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What layperson-friendly tools are out there to simulate simple analog circuits? For years now I've been going to the ancient app at https://www.falstad.com/cir

What layperson-friendly tools are out there to simulate simple analog circuits? For years now I've been going to the ancient app at https://www.falstad.com/circuit/ https://www.falstad.com/circuit/ but wondering that surely there must be something that Real Electronics Builders use. (I intentionally did not say Engineers because I assume that would be covered by the pricy and/or UI-challenged tools like spice and company).

dhdc 4y ago
I'm afraid there really isn't any hobbiest simulators out there. A lot of these arrangements rely on the intrinsic characteristics and geometry of the MOSFETs used.
nomel 4y ago
For simple circuits, LTspice: https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html https://www.analog.com/en/design-center/design-tools-and-cal... And it's definitely used by real engineers. It's for making switching power supplies, so it can handle fairly complex circuits. I wouldn't venture into RF/high speed circuits with it though, since the included parasitics aren't sufficient. And, custom functions are supported, so, I believe, you can put whatever maths in a component (I've never ventured this far): https://ltwiki.org/index.php?title=B_sources_(complete_reference) https://ltwiki.org/index.php?title=B_sources_(complete_refer...
- SAI_Peregrinus 4y ago
  One can also use KiCAD to generate netlists for other SPICE tools like ngspice. Most EDA packages will include some sort of simulator, often SPICE-based. The fancier ones for RF work include or integrate with field solvers.
- madengr 4y ago
  The parasitics all depend on the model, as I used LTSpice recently for an RFIC class for a 5 GHz LNA. The .net directive allows two-port analysis and even a Smith chart. Though Microwave Office is my go-to tool.
achr2 4y ago
circuitlab.com is great for simple designs. Not as powerful as some SPICE simulators, but amazingly convenient.
- compumike 4y ago
  (CircuitLab developer here.) Thank you for the kind words! :) Clickable link: https://www.circuitlab.com/ https://www.circuitlab.com/ if anyone wants to give it a try. As far as the linked article "Fifty Nifty Variations of Two-Transistor Circuits: A tribute to the versatility of MOSFETs", I will mention that CircuitLab does NOT currently provide a MOSFET model that includes a separate body terminal. Instead, the body (also sometimes called the "back gate") and source terminals are assumed to always be internally connected in the CircuitLab MOSFET models, resulting in a three-terminal device. Almost all real-world discrete MOSFETs you can buy are also three-terminal (gate/drain/source), not four (gate/drain/source/body). Some discussion here https://electronics.stackexchange.com/questions/137161/why-are-discrete-four-terminal-mosfets-so-hard-to-find https://electronics.stackexchange.com/questions/137161/why-a... and here https://electronics.stackexchange.com/questions/185109/mosfet-with-actual-pin-for-body https://electronics.stackexchange.com/questions/185109/mosfe... but not especially satisfying in my opinion. As a result, Figures 2, 16, 27, 29, 46, 49, and 50 can NOT currently be realized within CircuitLab.
drhodes 4y ago
There is JADE (for education), which can be integrated into a blog or for teaching on the web. It supports hierarchical custom analog and digital modules, a convenient way to create test vectors, (docs for that are floating around) This tool was used by students to build and grade the BETA CPU. https://computationstructures.org/exercises/sandboxes/jade.html https://computationstructures.org/exercises/sandboxes/jade.h...

dhdc 4y ago

I'm afraid there really isn't any hobbiest simulators out there. A lot of these arrangements rely on the intrinsic characteristics and geometry of the MOSFETs used.

nomel 4y ago

For simple circuits, LTspice: https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html https://www.analog.com/en/design-center/design-tools-and-cal... And it's definitely used by real engineers. It's for making switching power supplies, so it can handle fairly complex circuits. I wouldn't venture into RF/high speed circuits with it though, since the included parasitics aren't sufficient. And, custom functions are supported, so, I believe, you can put whatever maths in a component (I've never ventured this far): https://ltwiki.org/index.php?title=B_sources_(complete_reference) https://ltwiki.org/index.php?title=B_sources_(complete_refer...

SAI_Peregrinus 4y ago
One can also use KiCAD to generate netlists for other SPICE tools like ngspice. Most EDA packages will include some sort of simulator, often SPICE-based. The fancier ones for RF work include or integrate with field solvers.
madengr 4y ago
The parasitics all depend on the model, as I used LTSpice recently for an RFIC class for a 5 GHz LNA. The .net directive allows two-port analysis and even a Smith chart. Though Microwave Office is my go-to tool.

achr2 4y ago

circuitlab.com is great for simple designs. Not as powerful as some SPICE simulators, but amazingly convenient.

compumike 4y ago
(CircuitLab developer here.) Thank you for the kind words! :) Clickable link: https://www.circuitlab.com/ https://www.circuitlab.com/ if anyone wants to give it a try. As far as the linked article "Fifty Nifty Variations of Two-Transistor Circuits: A tribute to the versatility of MOSFETs", I will mention that CircuitLab does NOT currently provide a MOSFET model that includes a separate body terminal. Instead, the body (also sometimes called the "back gate") and source terminals are assumed to always be internally connected in the CircuitLab MOSFET models, resulting in a three-terminal device. Almost all real-world discrete MOSFETs you can buy are also three-terminal (gate/drain/source), not four (gate/drain/source/body). Some discussion here https://electronics.stackexchange.com/questions/137161/why-are-discrete-four-terminal-mosfets-so-hard-to-find https://electronics.stackexchange.com/questions/137161/why-a... and here https://electronics.stackexchange.com/questions/185109/mosfet-with-actual-pin-for-body https://electronics.stackexchange.com/questions/185109/mosfe... but not especially satisfying in my opinion. As a result, Figures 2, 16, 27, 29, 46, 49, and 50 can NOT currently be realized within CircuitLab.

drhodes 4y ago

There is JADE (for education), which can be integrated into a blog or for teaching on the web. It supports hierarchical custom analog and digital modules, a convenient way to create test vectors, (docs for that are floating around) This tool was used by students to build and grade the BETA CPU. https://computationstructures.org/exercises/sandboxes/jade.html https://computationstructures.org/exercises/sandboxes/jade.h...