SIMetrix/SIMPLIS 9.40b – fast switching power-supply simulator

Description

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SIMetrix/SIMPLIS 9.40b is the July 23, 2026 maintenance build of the leading switching power supply simulator and analog/mixed-signal design environment. Version 9.4 opened the product to native Python automation. 9.40b is the service release teams install when they want that Python workflow, plus the classic SIMPLIS speed advantage, on a quieter production build.

If you design DC-DC converters, PFC stages, isolated SMPS, POL regulators, or mixed-signal power ICs, this is the tool built for the circuits SPICE struggles to finish.

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⚡ Why engineers search for SIMetrix/SIMPLIS

SIMetrix/SIMPLIS puts two engines in one schematic:

• SIMetrix — enhanced SPICE for analog and mixed-signal work, hierarchical schematics, and waveform viewing
• SIMPLIS — piecewise-linear simulator purpose-built for switching power electronics

SIMPLIS (SIMulation of Piecewise LInear Systems) typically runs transient analysis 10–50× faster than SPICE on switching converters and converges more reliably. That is why it became the default simulator for closed-loop power supplies: large, realistic designs become practical instead of overnight jobs.

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🐍 What’s new in 9.4 / 9.40 — Python integration

This is the headline of the 9.4 family.

You can now program SIMetrix and SIMetrix/SIMPLIS in Python, not only the legacy script language. Dedicated object-oriented classes reach:

• the schematic editor
• the waveform viewer
• the data-handling system
• both the SIMetrix and SIMPLIS simulators
• measurement results after a run

A built-in Python editor includes syntax highlighting, syntax checking, method completion, and popup documentation. Python is installed separately. Officially supported versions are 3.12, 3.13, and 3.14. Scripts can call every SIMetrix script function and command. SIMetrix scripts can launch Python with PythonExecFile / PyExec. A simetrix package on PyPI adds editor language support.

Python automation ships with Classic, Pro, and Elite. Typical uses: sweep a magnetics library, batch POP + AC on every variant, dump efficiency tables, drive Monte Carlo from NumPy/pandas, or generate customer reports without leaving the tool.

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🛠️ What 9.40b actually changes

v9.40b (23 July 2026) is officially a maintenance and stability update, not a second feature dump. Install it when you want the 9.4 Python platform with fewer rough edges for long simulations, editor sessions, and scripted runs.

Vendor notes do not publish a public bug-ID table for the “b” letter. Treat 9.40b as the recommended 9.4-family build for in-maintenance licenses. A later 9.40c patch (1 September 2026) continues the same maintenance line.

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🎯 Core highlights that still sell the product

🚀 Speed on switching circuits
Piecewise-linear device models keep the system of equations linear between breakpoints. Transient runs on multi-phase bucks, ZVS full bridges, and similar topologies routinely finish in seconds instead of minutes.

📍 Periodic Operating Point (POP)
POP finds the periodic steady-state waveforms of a switching system without simulating the entire startup transient. That is the analysis you want before you trust efficiency, ripple, or magnetics stress.

📈 AC / Bode from the real switching model
SIMPLIS AC analysis operates on the full nonlinear time-domain switching circuit. You do not derive an averaged model. Frequency can vary. Ripple does not have to be “small.” Bode, output impedance, and input impedance look like bench measurements—especially valuable for PFC, burst mode, and digital control, where textbook average models break.

🔄 SPICE model conversion
Place many vendor MOSFET, IGBT, BJT, JFET, diode, Schottky, and Zener SPICE models and convert them into SIMPLIS format by extracting characteristics automatically.

🧩 One GUI
Hierarchical schematic editor, symbol editor, waveform viewer, probes, Monte Carlo / multi-step, and (on Pro/Elite) multi-core sweeps live in the same environment as both simulators.

🔌 Optional add-ons
Design Verification Module (DVM), Magnetics Design Module (MDM), and SIMPLIS VH Verilog-HDL co-simulation extend the same license family.

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🐛 Bug fixes & stability (honest version)

9.40b is sold as stability first. Expect:

• fewer crashes on long POP / transient / multi-step jobs
• cleaner behavior around the new Python editor and embedded interpreter
• maintenance fixes accumulated after the initial 9.4 release

If you need a public CVE-style changelog, the vendor does not publish one for this lettered patch. For production seats, “latest supported 9.40 service release” is the practical answer—and on the SIMPLIS downloads page that was v9.40b through July–August 2026.

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💻 System requirements

Operating system

• Windows 11 Home, Pro (and variants), Enterprise
• Windows 10 Home, Pro, Enterprise — 64-bit only

CPU (version 9.1 and later, including 9.40b)
One of:

• Intel 4th-generation Core i3/i5/i7/i9 or later (Haswell+)
• Intel Xeon E3 / E5 / E7 v3 or later
• AMD Piledriver microarchitecture or later

Systems built from about 2014–2015 onward usually qualify. SIMetrix/SIMPLIS is CPU-heavy; more cores help Pro/Elite multi-step and Monte Carlo.

Python (for the 9.4 automation feature)
Install Python 3.12, 3.13, or 3.14 separately.

Display / hardware
Any machine that meets Windows’ own minimums will launch. Large RAM helps when you cache big waveform dumps. A fast disk helps a little; the CPU dominates.

ARM64 Windows
Can run under emulation on Windows 11 version 25H2 or later with newer emulation features enabled. Not fully supported—issues must be reproducible on a supported x64 OS for official help.

Licensing note
Portable (USB/dongle) upgrades across major versions have special install instructions. Network seats use FlexNet. Full vendor support assumes a supported OS on physical hardware, not an unsupported VM stack.

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🧠 Interesting facts (the kind that stick in search snippets)

• SIMPLIS is an acronym: SIMulation of Piecewise LInear Systems. Every nonlinear device is a chain of straight-line segments, so the solver is always tackling a linear system between events.
• SIMPLIS AC analysis does not assume constant switching frequency or negligible feedback ripple—the two assumptions that break many averaged models on modern converters.
• Official timing examples on multi-phase bucks and a ZVS full bridge show POP, AC, and transient finishing in seconds, which is why closed-loop SMPS design moved here from generic SPICE.
• Python in 9.4 is embedded in the SIMetrix process (fast, shared memory), not a loose external remote-control hack. Abort with Escape only works if the script periodically calls back into SIMetrix; a tight pure-Python loop can only be killed from Task Manager.
• A free SIMetrix/SIMPLIS Elements edition exists for evaluation (circuit-size limits, no command line / Python / Verilog-A on the free SKU). Full 9.40b is the licensed product.

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✅ Who should buy 9.40b

Power electronics engineers, analog IC designers working on power-management silicon, and labs that already own a SIMetrix/SIMPLIS maintenance contract. Upgrade if you want Python-driven power-supply simulation, POP and switching-model AC analysis, and 10–50× faster SMPS transients than conventional SPICE—on the July 2026 stability build of version 9.4.

SIMetrix/SIMPLIS 9.40b — professional circuit simulation for switching power supplies, with Python automation, POP steady-state, full-model AC Bode plots, and a maintenance release meant for daily design work.

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⭐⭐⭐⭐⭐ Closed-loop SMPS work actually finishes in a sitting

We moved flyback and multi-phase buck design off generic SPICE and onto SIMetrix/SIMPLIS. Transient runs are routinely an order of magnitude faster, POP finds steady state without waiting through startup, and AC Bode plots come from the real switching model—no hand-built averaged plant. Schematic + waveforms live in one window; SPICE MOSFET/diode conversion is good enough for first-pass magnetics and loop work. Version 9.4 Python scripting is the first automation layer that feels native. Windows-only and the license/dongle dance are the usual CAD tax. For power-supply engineers this is still the tool I recommend.