ngspice analog circuit simulation
An ngspice study for analysing operating point, gain, bandwidth, transient response, noise, distortion, and component tolerance in a selected analogue circuit.
Software compatibility
The netlists, models, controls, and result scripts are prepared for ngspice 47. LTspice, PSpice, Multisim, and Cadence schematic project files are not included.
Project definition
Problem statement
Analogue-circuit behaviour changes with bias, device model, source and load impedance, frequency, signal level, temperature, and component tolerance.
Project objectives
- Model a selected transistor amplifier or active analogue circuit in native ngspice.
- Verify operating point and small-signal values against hand calculations.
- Run DC sweep, AC, transient, noise, and distortion analyses.
- Perform component-tolerance and selected temperature sweeps.
- Measure gain, bandwidth, stability proxies, noise, distortion, and yield.
System design
System modules
Circuit netlist
Defines devices, models, sources, supplies, loads, parameters, and test configurations.
Bias analyser
Runs operating-point and DC sweeps and checks device regions and power.
Frequency analyser
Calculates gain, phase, bandwidth, impedances, and selected stability indicators.
Transient and noise runner
Measures waveform, slew, clipping, distortion, and input or output noise.
Tolerance study
Samples component values and selected temperatures and calculates result distributions.
Methodology
System workflow
- 01Verify components
Models, pin order, units, supply, source, and load are checked.
- 02Establish bias
Operating point is compared with analytical estimates.
- 03Run linear study
AC gain, phase, bandwidth, and impedances are calculated.
- 04Run signal study
Transient, clipping, distortion, and noise are measured.
- 05Run tolerance study
Parameter samples produce performance and yield distributions.
Demonstration scenario
A transistor amplifier is biased and checked by hand, then its gain, bandwidth, transient clipping, and output noise are simulated. A tolerance study identifies which components dominate gain and cut-off variation.
Engineering
Technical architecture
- Environment
- Native ngspice 47 netlists, control scripts, model files, and raw outputs.
- Circuit model
- Documented semiconductor and passive models with source and load conditions.
- Automation
- ngspice batch runs and Python parsing, calculation, and plotting scripts.
- Verification
- Hand calculations, limiting cases, parameter-unit checks, and regression netlists.
Testing
Evaluation
Evaluation measures
- Operating-point agreement with analytical estimates
- Gain and bandwidth agreement with small-signal calculations
- Transient amplitude, clipping, distortion, and slew measures
- Integrated noise and noise-contribution checks
- Tolerance yield and sensitivity ranking
- Runtime and reproducibility across sweeps
System boundaries
- Only ngspice 47 netlists and result files are delivered.
- No proprietary schematic project is included.
- Device models are simulations and may not reproduce layout, parasitics, ageing, thermal coupling, or every manufactured part.
- Physical construction requires component ratings, electrical safety, measurement, and qualified review.
Included
- 01Native ngspice netlists and control files
- 02DC, AC, transient, noise, distortion, and tolerance analyses
- 03Gain, bandwidth, waveform, noise, and yield plots
- 04Prepared device models, test cases, and results
- 05Complete source code in a private GitHub repository
- 06Complete project documentation with synopsis, abstract, methodology, circuit diagrams, analytical calculations, simulation results, screenshots, and conclusion
- 07Setup and usage guide
Project record
No buyer information is collected on this page.
- Permanent project ID
- GP-EC-0MBTTED
- Catalogued
- 22 Aug 2026
- Completed
- Pending
- Verified
- Pending
- Demonstration
- Added when ready
Handover
After purchase
- 01Payment is confirmed
The project is marked unavailable and cannot be purchased again.
- 02Repository access is granted
The buyer's submitted GitHub account receives access to the private repository.
- 03The purchase record is delivered
The certification sheet is prepared from the reviewed buyer details and sent privately by email.