Sawtooth Waveform Source
The Sawtooth Waveform Source subcircuit models a repeating Sawtooth waveform source with a duty cycle of 99.9%. This source is not used in any test objectives, but you can set a source to use this subcircuit with a Saw() call in the Source column of your testplan.
Other similar sources include:
- Square Waveform Source - a 50% duty cycle square wave source
- Triangle Waveform Source - a triangular waveform with configurable duty cycle
In this topic:
| Model Name | Sawtooth Waveform Source | |
| Simulator |
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This device is compatible with both the SIMetrix and SIMPLIS simulators. |
| Parts Selector Menu Location |
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| Symbol Library | None - the symbol is automatically generated when placed or edited. | |
| Model File | SIMPLIS_DVM_ADVANCED.lb | |
| Subcircuit Name | SIMPLIS_DVM_ADVANCED_SOURCE_SAW | |
| Symbols |
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| Schematic - 2 Terminal |
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Parameters
The following table explains the relevant parameters.
| Parameter Name | Default | Data Type | Range | Units | Parameter Description |
| FINAL_VOLTAGE | 750m | Real | V | The peak or final voltage for the sawtooth source voltage. This can be a numeric value or a symbolic value, such as a percentage of nominal input voltage. | |
| FREQUENCY | 10k | Real | min: > 0 | Hz | The frequency of the source pulse |
| IDLE_IN_POP | 0 | Real | 0 or 1 | If set to 0, the source voltage during the POP analysis is set to the START_VOLTAGE; otherwise the source will be active during the POP analysis. | |
| SOURCE_NAME | SRC | String | n/a | n/a | Name of the DVM source. This name cannot contain spaces. |
| OFF_UNTIL_DELAY | 0 | Real | 0 or 1 | If set to 1, the source voltage will be the START_VOLTAGE until the time specified by TIME_DELAY. If set to 0, the value of TIME_DELAY is interpreted as a phase delay. | |
| PHASE_ANGLE | 90 | Real | ° | The phase angle of the sawtooth waveform, used only if the USE_PHASE parameter is 1. | |
| START_VOLTAGE | 0 | Real | V | The valley or starting voltage for the sawtooth source voltage. This can be a numeric value or a symbolic value, such as a percentage of nominal input voltage. | |
| TIME_DELAY | 10u | Real | min: 0 | s | The delay before the source voltage pulse starts. The source behavior before the TIME_DELAY is determined by the OFF_UNTIL_DELAY parameter. |
| USE_PHASE | 0 | Real | 0 or 1 | If set to 1, the source is configured to use the phase angle supplied by the PHASE_ANGLE parameter. |
Testplan Entry
To set any managed DVM source to a Sawtooth Source subcircuit, place a Saw() testplan entry in the Source column.
The Saw() testplan entry has the following syntax with the arguments taken from the list of Parameters above.
Saw(REF, START_VOLTAGE, FINAL_VOLTAGE, FREQUENCY) Saw(REF, START_VOLTAGE, FINAL_VOLTAGE, FREQUENCY, OPTIONAL_PARAMETER_STRING)
| Argument | Range | Description |
| REF | n/a | The actual reference designator of the DVM source or the more generic syntax of INPUT:n where n is an integer indicating a position in the list of DVM sources. |
| START_VOLTAGE | n/a | The valley or starting voltage for the sawtooth source voltage. This can be a numeric value or a symbolic value, such as a percentage of nominal input voltage. |
| FINAL_VOLTAGE | n/a | The peak or final voltage for the sawtooth source voltage. This can be a numeric value or a symbolic value, such as a percentage of nominal input voltage. |
| FREQUENCY | min: > 0 | The frequency of the sawtooth source |
| OPTIONAL_PARAMETER_STRING | n/a | Parameter string with any of the other parameters from the parameter table above* |
* If multiple parameters are specified, join the parameter key-value pairs with a space, as shown in the examples below. The order of the parameter names does not matter.
Examples
The following examples set the first DVM managed source to a Sawtooth Source with a starting voltage of 0V and a final voltage of 2.5V. The timing parameters and the optional parameter strings are different for each example.
Zero Time Delay Example
Since the TIME_DELAY parameter is set to zero, the triangle wave begins with a START_VOLTAGE value of 0 at t=0.
| *?@ Source |
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| Saw(INPUT:1, 0, 2.5, 10k, TIME_DELAY=0) |
The results of this testplan entry are shown below:
Time Delay Example
In this example, the TIME_DELAY parameter is set to 50us. Since the OFF_UNTIL_DELAY parameter is not specified, the TIME_DELAY is interpreted as a phase delay.
| *?@ Source |
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| Saw(INPUT:1, 0, 2.5, 10k, TIME_DELAY=50u) |
The results of this testplan entry are shown below:
Time Delay Example With OFF_UNTIL_DELAY=1
In this example, the TIME_DELAY parameter is set to 50us, and the OFF_UNTIL_DELAY is set to 1; therefore, for simulation times less than the TIME_DELAY parameter, the source voltage is 0V, which is the value of the START_VOLTAGE argument.
| *?@ Source |
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| Saw(INPUT:1, 0, 2.5, 10k, TIME_DELAY=50u OFF_UNTIL_DELAY=1) |
The results of this testplan entry are shown below:
