Cadence Allegro PCB Tips & Tricks

Cadence Allegro is a very powerfull PCB design software. However, it is not very intuitive. Here are some Cadence Allegro PCB Tips & Tricks that I wrote down for myself to remember. I will update them to include new items as soon as I would like to memorize more. Read more

Individual Component Temperature Set/Sweep in LTSPICE simulation

LTSPICE allows to set individual device temperature. However, this possibility is not described in documentation. Read more

Passing Parameters to Hierarchical Block in LTSPICE

There were a couple of questions on how to pass parameters to Hierarchical Blocks from main level schematic in LTSPICE. In fact, until recently, I was having troubles doing this. But solution is very simple and strait forward. Read more

Undocumented LTSPICE features-solving some of convergence problems using backward Euler integration method.

LTSPICE is surprisingly flexible simulator but some of important options are not described in documentation. One of them is additional method of integration that you can use to address convergence problems. This method is called backward Euler. Read more

In the search of “Holy Grail” of output stages, evaluating performance of Power Amplifier output stages for High-End applications

Performance of output stage plays a significant role in overall performance of audio power amplifier and, together with VAS output stage, may be considered to be the major source of distortions. Read more

Realistic SPICE model for TL431: stability, noise, impedance and performance simulation of TL431 shunt regulator

TL431 is commonly used to create a voltage reference or small linear shunt regulator. It is often considered to be a “programmable zener”. Though, there is a big difference between TL431 and a zener diode. As many of other feedback systems, TL431 can oscillate if inappropriately decoupled. Read more

RC Cut-Off Frequency & Time Constant Calculator

If you are estimating stability of feedback system, determining bandwidth or decoupling components for your circuit, RC time constant or cut-off frequency is one of essential parameters. This calculator will help you to evaluate cut-off frequency and time constant of RC circuit. Read more

Audio Total Harmonic Distortion Analyzer for LTSPICE, making THD vs. Amplitude and Frequency sweeps in LTSPICE

FFT capabilities integrated into LTSPICE simulator are nice and flexible. However, if you would like to evaluate frequency or amplitude dependence of distortions, you have to take these measurements point by point and then manually plot them.

I created an LTSPICE add-on to automate THD measurements and plot result in the form of THD vs. Amplitude and THD vs. Frequency graphs. Read more

Adventures with .MEASURE in LTSPICE

.MEASURE or .MEAS is a very convenient and one of the few options for built in post processing of simulation results in LTSPICE. Though, you should be careful, while using it. Read more

Baxandall inspired tone control – response simulation

Here is an example of parametric sweep, showing one possible way of potentiometer and variable resistor simulation in LTSPICE. I will use commonly referenced tone control, originally suggested by James and modified by Baxandall to utilize active tone control scheme. Read more

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