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SPICE Device Models: Diode Example–Part 1
2019.05.09
Points of this article
・There are two types of SPICE models: “device models” and “subcircuit models”.
・In SPICE device model, each parameter value is set.
In the previous article it was explained that models used in SPICE simulations can be device models or subcircuit models. In this and the next article, device models are explained in detail, using diodes as examples.
SPICE Device Models: Principle of Operation of Diodes
Diodes are used as examples to explain how SPICE device models are constructed. To this end, we first review the principle of operation of a diode. Here semiconductor theory is involved, but what is important is the parameters used in the device model, and so there is no real need for an understanding of the theory itself.
The diagram below illustrates the basic principle of operation of a silicon diode. When a bias voltage is applied to the diode, the electric field in the depletion layer weakens, carrier diffusion occurs, and a current flows. The forward current Id and the depletion layer capacitance Cj of the diode can be expressed by the following equations.
Model equations are essentially the same as semiconductor theoretical equations. In a device model, these parameter values are set.
SPICE Device Models: Case Study of Diode Device Model
A device model of an actual diode is presented. This model is provided by ROHM.
Although mentioned in the list of description rules, lines beginning with an asterisk (*) are commented out. Simple explanations of the model and the like can be provided as desired. In this example, the actual description begins with “MODEL”. Lines beginning with pluses (+) set parameter values. Please compare the device model description and the parameter table. When a default value can be used as the parameter setting, a value need not be stated.
(Continued to Part 2)
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Electrical Circuit Design
- Soldering Techniques and Solder Types
- Seven Tools for Soldering
- Seven Techniques for Printed Circuit Board Reworking
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Basic Alternating Current (AC)
- AC Circuits: Alternating Current, Waveforms, and Formulas
- Complex Numbers in AC Circuit
- Electrical Reactance
- What is Impedance? AC Circuit Analysis and Design
- Impedance Measurement: How to Choose Methods and Improve Accuracy
- Impedance Matching: Why It Matters for Power Transfer and Signal Reflections
- Resonant Circuits: Resonant Frequency and Q Factor
- RLC Circuit: Series and Parallel, Applied circuits
- What is AC Power? Active Power, Reactive Power, Apparent Power
- Power Factor: Calculation and Efficiency Improvement
- What is PFC?
- Boundary Current Mode (BCM) PFC: Examples of Efficiency Improvement Using Diodes
- Continuous Current Mode (CCM) PFC: Examples of Efficiency Improvement Using Diode
- LED Illumination Circuits：Example of Efficiency Improvement and Noise Reduction Using MOSFETs
- PFC Circuits for Air Conditioners：Example of Efficiency Improvement Using MOSFETs and Diodes
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Basic Direct Current (DC)
- Ohm’s Law: Voltage, Current, and Resistance
- Electric Current and Voltage in DC Circuits
- Kirchhoff’s Circuit Laws
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- Thevenin’s Theorem: DC Circuit Analysis
- Norton’s Theorem: Equivalent Circuit Analysis
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- What Is the Δ–Y Transformation (Y–Δ Transformation)?
- Voltage Divider Circuit
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Thermal design
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About Thermal Design
- Changes in Engineering Trends and Thermal Design
- A Mutual Understanding of Thermal Design
- Fundamentals of Thermal Resistance and Heat Dissipation: About Thermal Resistance
- Fundamentals of Thermal Resistance and Heat Dissipation: Heat Transmission and Heat Dissipation Paths
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Conduction
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Convection
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Emission
- Thermal Resistance Data: JEDEC Standards, Thermal Resistance Measurement Environments, and Circuit Boards
- Thermal Resistance Data: Actual Data Example
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- Thermal Resistance Data: θJA and ΨJT in Estimation of TJ: Part 1
- Thermal Resistance Data: θJA and ΨJT in Estimation of TJ: Part 2
- Surface Temperature Measurements: Methods for Fastening Thermocouples
- Surface Temperature Measurements: Thermocouple Mounting Position
- Surface Temperature Measurements: Treatment of Thermocouple Tips
- Surface Temperature Measurements: Influence of the Thermocouple
- Estimating TJ: Basic Calculation Equations
- Estimating TJ: Calculation Example Using θJA
- Estimating TJ: Calculation Example Using ΨJT
- Estimating TJ: Calculation Example Using Transient Thermal Resistance
- Estimation of Heat Dissipation Area in Surface Mounting and Points to be Noted
- Surface Temperature Measurements: Thermocouple Types
- Summary
- Collection of Important Points Relating to Thermal Design
Switching Noise
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Dealing with Noise Using Capacitors
- Understanding the Frequency Characteristics of Capacitors, Relative to ESR and ESL
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- Effective Use of Decoupling (Bypass) Capacitors Point 1
- Effective Use of Decoupling Capacitors Point 2
- Effective Use of Decoupling Capacitors, Other Matters to be Noted
- Effective Use of Decoupling Capacitors, Summary
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Dealing with Noise Using Inductors
- Frequency-Impedance Characteristics of Inductors and Determination of Inductor’s Resonance Frequency
- Basic Characteristics of Ferrite Beads and Inductors and Noise Countermeasures Using Them
- Dealing with Noise Using Common Mode Filters
- Points to be Noted: Crosstalk and Noise from GND Lines
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Simulation
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Foundations of Electronic Circuit Simulation Introduction
- About SPICE
- SPICE Simulators and SPICE Models
- Types of SPICE simulation: DC Analysis, AC Analysis, Transient Analysis
- Types of SPICE simulation: Monte Carlo
- Convergence Properties and Stability of SPICE Simulations
- Types of SPICE Model
- SPICE Device Models: Diode Example–Part 1
- SPICE Device Models: Diode Example–Part 2
- SPICE Subcircuit Models: MOSFET Example―Part 1
- SPICE Subcircuit Models: MOSFET Example―Part 2
- SPICE Subcircuit Models: Models Using Mathematical Expressions
- About Thermal Models
- About Thermal Dynamic Model
- Summary
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About the ROHM Solution Simulator
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- Trying Out the ROHM Solution Simulator (1)
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- Exporting Circuit Data to PartQuest™ Explorer
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- Optimization of PFC Circuits
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- About Thermal Simulations of DC-DC Converters
- Circuit-Theory-Based Design Simulation