# QSPICE Circuit Simulation: A Spicy Discussion with Mike Engelhardt

- Show: [Moore's Lobby](https://hardwarepodcasts.com/podcast/moores-lobby)
- Published: 2024-07-30
- Length: 55m
- Episode: 15
- Page: https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt
- Listen: https://www.allaboutcircuits.com/podcast/qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt

## Summary

Mike Engelhardt, creator of LTspice and now QSPICE at Qorvo, explains how he built circuit simulation tools starting from his work in physics labs and oil exploration. He details the rapid development of LTspice in 10 months to serve as sales collateral for Linear Technology, emphasizing that simulation's primary value is building engineer intuition rather than just verification. Engelhardt then describes refactoring the open-source Berkeley SPICE code to create QSPICE, which fixes bugs in the sparse matrix package and leverages GPUs for waveform plotting rather than computation to handle wide bandgap semiconductors like GaN and SiC.

## Chapters

- [0:01](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=1) Introduction and Early Career
- [2:14](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=134) Simulation in Physics and Oil Exploration
- [9:34](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=574) Creating LTspice at Linear Technology
- [13:32](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=812) The Philosophy of Simulation and Intuition
- [27:10](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=1630) Developing QSPICE and Refactoring SPICE
- [35:02](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=2102) GPU Usage and Qorvo's Business Model
- [46:02](https://hardwarepodcasts.com/podcast/moores-lobby/2024-07-30-qspice-circuit-simulation-a-spicy-discussion-with-mike-engelhardt#t=2762) Power Electronics and Wide Bandgap Devices

## Topics

- [EDA & CAD tools](https://hardwarepodcasts.com/topic/eda-and-cad-tools)
- [Analog & power electronics](https://hardwarepodcasts.com/topic/analog-and-power-electronics)
- [Careers & education](https://hardwarepodcasts.com/topic/engineering-careers-and-education)
- [Chips, FPGAs & semiconductors](https://hardwarepodcasts.com/topic/chips-and-fpgas)

## Most relevant to

early-stage companies, companies scaling up

## Mentioned

- LTspice (product)
- QSPICE (product)
- Linear Technology (company)
- Qorvo (company)
- Berkeley SPICE (product)
- GaN (chip)
- SiC (chip)

## Related episodes from other shows

- [An Interview with Mike Engelhardt - SPICE Simulator Synteresis](https://hardwarepodcasts.com/podcast/the-amp-hour/2014-04-30-an-interview-with-mike-engelhardt-spice-simulator-synteresis) (The Amp Hour)
- [An Interview with Mike Engelhardt (Re-broadcast)](https://hardwarepodcasts.com/podcast/the-amp-hour/2022-07-31-an-interview-with-mike-engelhardt-re-broadcast) (The Amp Hour)
- [An Interview with Matt Duff](https://hardwarepodcasts.com/podcast/the-amp-hour/2018-05-14-an-interview-with-matt-duff) (The Amp Hour)
- [Mute Button Discipline](https://hardwarepodcasts.com/podcast/the-amp-hour/2022-05-16-mute-button-discipline) (The Amp Hour)
- [T-25-010 :  Ioannis Papamanoglou and Narayan Powderly - Engineers transforming how we design, test, and build hardware with atopile](https://hardwarepodcasts.com/podcast/tradeoffs/2026-01-01-t-25-010-ioannis-papamanoglou-and-narayan-powderly-engineers-transforming-how-we) (TRADEOFFS)

## Citing this page

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