Reference manual

This document is Copyright © 2019 by it’s contributors as listed below. You may distribute it and/or modify it under the terms of either the GNU General Public License (http://www.gnu.org/licenses/gpl.html), version 3 or later, or the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), version 3.0 or later.

Contributors

Heitor de Bittencourt. Mathias Neumann

Feedback

Please direct any bug reports, suggestions or new versions to here:

Publication date and software version

march 04, 2019

## Introduction

The Kicad Calculator gives you the Chance to calculate the most important Things without leaving Kicad.

The Calculator consists the following Options:

• Regulators

• Track Width

• Electrical Spacing

• Trans Line

• RF Attenuators

• Color Code

• Board Classes

## Calculators

### Regulators

This calculator helps with the task of finding the values of the resistors needed for linear and low-dropout voltage regulators.

For the Standard Type, the output voltage V_out as a function of the reference voltage V_ref and resistors R_1 and R_2 is given by:

For the 3 terminal type, there is a correction factor due to the quiescent current I_adj flowing from the adjust pin:

This current is typically below 100 uA and can be neglected with caution.

To use this calculator, enter the parameters of the regulator Type, V_ref and, if needed, I_adj, select the field you want to calculate (one of the resistors or the output voltage) and enter the other two values.

### Track-Width

The Track Width calculator calculates the trace width for printed circuit board conductors for a given current. It uses formulas from IPC-2221 (formerly IPC-D-275).

### Electrical-Spacing

In the Picture you can see that you can edit the Voltage and the Calculator gives you the correct Values.

The minimal Values which orientatd at the IPC-2221 too.

### TransLine

Transmission line theory is a cornerstone in the teaching of RF and microwave engineering.

In the Calculator you can choose different sorts of Line Types and their special Parameters.

### RF-Attenuators

With the RF Attenuator you can calculate different things by choosing:

• PI

• Tee

• Bridged Tee

• Resistive Splitter

and change all their Parameters.

### Color-Code

This calculator helps translating the color bars from the resistor to its value. To use it, first select the tolerance of the resistor: 10%, 5% or equal or smaller than 2%. For example:

• Yellow Violet Red Gold: 4 7 x100 ±5% = 4700 Ohm, 5% tolerance

• 1kOhm, 1% tolerance: Brown Black Black Brown Brown