Sawtooth Waveform Load

The Sawtooth Waveform Load subcircuit models a repeating Sawtooth waveform load current with a duty cycle of 99.9%. This load is not used in any test objectives, but you can set a load to use this subcircuit with a Saw() call in the Load column of your testplan.

Other similar loads include:

Square Waveform Load - a 50% duty cycle square wave load
Triangle Waveform Load - a triangular waveform with configurable duty cycle

In this topic:

Model Name

Sawtooth Waveform Load

Simulator

This device is compatible with both the SIMetrix and SIMPLIS simulators.

Parts Selector
Menu Location

DVM > Loads > DVM Output Load - 2 Terminal
DVM > Loads > DVM Output Load - 3 Terminal
DVM > Loads > DVM Output Load - 4 Terminal

Symbol Library

None - the symbol is automatically generated when placed or edited.

Model File

SIMPLIS_DVM_ADVANCED.lb

Subcircuit Name

SIMPLIS_DVM_ADVANCED_LOAD_2T_SAW
SIMPLIS_DVM_ADVANCED_LOAD_3T_SAW
SIMPLIS_DVM_ADVANCED_LOAD_4T_SAW

Symbols

Schematic - 2 Terminal

Schematic - 3 Terminal

Schematic - 4 Terminal

Parameters

The following table explains the relevant parameters.

Parameter Name	Default	Data Type	Range	Units	Parameter Description
FINAL_CURRENT	750m	Real		A	The peak or final current for the sawtooth load current. This can be a numeric value or a symbolic value, such as a percentage of full load.
FREQUENCY	10k	Real	min: > 0	Hz	The frequency of the load pulse
IDLE_IN_POP	0	Real	0 or 1		If set to 0, the load current during the POP analysis is set to the START_CURRENT; otherwise the load will be active during the POP analysis.
LOAD_NAME	LOAD	String	n/a	n/a	Name of the DVM load. This name cannot contain spaces.
OFF_UNTIL_DELAY	0	Real	0 or 1		If set to 1, the load current will be the START_CURRENT 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_CURRENT	0	Real		A	The valley or starting current for the sawtooth load current. This can be a numeric value or a symbolic value, such as a percentage of full load.
TIME_DELAY	10u	Real	min: 0	s	The delay before the load current pulse starts. The load 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 load is configured to use the phase angle supplied by the PHASE_ANGLE parameter.

Testplan Entry

To set any managed DVM load to a Sawtooth Load subcircuit, place a Saw() testplan entry in the Load column.

The Saw() testplan entry has the following syntax with the arguments taken from the list of Parameters above.

Saw(REF, START_CURRENT, FINAL_CURRENT, FREQUENCY)
Saw(REF, START_CURRENT, FINAL_CURRENT, FREQUENCY, OPTIONAL_PARAMETER_STRING)

Argument	Range	Description
REF	n/a	The actual reference designator of the DVM load or the more generic syntax of OUTPUT:`n` where `n` is an integer indicating a position in the list of Managed Sources and Loads.
START_CURRENT	n/a	The valley or starting current for the sawtooth load current. This can be a numeric value or a symbolic value, such as a percentage of full load.
FINAL_CURRENT	n/a	The peak or final current for the sawtooth load current. This can be a numeric value or a symbolic value, such as a percentage of full load.
FREQUENCY	min: > 0	The frequency of the sawtooth load
OPTIONAL_PARAMETER_STRING	n/a	Parameter string with any of the other parameters from the Parameters 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 load to a Sawtooth Load with a starting current of 0A and a final current of 2.5A. The timing parameters and the optional parameter strings are different for each example.

Note: In the following testplans, the Load column is prefaced with the characters *?@ because it is the first column in the testplan.

Zero Time Delay Example

Since the TIME_DELAY parameter is set to zero, the triangle wave begins with a START_CURRENT value of 0 at t=0.

*?@ Load
Saw(OUTPUT: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.

*?@ Load
Saw(OUTPUT: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 load current is 0A, which is the value of the START_CURRENT argument.

*?@ Load
Saw(OUTPUT:1, 0, 2.5, 10k, TIME_DELAY=50u OFF_UNTIL_DELAY=1)

The results of this testplan entry are shown below: