Figure 4B is an end view of a stripline, with the trace between two ground planes. Copper. Tuning for your traces to the desired impedance value occurs by adjusting trace width and distance from the reference plane. High-quality circuit boards as prototype and series at reasonable prices. You will need to know the thickness of the dielectric you will be using as well as the relative permittivity (dielectric constant). The outputs impedances can be odd, even, common and differential. Dielectric Constant, Ε r: Trace Width, w in mils : Trace separation, d in mils : Trace thickness, t in mils : Dielectric thickness, h in mils : OUTPUTS Characteristic impedance in Ohms : Differential microstrip impedance in Ohms : *Note: This calculator is valid for (W/h) in range from 0. AC Termination: AC Termination of a line results in the lowest power drain, but also requires two parts. • Differential impedance is the impedance the difference signal sees • With no coupling, current into one line depends on capacitance per length of. Learn how to configure, define, and use your design’s impedance requirements for single-sided and differential on each layer, with Altium Designer’s Layer St. View All Tools. Class creation for controlled impedance routing using Altium Designer. which simplifies the process of determining the characteristic impedance of a microstrip trace. Instructions. 9 mils wide. Here is an online PCB Differential Impedance Calculator to calculate the differential impedance of Printed Circuit Board. Z0 = (60 / √εr) * ln ( (8h) / (w + s)) Where εr is the dielectric constant of the substrate material, h is the substrate height, w is the trace width, and s is the spacing between traces. traces ), and stripline traces, ( traces within the layer stack, typically sandwiched by two ground planes ). This note describes some. 0. Edit: also, think ahead if you are going to use ground pours around the traces. Speedstack Si – Insertion loss & impedance PCB stackup design including Si9000e. If you put 10 in the Line Width, the calculator calculates the single ended as well as differential impedance. 5 mil as the thickness of 3313 prepreg when the controlled impedance tracks are on top/bottom, use 5. The tool provides two networks that will have the desired impedence at that frequency. Unfortunately, TxLine doesn't do coplanar waveguide for differential traces. We recommend the software from Polar Instruments if you want to get exact impedance calculation. 48 e -0. The calculations are pretty standard and supported by many freely available calculators. Input the known values, and let the calculator determine the unknown. Note: The 6-Layer board temporarily only provides JLC3313 Stackup. Just as important as determining an appropriate trace width for a. 1. Wavelength/10 is the max trace length before you need to worry about impedance control So if you keep your traces under 15mm in length, then it doesn't matter. Wavelength calculator Calculates the wavelength of a signal using Ereff. This note describes some. The guides says spacing under 0. The idea here is to determine the spacing required for a given width with the goal of hitting a specific differential impedance value. Differential impedance refers to the inductive and capacitive impedance found between two differential traces and equals the ratio of voltage to current on the differential pair. While every trace has an impedance, we don't care about the trace reactance if the trace is only carrying DC current. . High-speed designs carry a requirement for controlled impedance, crosstalk control, and the need for interplane capacitance. Since PIe edge connector’s character impedance is 85Ω, the traces between the connector and I should be 85Ω -- the rest is usually set to 100Ω. Create a new impedance profile, then select Single-Coplanar or Differential-Coplanar from the Impedance Profile Type drop-down list. For example, a 4-mil differential trace should not have more than an 8-mil space. Single-Ended Impedance. Home;. You can use a trace impedance calculator for stripline and just make the H (height above the ground plane) very large. Mutual inductance and capacitance exist between the two traces in a differential pair. Measure all parameters S11, S12, S21, and S22. Coplanar Waveguide With Ground Characteristic Impedance Calculator. Every trace has capacitance between the trace and the return path of the signal on. Enter the differential impedance you want, the trace width, the dielectric height, the dielectric constant, and the trace thickness, and click the. Use the results from #3 to calculate the width profile with. As explained in Part 1 of this series ( Circuit Cellar 367, February 2021 [3]), PCB manufacturers can propose different PCB stack-ups, and specifying a low thickness for the so-called “top prepreg” will help to reduce the trace width. (Sorry guys, I live and I have grown up in a metric world ) With these values, Saturn PCB's off-line calculator gives 57 Ohm differential impedance. PCB Impedance and Capacitance Calculator: Microstrip Trace Impedance . KB: Route traces between flex and rigid regions. Consider some of these vital PCB routing guidelines: Keep fixed impedance traces for a particular interface or signaling protocol on the same. Broadside-coupled Asymmetric Stripline. Single ended impedance is the trace impedance with reference to ground. Use 3. FYI, I followed 2nd option and values were quite similar. 5;. 5ohms and the fact that it’s nearly flat above about 800kHz). An electrical transmission line with impedance of. You may wonder why it dips initially. Inductance – the impedance calculator uses the Impedance value to calculate the inductance per unit length. Impedance in your traces becomes a critical parameter to consider during stackup design for high-speed PCBs, but the. As seen from the formula when D decreases, while keeping B. Signal layer. It consists of a thick core (about 42 mils) and 2 prepreg layers (7 mils each). The HIGH level is brought up to a logic level (5 V, 3. 15 mm spacing. The tool implements numerical solutions of Maxwell’s equations to render accurate and consistent results. If trace width is increased for the metal losses reduction, the single end impedance will be reduces. *The structure may propagate in 3 modes: coplanar waveguide, coupled slot lines and microstrip. Every trace has series inductance. 6mm 4 layer PCB, 1oz outer copper, 0. High speed PCBs and signaling standards almost entirely use differential pairs with precise impedance. Since the op is using 1/2 oz copper this should be taken into account. Z diff = 2* Z o (1 - 0. 72e-08. differential signals should be at least five times the trace width away from other traces. The trace width required to deliver a specific. Route your single-ended and differential pair traces. 25mm trace. The two most common impedances. The differential impedance between the positive and negative trace of the transmission line is slightly less than twice the impedance of the single ended impedance. To update trace width, select the traces of interest and use the "Route > Retrace Selected" command. Doubt about 50 ohm impedance calculation. As the driving frequency increases, mutual inductance between circuits in your board will cause the impedance of your power delivery network to increase. For example, I have differential stripline signals, which should be 100 Ohm impedance. Note that the y-axis is on a logarithmic scale for clarity. Speedstack is the stackup design tool of choice for professional PCB Designers fabricators and brokers who have a requirement to document and design stackups drill plans and material requirements complete with high speed transmissionline information. There are a lot of online trace impedance calculators specifically designed for differential traces. Vias (plated holes) are used to route electrical signals among different layers of a multilayer. Copper thickness (t) = 18 micron. Regarding the impedance of USB signal traces the layout guidelines state: DP, DM Differential trace impedance = [DP(45ohm) + DM(45ohm)] = 90 ohm, and do not jump the DP DM signals that cause impedance miss match. How do cheap Raspberry CSI-2 cables get around differential impedance matching. The extracted model includes distributed parameters for resistance, capacitance, and inductance, as shown in Figure. 9D/B) Zo = Single Ended impedance. 2) S/T > 5. 4mil; Dielectric Thickness:. 6mm 4 layer PCB, 1oz outer copper, 0. This makes the problem of determining impedance much more complex, and building an initial lossless model requires a larger set of formulas. That means each trace would be a 50-ohm trace, if there were no coupling between the traces. ALGEBRAIC EQUATIONS Single Track For the stripline of Figure 2 with a symmetrically centredIf your design has controlled impedance traces, you can use our built-in impedance calculator. 3. PCB Trace Impedance Calculator. don't change the any dielectrical contant. # Impedance trace/space. differential trace impedance for USB (90 Ohms) on 2-layer FR4 board. So, let’s finish this. The tool also calculates signal losses of any given trace. D = Distance between two differential pair signals; W = Width of a trace in a. 020. Dielectric constant = 3. • Keep single-ended signals away from differential traces – distances should be at least at least 2x the trace width. In addition to characteristic impedance analysis, the signal integrity extension can perform equivalent circuit modeling of a particular trace or differential pair. These important design features are incorporated into your design rules, making impedance-controlled routing quick and easy. Hello! I'm trying to calculate the trace width for a differential pair (carrying MIPI CSI-2 signals), using JLC's impedance calculator. (5mil prepreg) But in your case if using a 10 mil dielectric; Impedance is almost constant ratiometric to the conductor geometry ratios if <2:1 ratios for planar and < 3:1 for differential coplanar. Just as important as determining an appropriate trace width for a single-ended trace is determination of an appropriate spacing between two traces in a differential pair. Signal traces of high-speed differential pairs must be routed parallel to one another with a fixed distance between them. Not all calculators will explicitly state this. A web-based tool to calculate the impedance of your PCB traces and vias. 1. If the characteristic impedance of the two single-ended lines is Z0, then Zd and Zc can easily be derived. Use the following guidelines. It is admittedly small, but it is non-zero. x. 6. Bandwidth Calculator & Max PCB Trace Length Calculator. Embedded Microstrip. When the termination resistor matches the track impedance, there will be no reflections. Before we can start routing the PCB, we need to define Design Rules for our differential traces. 3 CPW Structures; 3. For an embedded (internal) microstrip, the formulas provided in paragraph 4. The tool implements numerical solutions of Maxwell’s equations to render accurate and consistent results. 8. They will give very similar. “The Surface Microstrip. 5 mil (2116 prepreg) or 8. $egingroup$ So basically your answer shows that the JLCPCB impedance calculator results are generally in the same ballpark as the proven field simulators. The Smith Chart achieves this by superimposing a grid on S11 that maps load impedance. The surface finish is neglected. Controlled impedance traces can minimize signal reflections and thereby reduce propagation delay. Use the following guidelines. 3. Using an online calculator [4], a microstrip trace of 1oz, 120mil-wide copper on 0. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. In fab notes, give the expected impedance (100ohm differential), the acceptable tolerance (often +/-10% or 20%), and which traces are. Take note that this assumes that the distance between the conductor and the planes is not the same for both reference planes; hence the asymmetric term. A PCB impedance table will provide the trace width required to have a target impedance value on a standard stackup. Typical impedance tolerances are 10% and 7%, and can go as low as 5% or 2% in the extreme cases. 2. These calculators give us essential trace spacing and differential pair spacing if needed. 77 mm gave me a differential impedance very close to 90 Ω. Expect a large variation of manufactured PCB impedance with 0. There are many demands placed on PCB stackup design. Adjust the length matching to achieve propagation delay. The High speed protocol that is being designed for determines what the single and differential trace Impedance the traces need to meet as well as the tolerance for the impedance (e. Calculates the characteristic impedance and per-unit-length parameters of typical printed circuit board trace geometries. At some point the amplitude will stay constant. PCB Impedance and Capacitance Calculator: Asymmetric Differential Stripline. Modeling approximation can be used to understand the impedance of the edge couple differential stripline transmission line. To find what a given trace width will have a single ended or differential impedance, we can use a built in calculator from Allegro. 0. There are some advantages to using a. and thats the first time iam doing ethernet things. 2. The coaxial cable, along with the balanced two-wire, is the most common type of transmission line used in RF communications. Altium Designer’s differential line impedance calculator will set up your impedance-controlled differential pair routing widths for you. 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. External Copper Thickness: Copper weight for the top and bottom layers. Assign the trace width and spacing that will make the impedance of the differential traces - the desired impedance. To calculate the impedance, I use Saturn PCB impedance calculator software, Inc - PCB Toolkit V8. Note: valid for (w/h) from 0. Also, be aware, 90 ohms is the differential impedance, the characteristic or single ended impedance will be more than half (ie. Eventually, the impedance of your power delivery network. PCB Trace Width Calculator & PCB Trace Resistance Calculator per IPC-2152 . Mitch Morey, San Diego, CA: I'm working on a board with 100-ohm differential signaling that I would like to design for microstrip routing. It is distributed along the trace and is inversely related to the cross-sectional area of the trace. 3. Tuning for your traces to the desired impedance value occurs by adjusting trace width and distance from the reference plane. The differential skew is adjusted with a tiny blip on one line towards the bottom of this image. Notes: 1) Calculation assumes traces are centered vertically. Thus a "differential pair" any long distance apart will have an impedance of 98 ohms, without any coupling between the lines, i. Here, we need to consider termination for the traces used in the above image, as well as the target impedance and skew limits between various traces. when two coupled tracks are used to give a differential impedance. As a compromise, at least for surface microstrip configurations, the value of the dielectric constant can be increased by approximately 14% in differential impedance calculators[2] to average the effect of the layers. Differential impedance is the ratio of voltage to current on a pair of transmission lines when driven in the differential. Microstrip Differential Impedance Formula. W is calculated to achieve a trace impedance (Z0) of ~50W and S is calculated to achieve a differential trace impedance of 90W. The impedance of each trace of the differential pair references to ground. Spacing between channels must be > 3x separation. 2 Ω impedance. Description. Differential impedance changes with coupling, which changes with trace separation. Instructions are below the calculator and don’t forget we can make and test your controlled impedance printed circuit boards too. There are four different types of impedance used in characterizing differential trace impedances. Trace thickness is 0. They will often lead you astray, unless you only have one trace on your board, or surrounding traces are a centimeter away. The accuracy of a controlled impedance trace on a PCB is usually critical to the correct performance of the PCB. This, by definition, gives a target of an odd mode impedance of 45 Ohms and an even mode of 60 Ohms. Include both the pcb dielectric thickness as well as the wire insulation in the height calculation. Impedance and PCB Stacking The trace impedance is affected by many factors such as the width of the trace, th e thickness of the copper, the PCB material, the PCB stacking specification, and the spacing between the differential pairs. For microstrip traces, a solid ground plane is needed under the signal traces. Single Ended Impedance Ω. 3 LVDS Traces • As shown in Figure 1, traces should be 100-Ω(±5%) differential impedance of differential microstrip or differential stripline. This is more than the to times trace width which is recommended (also read as close as possibly). • Ground planes must not be broken in the GND reference layer immediately beneath he transmission line. 2. 3mm, as shown below: This increases the impedance slightly to 91. This will also provide the time delay the cable provides for a signal and also the capacitance and inductance per. • Trace width of any un-coupled section of a differential trace greater than 100-mils, should be increased to maintain target impedanceLength-tuning structures and their effects on impedance. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. For differential pairs, there is also a spacing value given. Differential Impedance of. 68 mils. 5 Summary; Microstrip is the most popular medium for circuit design at frequencies ranging from several hundred megahertz to tens of gigahertz. Design and stackup in altium, For ex: 8 layers and impedance control of 100 ohms on layer 2 and 7 and ask your fabricator to suggest a stackup for same 8 layers and trace impedance of 100 ohms for layer 2 and 7 and compare the values. The following impedance calculators are. Therefore, for fast enough rise times, the impedance it offers can be significant. 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. Agilent's LineCalc tool calculates Z odd = 50. Stripline. With differential pairs, you also need to examine. In this design there is a coplanar ground plane a controlled distance away from the trace that is close enough that it significantly affects the impedance of the trace. I found that a W of 0. The Si8000m assumes negligible insertion loss in the transmission line; should you wish to model insertion loss the Si9000e adds. 3 shall be used. FWIW, the calculator I've used in the past is called Polar SI8000 which apparently has been superceded by Speedstack PCB. Figure 25 shows a differential pair using the microstrip layout. Z diff = 2* Z o (1 - 0. To obtain a particular value of differential impedance, the two signal tracks are usually assumed to have the same cross-section — the balanced track case, used in most impedance calculation software. But make sure you get the spacing between the diff pairs and their thickness (copper weight) correct. In this worst-vase scenario, the via would. Explore our high-quality products. Formula: Applicability: w ÷ t ≤ 0. Performing PCB trace length matching vs frequency correctly requires considering the entire bandwidth of a propagating signal on a trace. In such an arrangement for your target impedance the parallel traces would be 20 mil for 90 ohms diff. W is calculated to achieve a trace impedance (Z0) of ~50W and S is calculated to achieve a differential trace impedance of 90W. Given the defaults (1. 3 V, etc. Click on Setup -> Constraints > Electrical Constraints Set - > Differential Pair Value - > Calculator >. Edge Coupled Stripline Impedance Calculator. Use several of them and compare. A coplanar differential raises the diff impedance while lowering Zo with adjacent grounds so it needs a thinner height of dielectric. I am developing a 4-layer FR-4 board containing a GNSS receiver (L1 + L2). Impedance Calculator - Sierra Circuits. I've used ADI's Diff Amp Calculator since I started this circuit (quite a long time ago) and it helped a lot. Unit: Options are mm, mil, μm, and inch. 3mm of the microcontroller), therefore i rounded the width to 0. 3 shall be used. Speedstack is the stackup design tool of choice for professional PCB Designers fabricators and brokers who have a requirement to document and design stackups drill plans and material requirements complete with high. This works fine, I ordered impedance control several times - no need to change the width. (unloaded trace impedance, Ohms) = Tpd (unloaded propagation delay, ps/unit len) =. The cloder the two traces, the smaller is the differential impedance. Using 0. Now also calculates DC resistance with temperature compensation. Differential Stripline Impedance Calculator. I found that a W of 0. The High speed protocol that is being designed for determines what the single and differential trace Impedance the traces need to meet as well as the tolerance for the impedance (e. Right-click on ‘Net classes’ >> click on ‘Add classes. Reference layer. For an embedded (internal) microstrip, the formulas provided in paragraph 4. some trace calculation examples. 36) Co Equation: IPC-D-317A (Eq. View All Tools. In other words, if you are designing to hit a differential impedance target (such as. 1. Expect a large variation of manufactured PCB impedance with 0. Instead, field solvers normally focus on impedance and calculating the current distribution around the trace. If you put 10 in the Line Width, the calculator calculates the single ended as well as differential impedance. PCB stackup, signal integrity and controlled impedance: Signal integrity tools: Stackup design. 29 mm width traces to obtain 100 Ohms ZDiff while using 0. In general, it is double the odd-mode impedance, which is the value we care about for differential signaling, as it is used in high-speed PCB design. If you put that into the calculator, you will get much more practical values for the trace width. When calibrated,Differential Pair Routing. 6mm spacing with a trace width of 0. When you use a line calculator with a proper 'diff pair' mode, it will take account of the geometry and the correct driving conditions, and provide you with a pair of lines that has 100 ohms differential impedance, and two lines of 50 ohms impedance when the other line is driven with an inverted signal. Calculates the current a conductor needs to raise its temperature over ambient per IPC-2152. Figure 3 shows the respective p and T models used to calculate the differential impedance (Z diff). 8. d = Trace Separation. The vias on these differential pairs have their own impedance, which can create signal integrity problems on long interconnects. Target impedance and tolerance analysis for a particular trace . Sierra Circuits’ Via Impedance Calculator uses the physical dimensions of a via to calculate its capacitance, inductance, and impedance. Standard PCB HDI PCB Flexible PCB Rigid-Flex PCB Metal Core PCB Solder Paste Stencils High Frequency PCB Prototypes & Pilot Runs. Since this is the flex board it is very thin 8 mills total thickness, those it is difficult to create required hight to the reference plane. This calculator is designed to calculate the characteristic impedance of a broadside couple stripline (see diagram below). 50 Ohms) for high-frequency signals. Fabricators give trace impedance tables as guides to designers that need to implement controlled impedance in their PCBs. Trace Thickness (T) 2. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board layer, thickness, copper weight, target impedance, trace spacing (for edge-coupled pairs), and impedance trace to copper gap (coplanar waveguides). so i have had a look at a App-Note of the PHY chip: it contains a lot of good information - and for me its clear i have to do a differential pair for the TX+/TX- and RX+/RX- traces. Z 0 Differential impedance (Ω): Calculate. Differential Stripline Impedance Calculator. This assumes ~0 trace thickness. Yes, solder mask can lower the single line impedance by 1 - 2 ohms and the differential impedance by 3 - 4 ohms for thin traces. Gaps in signal traces impact the entire test waveform, and its single-point impedance is too high, making the entire waveform uneven. When the two lines are far apart (say, more than 3 or 4 trace widths), then the lines are weakly coupled and the individual line impedance is about 1/2 the pair. The test sample consists of a pair of differential traces at the top layer, followed by a differential via to the inner traces, then a second differential via connects to the BGA landing pads at the top layer again. I suggest interested parties find an online trace impedance calculator and play around with some geometries. Differential Trace Impedance . 25mm trace. Use the Series and Shunt Impedance Calculator: to try your own impedances; Change Grid: S11, (ZL normalized to source impedance Z0)Overview. The default units for all given values, except the subtrate. How to calculate track widths and layout controlled impedance traces (e. When two ends of a differential pair or a group of signal nets are mismatched, there will be excess skew between signals. This has been a research topic for differential serial protocols over the last several years, and standards like USB 4 place specific requirements on broadband signal integrity metrics. 94 mil) is nominal thickness of 3313 prepreg. Trace Impedance. 1. TheseIt always defaults to 10mil. Two 50 Ohm traces next to each other have a differential impedance of around 100 Ohms, or maybe a bit less. This calculator helps you calculate the characteristic impedance of a coaxial cable given its dimensions. This would be more manageable. One of the features of this type of microstrip is the coupling between lines. 6mm thick. In PCB design software with a built-in impedance calculator function, you can calculate impedance quickly. While commonly constructed using printed circuit boards, this structure can also be built using other materials as long as there is a conductor separated from. 2-side PCB, one side with signals, the other with GND. e. g. This is the same reason we have to consider spacing between traces in differential pairs: the two conductors interact with each other to determine the odd-mode (and differential) impedance . Differential Impedance: Single-ended Impedance: Significant field collisions (bad design--will be too much crosstalk): In short, do not put much faith in the single calculators you find online. Most popular calculators don’t even have a box height parameter. Notes: 1) Calculation assumes traces are centered vertically. The differential impedance depends upon the D/H ratio. 1 of the Microstrip Calculator using H2 in place of h, εr,eff can be computed as specified in Eq. To use this tool, enter the values for trace thickness, substrate height, trace width, trace spacing and subtrate dielectric in the calculator above and press the "calculate" button. Stripline Impedance. When selecting trace geometry, priority should be given to matching the differential impedance over the single ended impedance. 5. 75 mm track on a 0. The total length of the signal path is about 1,330mils. Embedded Microstrip. The characteristic impedance is given by: Eq. Missing by 25 microns on a 100 micron trace throws off the alignment by 25%. 3mm of the microcontroller), therefore i rounded the width to 0. Most popular calculators don’t even have a box height parameter. The amplitude of this crosstalk is what this tool calculates. Free Trace Line Impedance Calculators that utilize the #3 approach. Back to Resources Use our free impedance calculator to ensure your design is error-free! Impedance Calculator Structure Type Single Ended. Incidentally, the trace thickness parameter does have a significant effect. 96D/H) Zo. Differential signaling in flex circuits follows the design method of surface microstrip transmission lines. Every trace has series inductance. The differential via design shown in Figure 2 was built and tested. Differential impedance: This is the impedance of a pair of transmission lines. I would like to increase the width of my traces whilst maintaining the same ~50 Ohm nominal characteristic impedance of my line. 03) it gives me almost 160 Ohm - and even if use 53mil conductor height or. 4515. There are four different types of impedance. Physical geometries of differential traces To calculate the trace geometries in Figure 5 for a 100 Ω differential impedance TMDS signal pair, the closed-form equations 1 – 6 can. Then. some trace calculation examples. Understanding Coplanar Waveguide with Ground. See full list on resources. B = separation between reference planes. It is especially required when high-frequency signals propagate through a circuit board trace. 2H, the formula for the non-embedded. Cancel; Up 0 Down; Cancel;. If JLCPCB's 4-layer PCB is. You can use the differential impedance Calculator to find the differential impedance. Since it is always important that the trace impedance. 0 Dimensional units: mm milsDifferential Impedance Ω. To obtain a particular value of differential impedance, the two signal tracks are usually assumed to have the same cross-section — the balanced track case, used in most impedance calculation software. Trace impedance control is a simple matter of properly sizing traces. Following is the formula for differential impedance for a Microstrip. We recommend the software from Polar Instruments if you want to get exact impedance calculation. The Layer Stack Manager's impedance calculator uses the Wideband Debye model, with a default frequency. For example, with a thickness of 0. Let’s start new project together!The edge couple differential symmetric stripline transmission line is a common technique for routing differential traces. Unit: Options are mm, mil, μm,. The physical parameters of the trace i. 331 1 2 5. calculate the resulting differential impedance, and check that it matches the selected media (cable) differential mode characteristic impedance. This makes the problem of determining impedance much more complex, and building an initial lossless model requires a larger set of formulas from Wadell. Please bear in mind the copper trace, minimum etch, manufacturing capability etc of the pcb supplier. Choose a calculator to tune your PCB design. Note: Units do not matter for this calculation as long as they are consistent. The microstrip is a very simple yet useful way to create a transmission line with a PCB. No, the single-ended impedance provided in differential line calculators does not matter. 02 ; Height of substrate (thickness): 1. For this calculation, the units of d,h, t and w can be ignored as long as they have the same units (mils, mm, inches). 347 e -2. It supports both balanced and unbalanced lines. A Trace Length Calculator for Differential Pairs and Nets. Example Problem: Use the following variables as an example problem to.