Calcolatrice per Circuiti Stampati

The KiCad Team

Manuale di riferimento

Copyright

Questo documento è coperto dal Copyright © 2019 dei suoi autori come elencati in seguito. È possibile distribuirlo e/o modificarlo nei termini sia della GNU General Public License (https://www.gnu.org/licenses/gpl.html), versione 3 o successive, che della Creative Commons Attribution License (https://creativecommons.org/licenses/by/3.0/), versione 3.0 o successive.

Contribuitori

Heitor de Bittencourt. Mathias Neumann

Traduzione

Marco Ciampa <ciampix@posteo.net>, 2019.

Feedback

Si prega di inviare qualsiasi rapporto bug, suggerimento o nuova versione a:

Sulla documentazione di KiCad: https://gitlab.com/kicad/services/kicad-doc/issues

Sul software KiCad: https://gitlab.com/kicad/code/kicad/issues

Sulla traduzione del software di KiCad: https://gitlab.com/kicad/code/kicad-i18n/issues

Data di pubblicazione e versione del software

March 05 2020

1. Introduzione

The KiCad PCB Calculator is a set of utilities to help you find the values of components or other parameters of a layout. The Calculator has the following tools:

Regolatori

Larghezza piste

Spaziature elettriche

Linee di trasmissione

Attenuatori RF

Codice colori

Classi schede

2. Calcolatrici

2.1. Regolatori

Questa calcolatrice serve ad aiutare a trovare i valori delle resistenze necessarie per i regolatori lineari, inclusi quelli a bassa caduta.

For the Standard Type, the output voltage Vout as a function of the reference voltage Vref and resistors R1 and R2 is given by:

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

Questa corrente solitamente è sotto i 100 uA e può essere ignorata con cautela.

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

2.2. Larghezza piste

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

2.3. Spaziature elettriche

This table helps finding the minimum clearance between conductors.

Each line of the table has a minimum recomended distance between conductors for a given voltage (DC or AC peaks) range. If you need the values for voltages higher than 500V, enter the value in the box in the left corner and press Update Values.

2.4. Linea di trasmissione

La teoria delle linee di trasmissione è una pietra miliare nell’insegnamento dell’ingegneria RF e delle microonde.

Nella calcolatrice si può scegliere tra diversi tipi di linee ed i loro parametri speciali. I modelli implementati dipendono dalle frequenze e quindi non corrispondono con i modelli più semplici a frequenze abbastanza alte.

Questa calcolatrice è fortemente basata su Transcalc.

I tipi di linee di trasmissione ed i riferimenti dei loro modelli matematici sono elencati di seguito:

Microstrip line:

H. A. Atwater, “Simplified Design Equations for Microstrip Line Parameters”, Microwave Journal, pp. 109-115, November 1989.

Guida d’onda coplanare.

Guida d’onda coplanare con piano di massa.

Rectangular waveguide:

S. Ramo, J. R. Whinnery and T. van Duzer, "Fields and Waves in Communication Electronics", Wiley-India, 2008, ISBN: 9788126515257.

Linea coassiale.

Coupled microstrip line:

H. A. Atwater, “Simplified Design Equations for Microstrip Line Parameters”, Microwave Journal, pp. 109-115, November 1989.

M. Kirschning and R. H. Jansen, "Accurate Wide-Range Design Equations for the Frequency-Dependent Characteristic of Parallel Coupled Microstrip Lines," in IEEE Transactions on Microwave Theory and Techniques, vol. 32, no. 1, pp. 83-90, Jan. 1984. doi: 10.1109/TMTT.1984.1132616.

Rolf Jansen, "High-Speed Computation of Single and Coupled Microstrip Parameters Including Dispersion, High-Order Modes, Loss and Finite Strip Thickness", IEEE Trans. MTT, vol. 26, no. 2, pp. 75-82, Feb. 1978.

S. March, "Microstrip Packaging: Watch the Last Step", Microwaves, vol. 20, no. 13, pp. 83.94, Dec. 1981.

Stripline.

Doppino ritorto.

2.5. Attenuatori RF

With the RF Attenuator utility you can calculate the values of the resistors needed for different types of attenuators:

Pigreco

T

T interconnesso

Accoppiatore resistivo

To use this tool, first select the type of attenuator you need, then enter the desired attenuation (in dB) and input/output impedances (in Ohms).

2.6. Codice colori

Questa calcolatrice aiuta nella traduzione delle barre di colore presenti sulle resistenze nel loro valore. Per usarla, basta selezionare la tolleranza della resistenza: 10%, 5% o minore o uguale al 2%. Per esempio:

Giallo viola rosso oro: 4 7 x100 ±5% = 4700 Ohm, 5% di tolleranza

1kOhm, 1% tolleranza: marrone nero nero marrone marrone

2.7. Classi schede

Performance Classes

In IPC-6011 have been three performance classes established

Class 1 General Electronic Products Includes consumer products, some computer and computer peripherals suitable for applications where cosmetic imperfections are not important and the major requirement is function of the completed printed board.

Class 2 Dedicated Service Electronic Products Includes communications equipment, sophisticated business machines, instruments where high performance and extended life is required and for which uninterrupted service is desired but not critical. Certain cosmetic imperfections are allowed.

Class 3 High Reliability Electronic Products Includes the equipment and products where continued performance or performance on demand is critical. Equipment downtime cannot be tolerated and must function when required suchas in life support items or flight control systems. Printed boards in this class are suitable for applications where high levels of assurance are required and service is essential.

PCB Types

In IPC-6012B there are also 6 Types of PCB defined:

Printed Boards without plated through holes (1)

1 Single-Sided Board

And Boards with plated through holes (2-6)

2 Double-Sided Board

3 Multilayer board without blind or buried vias

4 Multilayer board with blind and/or buried vias

5 Multilayer metal core board without blind orburied vias

6 Multilayer metal core board with blind and/orburied vias