Some devices are simple models defined by a number of commonly used parameters. These use the Edit Device Parameters dialog described below to edit the common parameter values of the following parameterised components.
- Delayed Switch
- Electrolytic Capacitor (Ladder)
- Electrolytic Capacitor (Level 1-3)
- Electrolytic Capacitor (Level 4-5)
- Lossy Inductor
- Parameterised Opamp
- Peak To Peak Voltage Source
- Sine Wave Burst Voltage Source
- Sine Wave Sweep Voltage Source
- Switch With Hysteresis
- Transmission Line (LossLess)
- Transmission Line (Lossy RLC)
- Watch Voltage, Watch Current and Watch Differential Voltage.
These components are defined using one of the built-in Spice functions. e.g Opamp - Parameterised. The parameters for these devices are explained below.
Shortcuts
Default Keys: F7
Default Menu: Simulation
Command: Edit Spice Value/Model
How To Change A Parameterised Device
Select the Parameterised Component(s) that you wish to change. If multiple components are selected they must all be the same Spice built-in type.
Press F7 or use the Edit Spice Value/Model option from the Simulation menu, or from the shortcut menu.
A dialog will be displayed with edit controls for the common device parameters.
Delayed Switch
These components have their Spice Type set to use the Delayed Switch built-in function.
This component uses the generic “delayed_switch” model.
Electrolytic Capacitor (Ladder)
These components have their Spice Type set to use the Capacitor - Electrolytic (Ladder Model) built-in function.
This device uses a Spice Template to define a subcircuit containing a ladder network of capacitors (and optionally inductors) with the given number of sections by using the repeat function.
Electrolytic Capacitor (Level 1-3)
These components have their Spice Type set to use the Capacitor - Electrolytic (Simple) built-in function.
The generic model ELEC_CAP_L13 used for the simple electrolytic capacitor is shown below:
Electrolytic Capacitor (Level 4-5)
These components have their Spice Type set to use the Capacitor - Electrolytic (Detailed) built-in function.
The generic model ELEC_CAP_L45 used for the detailed electrolytic capacitor is shown below:
Lossy Inductor
These components have their Spice Type set to use the Inductor - Lossy built-in function.
This is a simple linear inductor which includes both series and shunt losses. The model for this device, defined by a Spice Template, is shown below:
Parameterised Opamp
These components have their Spice Type set to use the Opamp - Parameterised built-in function.
| Parameter Label | Units | Description |
| Offset Voltage | V | Input voltage needed for zero output |
| Bias Current | A | Average of input currents when out = 0 |
| Offset Current | A | Difference between input currents when out = 0 |
| Open-loop gain | Vout/(Vin+ - Vin-) | |
| Gain-bandwidth | Hz | Gain x bandwidth product |
| Pos. Slew Rate | V/s | Slew rate for positive output transitions |
| Neg. Slew Rate | V/s | Slew rate for negative output transitions |
| CMRR | Common mode rejection ratio. Expressed as straight ratio - not in dB | |
| PSRR | Power supply rejection ratio. Expressed as straight ratio - not in dB | |
| Input Resistance | W | Differential input resistance |
| Output Res. | W | Series output resistance |
| Quiescent current (see note) | A | Quiescent current |
| Headroom Pos | V | Difference between Pos supply voltage and maximum output voltage |
| Headroom Neg | V | Difference between min output voltage and Neg supply voltage |
| Offset V. (Statistical) | V | Offset voltage for Monte Carlo analysis. |
Note: Quiescent current is a constant current and does not vary with supply voltage.
Peak To Peak Voltage Source
These components have their Spice Type set to use the Source - Voltage Peak To Peak built-in function.
This component uses the generic PP_SOURCE model.
Sine Wave Burst Voltage Source
These components have their Spice Type set to use the Source - Sine Tone Burst built-in function.
This component uses the generic SINEBURST model.
Sine Wave Sweep Voltage Source
These components have their Spice Type set to use the Source - Swept Sine built-in function.
This component uses the generic SINERAMP model.
Switch With Hysteresis
These components have their Spice Type set to use the Switch - With Hysteresis built-in function.
An alternative switch device which abruptly switches between states rather than following a continuous V-I characteristic. The switching thresholds are governed by an hysteresis law and the state change is controlled to occur over a fixed time period (currently 10nS).
Transmission Line (Lossless)
These components have their Spice Type set to use the Lossless Transmission Line device type.
Impedance
Type in the characteristic impedance (Z0).
Delay
Type in the line delay in seconds.
Tolerances
The relative and absolute tolerance parameters may be reduced to improve accuracy at the expense of speed.
Transmission Line (Lossy RLC)
These components have their Spice Type set to use the Transmission Line - Lossy RLC built-in function.
Lossy lines must be defined in terms of their per unit length impedance characteristics. Currently only series losses are supported.
Enter parameters as indicated. Relative and absolute tolerance values may be reduced to improve accuracy.
Watch Voltage, Watch Current and Watch Differential Voltage
These three components are used to perform simple SOA Limit tests. They have their Spice Type set to use the corresponding Watch built-in function.
See the Safe Operating Area help page for more information on editing these devices.
Related Topics
Edit Parameter | Edit Spice Type | Select Spice Model | Shift F7 | Show Spice Value