T T = trace thickness. Here, the via carrying the signal is placed at the center and is surrounded by 4 ground vias. When dealing with transmission lines, Characteristic impedance is a crucial parameter, probably the most crucial that you will encounter. Note that vias are made out of plated copper which typically has a resistivity of 1. Calculate trace width values based using the IPC-2221 charts by providing inputs such as current thickness and temperature values. Stripline Impedance. IPC 2141 Trace Impedance Calculator. It seems I could largely do without any impedance matching considerations, given what the trace lengths are. For your convenience, we have designed a Impedance Calculator to help you calculate the impedance and trace width you need. Things I noticed in any RF IC. Access. External traces: I = 0. The edge couple differential microstrip transmission line is a common technique for routing differential traces. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. thermal, and signal integrity aspects of traces on a PCB. Just as a sanity check, we can quickly calculate the total inductance of a trace. INPUT DATA. This page covers Microstrip Width Calculator. Trace Current Calci User Inputs: [Amps] [Degrees C] [oz. 3mm, as shown below: This increases the impedance slightly to 91. /sq. . If impedance control is necessary, determine the trace width required to reach your impedance target. as input parameters i looked up the material datasheet from my board house and got: Er 4. Therefore, the IPC-2141 equations are only accurate when attempting to calculate a trace width corresponding to a 50 Ohm single-ended. There are some advantages to using a microstrip transmission line over other alternatives. Microstrip Impedance Calculator. Just as a sanity check, we can quickly calculate the total inductance of a trace. Thank you. And that is how you can easily calculate the impedance and trace. You may use this online tool to calculate an estimate of the minimum trace width for a given current and copper weight. The Microstrip Impedance Calculator is a vital tool in the design and analysis of microwave circuits. Here is a couple of calculator links: In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. This form of microstrip is composed of two traces. 24 hours a day, 7 days a week. IPC 6012 CLASS 3/ES. Calculate the Differential Microstrip Impedance of a transmission line based on the the distance between the strips, height of the substrate, trace thickness and dielectric constant of the substrate. Designing trace width for HDI impedance adjustments. Calculate Minimum Trace Width. the current table. For differential pairs, there is also a spacing value given. ). 44 x A0. 2 Stripline Impedance A circuit trace routed on an inside layer of the PCB with two low-voltage refere nce planes (such as, power and / or GND) constitutes a stripline layout. For example, if you wish to input "25000000", just type "25M" instead. Factors Affecting Coplanar Waveguide Impedance When calculating coplanar waveguide impedance, there are many factors that affect the waveguide’s impedance, losses, and. via stitching to GND plane. The physical parameters of the trace i. Altium Designer’s impedance calculator takes your board layer stackup information and sends the trace width and thickness results to your design rules. Reference: R. Step 1 Calculate singled ended impedance for each: Use "impedance + trace space" from top drop down box: Set Z=50R, click single ened, gives a result of. To use it, first select the tolerance of the resistor: 10%, 5% or equal or smaller than 2%. 98H / (. Calculate the effective dielectric constant. 1 ohms; In addition to those calculation I found some other resources with some sample trace properties: Mikrocontroller. Impedance control: Here, the impedance is controlled through the dielectric thickness, the trace width, and space. All transmission lines are 1 ounce thick (1. For this example, we will use 2. This calculator finds both odd and even transmission line impedance. 0mm Outer Copper Weight. 08mm, my trace width should be 0. 414 times higher than the actual trace width. The shortcomings of crosshatch or mesh as a high frequency return path. 44, c =. 725. 2mil is the calculation trace width(the adjusted trace width,need to adjust trace width to meet impedance)Access Rogers' calculators, literature, technical papers and request samples on your smart phone or tablet through the ROG mobile app. It is possible to select other units. 048 x dT0. For a rough estimate, it might be in the range of 10 to 20 mils (0. This tool uses formulas from IPC-2221 to calculate the width of a copper printed circuit board conductor or "trace" required to carry a given current while keeping the resulting increase in trace temperature below a specified limit. where Z 0,surf can be computed as specified in Eq. Microstrip Trace Impedance vs. There is no impedance calculator included with Pads Layout. 6k 24 24 gold badges 118 118 silver badges 183 183 bronze badges. In HDI boards, where BGAs of fine pitch are used, careful selection of trace widths and height are employed to escape the traces between pads and vias in pads. For this reason, trace width is important in the design of striplines. Equation 3. Sierra Circuits’ PCB Conductor Spacing and Voltage Calculator calculates the minimum spacing between two conductors if the potential difference between them is provided. RF IC -> Balun N/W -> PCB antenna or Chip Antenna. Once the routing is done check the trace width. We get a lot of questions about trace impedance and how to calculate the right trace size to hit a specific impedance in a manufacturable PCB. The guides says spacing under 0. Ohm’s Law provides the framework for solving network analysis problems; when the curtain gets pulled back, Ohm’s Law updates to become the relationship between voltage, current, and impedance, not resistance. t. If you use your layer stackup calculator with a thick 2 layer board to calculate the differential impedance for microstrips, you’ll find that the actual trace width needed is much smaller and is a function of spacing. Trace Impedance Calculator. In the case where there is a plane present, a correction factor is applied to determine the required copper. There are multiple tools on Internet to calculate the net width to use. Most board manufactures will have a preferred tool that PCB designers can use to calculate the Impedance but there. 9E-3 [1/°C], T TEMP is the trace temperature [°C]Calculate the required trace width for a specified current using the PCB Trace Width calculator. Menu. After changing W to 14 mil click “Analyze” and you can see Zo is now calculated to be 49 ohms. For example: Yellow Violet Red Gold: 4 7 x100 ±5% = 4700 Ohm, 5% tolerance. The characteristic impedance is given by: Eq. Trace Height (H) Figure 4. 024, b = 0. Enter the relative permitivity, width of the trace, the ground plane spacing, and the substrate thickness to calculate the characteristic impedance. The tool implements numerical solutions of Maxwell’s equations to render accurate and consistent results. These calculators give. I am designing a 4 layers PCB and under the antenna trace I have a keepout, so there is no cooper on the 2 internal layers ( L2 and L3). The required values are trace thickness, substrate heights, trace width, and subtrate dielectric in the calculator above and press the "calculate" button. 6 Band Resistor. If you are using very fast rise/fall times (regardless of frequency) and ringing is your problem, you'll need to use a trace impedance calculator, with the trace. 03) it gives me almost 160 Ohm - and even if use 53mil conductor height or. 4 mil, εr. Trace Width (W) Figure 3. 25 Ohms and is therefore out of the limit. Trace-Width Calculator (PCB Trace Power Handling Calc) Calculates trace width values based on using the IPC-2221 (A) equations. Obviously, there is no ground on the bottom side. Polar or rectangular grids only allow direct reading of S11. 0. 001 inch). Other parameters to consider. It is not always possible to adjust trace length and width, hence implementing lower copper thickness is one of the feasible ways. Trace Thickness (T) 2. Select a trace impedance profile over the length of the taper. The Dk of a PCB material largely determines the trace width of controlled impedance transmission lines on the circuit board; the greater the Dk value, the lesser the trace width will be for the same target controlled impedance value. copper trace on a 4-layer board with 8 mil thick dielectric and Dk = 4. 035mm and Er = 4. Balun's Single Ended Impedance = 50 Ω Ω. RF Attenuators. The Smith Chart achieves this by superimposing a grid on S11 that maps load impedance. Tuning the Width and Gap Settings. There are a few points to note about this. PI Network Impedance Matching. 2. (Fat!) Formulas for calculating this can be found in various. There are several formulas and online calculators that can be used to calculate trace width. Effective Antenna Aperture Calculator. The calculator then uses a formula to calculate the width and spacing of the trace or transmission line required to achieve the desired characteristic impedance. The aim of the Impedance Calculator is to support the. 7E-6 [Ω · cm] L is the trace length [cm] T is the trace thickness [cm] W is the trace width. For low power signal traces it is generally advised to keep traces small to increase the available space available for routing. 25mm, a trace width of 0. To configure the board layers and input the material widths, go to the “Design” pulldown menu and click on “Layer Stack Manager”. W W = trace width. 6mm 2. For example, a 2. W. And this is enough to initiate low-level oscillations. 208mm per stackup at here. Some numbers that work: Track width 4 thou, track separation 4 thou, depth to plane 6 thou on 1 oz copper gets you pretty close according to the Saturn PCB toolkit. Going Forward with a Trace Impedance Calculator. 024. Note: The results are only for approximation and rough estimation, the. To manufacture controlled impedance printed circuit boards, one must be able to measure impedance. The tool will display the following results in red at the bottom: Recommended signal layersPCB Trace Impedance Calculator. 5 mil (0. 5 mm, trace width W = 0. In HDI boards, where BGAs of fine pitch are used, careful selection of trace widths and height are employed to escape the traces between pads and vias in pads. A 20 mil trace will have a much greater tolerance for losing metal than a 3 mil trace would. Round up to nearest 5 mils. 6. They include conductor spacing, creepage, and insulation requirements. Talk to a Sierra Circuits PCB Expert today. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion. R. h : Trace thickness, t (input3) : Impedance, Zo (input4) : OUTPUT Microstrip Width, mils : EXAMPLE: Inputs: Relative dielectric permittivity = 3. A cross-hatch plane is shown in the image below. For example, row ‘a’ above shows details of layer 1 (100 ohms) on a differential pair with a trace width of 4. Our current online trace width calculator is useful for clients who need to calculate the minimum/maximum trace widths for. In addition to the width and thickness of the trace, the impedance is a function of the thickness of the substrate, the dielectric constant of the substrate, and the distance of the trace from the ground plane. so i opend the KiCad PCB Calculator and tried to get some values out of this. 5 mil which we can round to 14 mil. 2E-6 Ohm-cm. Reset. Click on Setup -> Constraints > Electrical Constraints Set - > Differential Pair Value - > Calculator > If you put 10 in the Line Width, the calculator calculates the single ended as well as differential impedance. The Calculator. Z0,air Z 0, a i r = characteristic impedance of air. For an embedded (internal) microstrip, the formulas provided in paragraph 4. Dielectric thickness vs. One of the most common inquiries that we encounter at Bittele electronics are regarding our standard trace widths for a given board thicknesses and copper weight. The PCB designer needs to ensure that noisy digital circuit power supplies are separated from critical analog circuit power supplies and circuits. Dielectric constant. 2 of the Microstrip Calculator, h=H1 and b=H2-H1. Voltage regulator circuit board. There are many calculators available online, as well as built into your PCB design software. This is found to be 10mm. Sierra Circuits’ Trace Width, Current Capacity and Temperature Rise Calculator is an advanced PCB tool that works based on the latest IPC-2152 standard. The IPC-2221 standard and IPC-2152 standard both include this guidance on designing for thermal reliability, and there has been some debate as to the applicability of each standard. ϵr ϵ r = substrate dielectric. I celebrated my 18th birthday playing with an oscilloscope — a gift from my grandparents. 8 with 2-oz copper. H1=> 8. This flow is outlined below. This phenomenon is equally true for PCB traces and. The Fairchild application note also says that the differential characteristic impedance of the D+ and D- lines should be 90 ohms. Vias (plated holes) are used to route electrical signals among different layers of a multilayer. I would like to calculate the trace width of a dipole PCB antenna in order to match a 50ohm impedance. To calculate PCB trace resistance, The 50 ohm PCB trace calculator is designed considering the following formula. 68. Pasternack PCB Microstrip Calculator is an online calculation tool that lets you compute a microstrip's height/width ratio, impedance and relative dielectric constant for a microstrip transmission line. This calculator assumes the distance between the two reference planes to be an equal distance. 024 x dTI = 0. The subsequent dialog that appears - the Impedance Formula Editor dialog - contains impedance calculators for both Microstrip and Stripline impedance. 8 * W + T)]) ohms. Inputs: Optional Inputs: Results for Internal Layers: Results for External Layers in Air: Notes: The trace width is calculated as follows: First, the Area is calculated: See full list on protoexpress. 78 mil. The PCB trace impedance increases as the width decreases. 0. 25 Dimensional units: mm milsA uniform transmission line on a PCB has a definite trace width and height, and is at a uniform distance from the return path conductor - which is usually a plane at a certain distance from the. The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a calculated impedance according to the IPC-2141 standard. PCB Trace Width Calculator. When designing differential pairs and determining their impedance, it’s important to understand how coupling will affect the pair. per sq. Trace Spacing Calci 3. Microstrip Impedance Calculator. Contents. To use this tool, enter the values for trace thickness, substrate height, trace width, trace spacing, and dielectric constant in the calculator above and press the "calculate" button. We get a lot of questions about trace impedance and how to calculate the right trace size to hit a specific impedance in a manufacturable PCB. You can find trace impedance calculators online or in your CAD software. 6 ohms. Some of its key features include:. net Forum. PCBWay is a professional quick-turn PCB prototyping, PCB Assembly and low-volume production manufacturer located in Shenzhen China. to select appropriate isolation materials, layer thickness, trace width, distance between traces,. Place critical components, such as microcontrollers or high-speed ICs, close to the power source to avoid trace stubs. This is more than the to times trace width which is recommended (also read as close as possibly). Uncoated microstrip single-ended impedance calculator. 3mm of the microcontroller), therefore i rounded the width to 0. Off the top of my head, I can think of Polar and z-calc but I never liked these. Figure 2. com PCB Trace Impedance Calculator. Verify Against Other Design Rules. It displays the impedance of the input and output match in a 50-ohm test environment as measured on a network analyzer. 4 , h = 4. Below is the schematic Below is my layout. Impedance calculators or formulas like the one mentioned earlier can help determine the required trace width. Typ e, V ref and, if needed, I a d j , select the field you want to calculate (one of the resistors or the output voltage) and enter the other two values. 2. The Impedance Formula Editor dialog. T-Match Topology. Dielectric thickness. PCB Trace Width Calculator. 0mm1. . You can reduce this effect by implementing coaxial via structure. The Smith Chart graphically maps S11=reflection coefficient= (ZL-Z0)/ (ZL+Z0) to Load Impedance (ZL), normalized to Z0 (source impedance = center of chart). Maintain consistent trace widths to ensure controlled impedance. You can use our trace width calculator to design the right traces for your boards. Aside from impedance and annular ring calculations, one of the other major formulas specified in this standard relates temperature rise, trace width, and trace current. When I was 12 years old, I opened a television for the first time, and that was when my passion for electronics started. Just enter the given values for trace thickness, substrate heights, trace width and substrate dielectric in the calculator above and press the "calculate" button. Even Mode Impedance (Zeven) Ω . 92445. The trace width can then be calculated by re-arranging this formula to determine the cross-sectional area that. This tool includes an industry-standard field solver that is built into your PCB layer stackup. Knowing that the test cable and the test output are 50 ohms, it is possible to use Equation 3 to calculate the impedance of the trace under test. A pair of lines can be modeled as follows: Differential pair line. Note: Units do not matter for this calculation as long as they are consistent. The rigid-flex fab notes must consist of rigid notes and flex notes. Modeling approximation can be used to understand the impedance of. Calculate inductance, capacitance, and achieve impedance matching using L-match. Note: The trace on the inner layer need to be much wider than the trace on the outer. Geometric Parameter Definitions: W: trace width: T: trace thickness: H (/H1) height of trace or dielectric above return plane: C: distance between the differential stripline pair: er. g. It displays the impedance of the input and output match in a 50Ω test environment as measured on a network analyzer. 1 Answer. The impedance of a trace is calculated based on the placement of plane and signal layers in the PCB stackup. Cite. Use an impedance calculator to determine the trace width (W) and spacing (S) required for the specific board stack-up being used. Calculations are made using the formula below: Where: Enter the frequency and inductance into the calculator, choose the. 4 ohms; differential impedance: 90. Use the following equation to calculate the impedance of a stripline trace layout. If you reduce this trace width to 19 mils, the characteristic impedance will result in about 52. 0. EEWeb provides a suite of Microstrip Impedance Calculators as follows: Microstrip Impedance Calculator; Embedded Microstrip Impedance. Simply enter your required temperature rise limits and operating current (RMS). This Javascript web calculator calculates the resistance, voltage drop, and power loss of printed circuit board vias. Determining trace impedance and propagation delay in PCB traces takes a trace length calculator and impedance profiler tool, and these features work best when they are integrated into your PCB design software. In my layer stack manager, I have the following: Note that Altium calculates that the trace. By inputting the trace width, substrate height, dielectric constant, and substrate thickness, engineers can obtain the characteristic impedance and effective dielectric constant of a microstrip transmission line. Sierra Circuits can: Help you with your controlled impedance stack-up. By understanding the microstrip transmission line, designers can. The application will often drive the trace widths and types in a PCB design and at a certain point, there is. The PCB Impedance Calculator in Altium Designer. A higher current requires thicker traces while a thicker. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. BGA3. What is the width of a trace for 100 ohm impedance? The width of a trace for a 100-ohm impedance depends on the PCB material and other factors. In addition to the width and thickness of the trace, the impedance is a function of the thickness of the substrate, the dielectric constant of the substrate, and the distance of the trace from the ground plane. While the manufacturer uses Si9000, the result does not match with what the other tools get. View All Tools. F-A t t enua t o rs. Trace width is one of the most influential elements affecting characteristic impedance and Figure 4 below demonstrates the relationship between characteristic impedance and trace width. Cu thickness. 0 and (t/h) less than 0. Single Ended Impedance Ω. Enter the same substrate parameters and 14 mil for W. I don't use less than 4 thou track widths due to the fact that a minor etching issue can introduce errors that are a large percentage of the track width. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion, copper roughness, phase shift, etc. Apr 7, 2008. The impedance of a trace is decided by its width and height from a reference plane. The Smith Chart achieves this by superimposing a grid on S11 that maps load impedance. spacing: 0,15mm. With PCBWay impedance calculator, you can calculate the approximate impedance of your PCB / high frequency circuit board. What is the width of a trace for 100 ohm impedance? The width of a PCB trace for a specific impedance depends on factors like dielectric material and thickness. 7563 mm (~30 mils). 7E-6 to 2. Electrical Spacing. Sierra Circuits follow this. Where: Z0 Z 0 = characteristic impedance of the asymmetric stripline in ohms (Ω). As a quick rule of thumb for 50 ohms, you want the ratio of the trace width to the height above the ground plane (probably your board thickness) to be around 1. Let's say I want to use L7 - GND. An obvious solution would be to have my reference plane further away from the top layer. Does trace length affect impedance? Yes, trace length can affect impedance,. 906mil. 98H / (. I would like to calculate the trace width of a dipole PCB antenna in order to match a 50ohm impedance. The general rule is separation distance should be equal to 3 times the trace width. The PCB internal/external trace resistance shall be calculated according to the following formula: R = (ρ * L / (T * W)) * (1 + α * (TAMB – 25 °C)) Where: R is the trace resistance [Ω] ρ is the resistivity parameter, whose value for copper is 1. The other option is to use a calculator based on either IPC-2152 or IPC-2221 standards. H 2 H 2 = subtrate height 2. The dialog is accessed from the PCB Editor by clicking the Impedance Calculation button in the Layer Stack Manager dialog. PCB Via Calculator. W W is the PCB trace width, in thousands of an inch (mil); A. W: Width of the microstrip trace. 0 ()' 0 0 K k K k. Calculating the Impedance. layout impedance. Qorvo Calculators and Design Tools MatchCalc Qorvo MatchCalc is a free downloadable RF/microwave matching calculator with ideal tunable passive components. Rise time-Max length Calci 2. You’ll have to input the following parameters and click on Calculate to view the results: PCB width; PCB length; Total number of component pins; Wiring channel width; Via pad diameter; Trace/space. Factors Affecting Coplanar Waveguide Impedance When calculating coplanar waveguide impedance, there are many factors that affect the waveguide’s impedance, losses, and isolation:This calculator is designed to calculate the characteristic impedance of a symmetric stripline - a flat conductor between two ground planes whose distance between the conductor and the planes is the same for both reference planes. 1. 8 substrates. This calculator determines the impedance of a symmetric differential stripline pair. See below for the definition of these impedances. The trace width is calculated as follows: First, the Area is calculated:. Generally, the wagon wheel spokes do not have to be anywhere near as wide as long traces. This tool includes an industry-standard field solver that is built into your PCB layer stackup. To use this tool, enter the values for trace thickness, substrate height, trace width, trace spacing, and dielectric constant in the calculator above and press the "calculate" button. Calculations are based on formulae from IPC-2221. comments closed; Find PCB Trace Width Based on Power April 20, 2006. But if you route a pair of traces with close coupling, the odd-mode impedance is less than the SE impedance for the same trace width (unless you adjust the line width). It is not uncommon that the calculated trace width will be a value that cannot be ordered, for. With the RF Attenuator utility you can calculate the values of the resistors needed for different types ofColor-Code. This Javascript web calculator calculates the trace width for printed circuit board conductors for a given current using formulas from IPC-2221 (formerly IPC-D-275). Board Classes. 29 mm width traces to obtain 100 Ohms ZDiff while using 0. The velocity factor is simply: 1 / sqrt (e_r*mu_r). 1 to 2. trace width:. com Blog » PCB Trace Width Calculator - March 21, 2006 […] PCB Trace Width Calculator January 31, 2006 This Javascript web calculator calculates the trace width for printed circuit boards based on a curve fit to IPC-D-275. Such a stripline is constructed with two traces referenced to the same reference planes above and below the traces with a dielectric material between them. This online microstrip impedance calculator calculates the characteristic impedance of the microstrip (Ω), W/H ratio, and effective dielectric constant (εe) by entering the value of dielectric material relative permittivity (εr),. That brings us to the Omni RF unit converter, a tool that will let you convert from and between any of the standard RF units. You can also calculate the accurate drill diameter, via to via spacing, and the thermal vias that. To use this tool, enter the values for trace thickness, substrate height, trace width. For example, when a trace bends at an angle of 90 degrees, trace width changes significantly. PCB Via Calculator March 12, 2006. I've used 7 mil trace width with 5 mil spacing, top and bottom layers (35um copper) are 0. Follow edited Oct 20, 2010 at 20:24. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board thickness, copper weight, layer,. Twisted-Pair Impedance Calculator; Stripline Trace Width Calculator;. The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a calculated impedance according to the IPC-2141 standard. This calculator not only provides the number of recommended signal layers but also assists you with PCB area, number of nets, and net density. The wider a trace is, the easier it is to fabricate. Microstrip Trace Impedance Calculator The calculator utilizes the formula for calculating the impedance of a microstrip trace: Impedance (Z) = [87 / √(ε + 1. β1 = 0. 74mm. The trace width can then be adjusted. 1. The tool implements numerical solutions of Maxwell’s equations to render accurate and consistent results. I used some online calculator to calculate parameters of trace so it has 50 Ohm impedance. The best high-speed performances are usually accomplished if the width of the component is close to the track width. T is the trace thickness [oz/ft 2], W is the trace width [mils], R is the resistance [Ω], ρ is the resistivity parameter, whose value for copper is 1. Impedance Calculation. 0 High-speed data lines. For the antenna conection I should calculate the width to fit 50 ohm right? I tried to calculate the impedance, but I am getting a large width for antenna track (1. This calculator determines the impedance of a symmetric differential stripline pair. This is. Once the required impedance and trace geometry are determined, the next step is to calculate the trace width. Impedance control with BGA escape. 3 mils in the Substrate 1 Height text box, re-enter 75Ohms in the Impedance text box and click the Upper Trace Width Calculate button W2, the upper trace width resolves to 5. Group components of specific applications together to reduce the loop areas. Column by Maurizio Di Paolo Emilio, EEWeb Editor. 41)] * ln [5. UL Certification - Flex & Rigid Flex PCBs. As an example with 1 A. trace width and thickness, distance from other copper features, dielectric constant, and dielectric thickness or distance to reference plane of the board material all contribute to the impedance of a. No ground plane under Antenna. Color Code. Now with the values shown above for the characteristic impedance and the trace width/spacing pairs, we can determine the spacing that causes the trace width for a 50 Ohm odd-mode impedance to also produce a 50 Ohm characteristic. Spacing with copper weightSierra Circuits’ Via Impedance Calculator uses the physical dimensions of a via to calculate its capacitance, inductance, and impedance. 0 ohms; even impedance: 38. 44, c = 0. Maintain consistent trace widths to ensure controlled impedance. PCB Trace Impedance Calculator. Most of the microstrip impedance calculators you’ll find online use a similar process: enter your microstrip geometry and Dk value for your PCB substrate materials, and the tool will return the impedance for your. Via Current Calci 1. 062. H (Dielectric thickness) : This means that the actual trace width for a 50 ohm line could vary from design to design. Then, using a standard PCB trace impedance calculator or using the formulas in a textbook, you’ll find that the required trace width is 13 mils. A coplanar waveguide with groundplane distance H = 1. The edge couple differential microstrip transmission line is a common technique for routing differential traces.