DVM - Design Verification Module

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 ShowHide

Parameters
Testplan Entry
Examples

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 DVM 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 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 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.

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: