MiscEl: Cable calculations

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Calculations on a cable, one or two wires with otional shield.
The cable is simulated with a number of seperate RLC sections

Analyze input fields

CCapacity between wires for one meter cable
CshieldCapacity between one wire and shield
LInductance for one meter cable
RcableDC resistance for one meter of wire
RshieldDC resistance for one meter of shield
LengthTotal length of cable
RsSource impedance
RlLoad impedance
Curve plotShow a curveplot of frequence responce
WaveformsTry cable with different waveforms
Input/outputUse a complex source/load network

Analyze output fields

-3 dB FreqThis is calculated form RCL and ignoring any transmission line effects
Cable ZoImpedance of cable at specified frequence
Signal velocitySpeed of signal at specified frequence, shown in absolute speed and percent of c
GainGain of cable (Will be below 1)
PhasePhase of output signal
Signal in BCrosstalk to B wire
Phase of BPhase of signal in B wire
Signal in gndSignal in gnd connection

Signal input fields

This tab will do a more detailed analysis with a specific signal.
FreqCalculate cable parameters and transmission fr this frequence
Volt (RMS)Analyze with this voltage
dBmSpecify signal as dB with reference at 1mW over 600 ohm

Signal output fields

RMS voltageRMS voltage and dB level (Ref: 1mW over 600 ohm)
Peak-peak voltageAbove value multiplied by sqrt(8)
Slew rateThe maximum slew rate of the voltage
Source cable i/Source cable currentMaximum current going into the cable to charge/discharge the cable capacity
Source load currentMaximum current used to supply the load
Noise floorComparing the signal to "Johnson" noise

Config

LimitUsed when calculating cutoff frequence, usual 3 dB
Freq nAnalyze at these frequences, write DC to do a DC analyse
SectionsHow many section to do the calculations on, more sections give better result but are slower

Zo to L

Convert a Zo specification to inductance
ZoImpedance of cable
CCapacitance of cable
RDC resistance of cable
Copy to analyzeCopy entered and calculated parameters to analyze page

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