivalent impedance to match the source. Here, Zo is the characteristic impedance of pi type symmetrical attenuator, which is equal to the value of source (Zs) and load impedance (ZL). scswift June 26, 2014, 8:42am 3. You may also request new icons at the issue tracker. The choke and the capacitors are connected in series between two points (input and output). Jun 19, 2022 · C = I / (2 x f x Vpp) (considering f = 50Hz and load current condition as 2amp) = 2 / (2 x 50 x 1) = 2 / 100. When one is on, the other off. For this simple calculator, enter in the freqency, voltage ranges and current ranges and the duty cycle, inductor and current requirements will be displayed! Frequency. Calculate Vm Vrms Vdc values of a full wave and half wave rectifiers, Vm - Maximum Voltage VDC - Average Voltage V RMS - RMS Voltage. Input corner frequency and quality (Q) factor to fine tune the audio frequency response. JFET Input Op Amps. The Pi attenuator (Pi pad) is a Enter value, select unit and click on calculate. 02 Farads or 20,000uF (1Farad = 1000000 uF) Accordingly, the above formula exposes just how the demanded filter capacitor could possibly be estimated with regards to the load current and the smallest permissible ripple current in The twin T notch filter calculator calculates the values of the resistors and capacitors needed to obtain a notch frequency as entered in by the user. 8. High Output Current Op Amps ≥ 100mA. lowpass. Pi HPF calculator. Z = SQRT(L/C) Web Calculator Power Supply Pi Filter Calculator (unequal source and load impedance) The source and load impedance can sometimes be unequal and a Pi filter can be used in this situation as well. Following is a simple LC based Pi filter calculator used for high pass filtering. The circuit got its name because the inductor and the capacitor form a Pi symbol (see schematic below). One of these areas relating to EMC in PCB design is the use of ferrite beads. 8 Ω. = 0. They are used with communication devices to retrieve the original signal after modulation. 113,236. Enter any two of parameters R, C or fc. The Pi filter is a type of electronic filter that is commonly used in power systems and electronics. Jan 2, 2024 · For comparison purposes, a pi filter is effectively two L filters back-to-back but simplifies the two series components in the middle to a single entity. Below 50 kHz active filters are usually more cost effective and above 500 mHz strip lines are generally used. It is an alternative to the very popular Pi filter. The pi filter gives steadier and smoother DC compared to other filters. 500 mA. Cut-Off Frequency. Calculates Butterworth response analog filters up to the 9th order. PI Attenuator Calculator. So, if for example, a user enters a notch frequency of 4KHz, 4KHz is greatly attenuated by the circuit. In the ZL box, type 50 Ω. Of the same system, measure the capacitance in microfarads. Inductor sources: CoilCraft DigiKey Wind your own: Inductor Calculator for hams DIY Audio inductor calculator Multilayer air core inductor calculator Inductor calculator for Jul 17, 2023 · Retrieves the last value of a specified attribute within a range. A set of 4 calculators with Butterworth response filters for analog low-pass, high-pass, band-stop and band-pass Nov 5, 2014 · Input Differential Conducted EMI Filter Design. The tool will instantly calculate the LC filter's cutoff frequency. Sample calculation. Oct 8, 2020 · A pi filter is a shunt capacitor filter followed by an LC filter which is arranged like the Greek letter π, hence it is called a pi filter. 9 Ω, R₂ = 3,062 Ω, and R₃ = 50. Then from the transfer function I'm able to find the cutoff The Pi match impedance matching circuit is used to match the impedance between two points, usually a source and a load. Enter Components The value of inductance required of the choke is simply the load in Ohms divided by the radian frequency at and above which the signal is to be attenuated. A '1% resistor' usually means +/-1% tolerance. LCF = 1/2*pi*R2*C2 LCF = 1/2 ∗ pi ∗ R2 ∗ C 2. Aug 30, 2022 · A simple RL circuit (a circuit with a resistor and an inductor) shown below can achieve this function. Feb 12, 2020 · That's correct, because you are looking in the wrong place for what you perceive to be the right solution. Enter resonant load impedance (RL) in ohm: Enter antenna impedance (RA) in ohm: Enter desired loaded Q: Enter frequency in MHz: The C1 capacitor in nF is: The C2 capacitor in nF is: This page is the index of web calculator that design and analysis analog filters. 4. Mar 17, 2022 · The pi filter is a simple, yet powerful LC filter circuit. HCF = 1/2*pi*R1*C1 H CF = 1/2 ∗ pi ∗ R1 ∗ C 1. Butterworth filter are characterized by a constant gain Dec 4, 2019 · The construction and the component values of the Pi filter calculation can be derived from the below equation to design a Pi Filter for your application. Sep 21, 2023 · This is the impedance matching calculator - a great tool that helps you solve problems with matching electronic elements within a circuit. This passive RL high pass filter calculator calculates the cutoff frequency point of the high pass filter, based on the values of the resistor, R, and inductor, L, of the circuit, according to the formula fc= R/ (2πL) . After a click on 'Calculate' the components required for the filter response are calculated. How do i calculate pi filter or what is the best values for pi filter in this design ? First explain why you need a pi filter and where it goes in the schematic. The calculator below allows you to use Pi to calculate other equations. 2. Enter the Load Impedance in Ohms and the Cut-off frequency Fc. Simply click the π symbol on the calculator then the calculation you want to carry out. 3. These videos will cover switching power supply design considerations. Last ('tag1', '-1d', '*') Left. This calculator is an active inverting bandpass filter calculator. To use this calculator, all a user must do is enter in any 2 values, and the calculator will A PI filter is a filter that has a series element and two parallel elements connected in the shape of the Greek letter PI. Butterworth Pi LC Low Pass Filter Calculator. The pi filter is a type of passive inductor-capacitor (LC) filter that features its components in a ‘pi’ shaped configuration. Finally, determine the cutoff frequency. Thermal Design Concepts: Intro to various factors that impact thermal RC Low Pass Filter Calculator. The response of the filter is displayed on graphs, showing Bode diagram, Nyquist diagram, Impulse response and Step response. 99 mH (50/(2π x 4000)) inductor. This series includes:Thermal Design Guidelines and Recommendations: Strategies and recommendations for maximizing the thermal performance of your designs. PT4115 feeds LEDs. The cutoff frequency formula for an RL circuit is given by: f_c = \frac {R} {2 \pi L} f c = 2πLR. Once you have determined the desired cutoff frequency, you will need to input this value into the Chebyshev pi low-pass filter calculator. 3) Low pass filter resistor selection calculator. The parasitic elements related to component spacing, shielding, pickup, coupling, etc. The LC filter, also called the LC filtering element, designates a circuit with an inductance L and a capacitance C in electrical engineering. A filter circuit is a device that is used to remove the A. Low Input Bias Current Op Amps (≤100 pA) Low Noise Op Amps (≤ 10nV/√Hz) Low Power Op Amps (≤ 1mA/amp) Precision Op Amps (Vos ≤1mV & TCVos ≤2uV/C) Jul 6, 2017 · EMI and EMC can be a tricky subjects, and it's often tempting to mis-apply design guidelines to try and reduce EMI. C C — The circuit capacitance. 42477796077. In practice, the capacitor on the chip side should be placed as close to the chip supply ball as possible. Since it is not shown, 50 ohms is the value it seems to be the custom to assume. An inductor L L acts the opposite way a capacitor does: An inductor becomes a short-circuit for low-frequency signals and an open circuit for high frequencies. The low-pass filter used for power supply filtering is formed from an inductor in series between the input and output with two capacitors, one across the input and the other across the output. A web calculator is provided so you can compute the cut-off frequency and characteristic impedance of your own filter. The Chebyshev type filter is named in honor of Pafnuty Chebyshev because their mathematical characteristics are derived from Chebyshev polynomials. This forms a Pi filter and reduces the amount of noise to the supply considerably. Calculation of each capacitor value requires two inputs. 20 mA. Now you're done with your resistors! The values should be R₁ = 76. Radio Frequency Engineering Calculator. Another aspect of the design of the Jun 13, 2013 · The Calculator. Low Input Bias Current Op Amps (≤100 pA) Low Noise Op Amps (≤ 10nV/√Hz) Low Power Op Amps (≤ 1mA/amp) Precision Op Amps (Vos ≤1mV & TCVos ≤2uV/C) Rail-to-Rail Op Amps. The formulas used are taken from EIMAC's "Care and Feeding of Power Grid Tubes". To compute the frequency, specify the RC circuit's Design active filters with real op amps in minutes. Characteristics of Pi filter (π- filter) The Pi filter has the characteristics to generate a high output voltage at low current drains. - impedance of the filter. This calculator below requires Cutoff Frequency (Fc) Load Impedance (RL) Example T Filter Calculation For a source impedance of 50 Ω and a load Impedance of 1 kΩ, design a low pass filter with a cutoff frequency of Aug 1, 2023 · How to calculate cutoff frequency? First, determine the resistance. where: R R R – Resistance of the resistor (Ohms); C C C – Capacitance of the capacitor (Farads); and. Extracts a specified number of characters from the left side of a string. R 1 requires the low cut-off frequency F L and the capacitance of C 1. C only and an inductor allows D. Fc = 1 / (2pi x square root ( L x C) Hz. www. Often a more empirical approach is needed. The Pi (pad) RF attenuator calculator allows you to determine the Resistor values (R1 & R2) for a Pi attenuator. Calculate the cutoff frequency using the formula above. The Pi filter is designed to attenuate high-frequency noise and interference while allowing the desired signals to May 8, 2015 · Ferrite beads should be used in between two capacitors to ground. Use this utility to simulate the Transfer Function for filters at a given frequency, damping ratio ζ, Q or values of R, L and C. Usually source and load terminations are the same, but sometimes the filter is designed to work from a low source impedance into a high load impedance, to avoid the 6dB loss (half the voltage) of a normally terminated 3 days ago · RC time constant calculator. A filter circuit is in general a combination of inductor (L) and Capacitor (C) called an LC filter circuit. Load current is 200-215mA and switching frequency is 500kHZ. Where LCF is the lower cutoff frequency (hz) HCG is the high cutoff frequency (hz) R1 and R2 are the resitances in a passive The cutoff frequency is the frequency at which the filter will transition from allowing signals to pass through to blocking them. Pi Scientific Calculator. Resistance in this calculator formula for pi attenuator is measured in Ohms. Figure 2: Low-pass Pi filters (left) can tap into an RF-transmission path allowing just the lower frequencies to pass. The band stop filter capacitor calculator can be used to calculate the values of capacitors needed to create a filter with a specific cut-off frequencies F L and F H. RC Low-Pass Filter. The main application of Pi filters in power This page contains the basic equations for an L-C filter. For microcontrollers its often the CPU clock / 256. Determine the impedance for Vishay surface-mount ferrite beads at any given frequency, and calculate the effective impedance at the stated frequency with DC bias applied. . Dec 6, 2021 · We are getting ripple at the output in the range of 10 mV to 12 mV, so we are thinking to add a pi (C-L-L) filter at the output of the DC-DC converter. I am designing a single phase MIL-STD-461 AC/DC PSU. Then hit the button of the desired parameter. Capacitors and Resistors are both limited to a 'typical' range; 10pF to <10000uF for caps, 1Ω to <100MΩ for resistors. The Butterworth type filter was first described by the British engineer Stephen Butterworth. Increasing the loaded Q-factor of the Pi-circuit Qp, increases harmonic Select a filter type to begin your design. Vin(s)→ Chebyshev Lowpass Filter Designer. Jan 18, 2024 · To calculate the resonant frequency of a circuit composed of an inductor and a capacitor, follow these steps: Write down the capacitance C in farads. Jul 30, 2019 · This calculator is designed to calculate a real Pi-matching circuit of the tube power amplifier of the transmitter or the PI-filter in another words. Apr 24, 2020 · In general, the PI filter at higher Q can be regarded, ignoring impedance matching as a parallel resonant circuit made from a coil L and a capacitor C with a capacitance equal to: C=(C1*C2)/(C1+C2) This resonant circuit should resonate at the frequency the filter will be used. C = 1 / (Zo x 2pi x Fc) Farads. The Pi Network LPF (Linear Prediction Filter) online calculator is a powerful and user-friendly tool that allows users to accurately compute the LPF value for a given input signal. The notch frequency is the frequency that is most greatly attenuated by the circuit. Calculate damping capacitance Cd. will outnumber the amount of actual parts. Find the capacitance needed by entering the two parameters above and hit "Get C". However, convention and some literature quote return loss as a negative value akin to an S (1,1) measurement on a Network A passive filter (also known as a lumped element filter) is used to attenuate a signal above or below a determined frequency. Min Vin. The output is the inverted input signal, which means the input signal and output signal are 180 degrees out of phase. Our calculator allows you to create an active or a passive filter, depending on your needs. In the ZS box, type a value of 75 Ω. The Butterworth filter is a type of electronic filter. Chebyshev filters are analog or digital filters having a steeper roll-off and more passband ripple or stopband ripple than Butterworth filters. C 1 requires the low cut-off frequency F L and the resistance of R 1. To use this calculator, all a user must do is enter any values into any of the 2 fields This page is a web application that design a RLC low-pass filter. Each component in the Pi Filter performs its own role in the filtering Oct 20, 2017 · The pi circuit behaves as a second-order low-pass filter, and works exactly the same: as you increase the component size, the frequency will move closer and closer to zero. The calculator is specifically designed for use with the Pi Network, which is a mathematical algorithm used for digital signal processing applications. calculatoredge. RL High Pass Filter Calculator. The signal goes through 6. The difference between the noise level at the fundamental switching frequency and the required level defined in the appropriate standard for the target market place. The shunt capacitor C1 does the main filtering. As you can see, the peak-to-peak voltage is around 12 mV, but the frequency is not stable, varying by up to 100 kHz. 3 days ago · This LC filter calculator will be handy when designing either a low-pass or a high-pass filter: Enter the inductance of the inductor in your desired unit. For example, attenu-ation at and above 4000 Hz into a 50 load would require a 1. LC pi filter can be used with a bridge rectifier. Result will be displayed. Select the maximum ripple you would like to have in the passband. Impedance with DC Bias Current =. 2) Low pass filter capacitor selection calculator. All that is needed is to input the desired cutoff frequency, the passband, the impedance, and the ripple. General Purpose Op Amps. Calculation of each resistor value requires two inputs. Here is the current list of PrimeIcons, more icons are added periodically. LC Filter Calculator – How LC filters work. Apr 28, 2017 · The filter is designed with these terminations in mind, and if mis-terminated, it won't have the expected frequency response. T filters conversely have very-high impedances at high frequencies because of the inductive coupling (Figure 2). 0. Where: f c. Whether you have trouble with RC high-pass filter calculations or filter circuit configurations, you've come List of Icons v5. For example 3 times π = 9. However, since the filter is second-order, the 50hz frequency content will be even more attenuated at the output than with the first order low-pass at the same cut-off Passive Pi filter are passive electronic circuits that consist of three components arranged in the shape of the Greek letter Pi (π). Given R and C, calculate the cutoff (-3dB) frequency of a low-pass filter. C components to reach the load. Following is a simple LC based Pi filter calculator used for low pass filtering. The time equation of the low pass filter is: v U T ( t) = v I N ( t) R ⋅ d v O U T d t. This passive RC low pass filter calculator calculates the cutoff frequency point of the low pass filter, based on the values of the resistor, R, and the capacitor, C, of the circuit, according to the formula fc= 1/ (2πRC) . For example with a RC low pass filter I just use the voltage divider formula and from that, using the impedances, I find the transfer function of the filter. Write down the inductance L in henries. highpass The band pass filter resistor calculator can be used to calculate the values of resistors needed to create a filter with a specific cut-off frequencies F L and F H. A simple RL circuit that functions as a high-pass filter. A capacitor allows A. Butterworth filter are characterized by a constant gain (flat response) across the midband of the circuit and a 20 dB per decade roll-off rate for each pole contained in the circuit. Aug 27, 2012 · 4. Number of Components: (1-11) Results: Inductance: Capacitance: Unit : L1: C1: L2: C2: L3: C3: L4: C4: L5: C5: C6: Web. Creates series of calculations that can be printed, bookmarked, shared and modified in batch mode. The right solution is not a Pi filter; it's a low pass filter using L, C and R. C components of the rectified output but allows the D. R 2 requires the high cut-off frequency F H and the This calculator helps determine the correct values of the inductance (L) and capacitance (C) of an inductor and capacitor to be used in a Butterworth LC bandpass filter. You can get an idea how the filter will behave, by figuring the rolloff frequencies for the various components. Pi Filter. High Speed Op Amps (Bandwidth ≥ 50MHz) High Voltage Op Amps ≥12V. Hz. This active bandpass filter is composed first of a high-pass filter which is made up of resistor R1 and capacitor C1. Dec 30, 2021 · Use or application of LC circuit : LC Pi filter is an efficient DC filter as it can filter out AC ripples easily, so LC pi filter is used designs such as AC to DC converter, frequency converter, etc. Here’s how to analyze these filters in your next design and some important simulation tips. C only to pass. RC Filters. This can be built into a FLEXI-BOX and a transmission line (50 Ohm track) PCB is available which easily adapts for this circuit with one simple trimming Equations describing a low pass filter. For a pi low-pass filter, the formula is: L = 1/(2*pi*fc*c1*c2*r) C1 = c2 = c Where: L = inductance in henries C1 and c2 = capacitance in farads R = resistance in ohms Using a butterworth pi low-pass filter calculator Calculating a Butterworth pi low-pass filter can be time-consuming, especially if you are designing a filter with a large number In the case of L-section filter, one inductor and capacitor were present so if some AC ripples say 1% is left after filtering that can be removed in Pi-filter. Schematic. This calculator works this way. *Strictly, a loss quantity when expressed in dB should be positive. The ferrite bead placement and input capacitor placement is not as crucial. This is the boost converter frequency. You're probably reading this article on a laptop that uses a ferrite to filter out Mar 15, 2012 · Calculate the capacitances C = 1/2pfX C Assume a source or generator resistance of 10 Ω and a load resistance of 50 Ω . Chebyshev Pi LC Low Pass Filter Calculator. You need to know the input resistance. DC Bias Current Slider. Calculate the L & C values needed for Pi and T topologies. Compares two values and returns true if the first value is less than or equal to the second value. Butterworth filters are termed maximally Jun 26, 2014 · Two Pi F L equal to one over two Pi F C. pi-pound. This is a Pi tank calculator, useful for impedance transformation in valve amplifiers. pi-sort-alt-slash. Current rating of at least 3 Arms (important for choosing inductors and CM choke) I have chosen a PFC AC/DC module that works as intended. This calculator is used to calculate the value of resistor R1 & R2 of pi type symmetrical attenuator (shown below) for the required value of attenuation (in dB) and for matching impedance (Zo = Zs =ZL Ω). For a Pi filter you make the values of the capacities the same. In the article, you can find a short explanation of the concept of impedance matching and learn three basic impedance matching topologies (L-match, Pi-match, and T-match). Outside this range things will probably turn to nonsense. Ohms. Sep 16, 2019 · Here is my circuit schematic below. Matching Pi Attenuator Calculator. The filter is comprised of the inductor (L) and capacitor (C). 1-866-PASTERNACK (1-866-727-8376) US and Canada only • +1-949-261-1920 International • Email sales@pasternack. pi-arrows-v. These components are basically filters, and they do perform a useful function on power cords in many electronics. On the Bode plot of the logarithmic diagonal frequency of the amplitude Sep 22, 2016 · Calculate and design audio Class-D LC filters in minutes using the Class-D LC Filter Designer. 7. pi-chart-pie. Pi filters are commonly used as rectifier, low pass, and high pass filters. The rightmost end is labelled 'VIN'. However, convention and some literature quote return loss as a negative value akin to an S (1,1) measurement on a Network 4 Butterworth types for analog filter design. Scientific calculator online, mobile friendly. Input both parameters in the resonant frequency formula: f = 1 / (2π × √ (L × C)). The equation for the characteristic frequency f f f of the RC circuit is: \small f = \frac {1} {2\pi RC} f=2πRC1. Thus, Pi filter is considered more efficient. 2Pi^2 x F^2 x L x C = 1. The LC filter cutoff frequency is a key element of this. Your next power supply design or impedance matching network might be a pi filter. This passive filter calculator has you pick your composition (RC – Resistance/Capacitive, RL – Resistance/Inductance, or LC – Inductance/Capacitive) and enter your values to calculate the cutoff/-3dB frequency. To calculate the values of a PI filter components we need four Mar 1, 2024 · An RL high-pass filter, built with a resistor and an inductor. A T-filter is used when the input impedance is low. It is true for most capacitors. Its cutoff frequency is also very simple to calculate: f_c = \frac {R} {2\pi L} f c = 2πLR. The transfer function of the low pass filter is: H ( s) = R C ⋅ s + 1. It is composed of two capacitors (labeled as C) and a choke (labeled as L). Measure the resistance in ohms of the low pass filter system. On the Bode plot of the logarithmic diagonal frequency of the amplitude Dec 2, 2021 · How to design an EMI Filter for AC/DC PSU. Calculates the resistor values, attenuation, minimum attenuation, 'impedance', reflection coefficient, VSWR and return loss of a matching Pi attenuator. In Mar 20, 2024 · Bandpass Filter Formula. There are three calculators on this page: 1) Low pass filter cut-off frequency calculator. Cut off frequency(fc) = 1/ᴫ(LC)1/2 Value of the Capacitance is (C) = 1/Z0ᴫfc Value of the inductance (L1) = Z0/ᴫfc Where, the Z0 is the impedance characteristic in ohms and fc is the cut A passive filter (also known as a lumped element filter) is used to attenuate a signal above or below a determined frequency. ht bw xh ha gq oz co mp ta jp