DVM - Design Verification Module

Cosine Waveform Load

The Cosine Waveform Load subcircuit models a time-varying load with a cosinusoidal current. At time=0, the load begins at the FINAL_CURRENT value and has a cosine function. The Cosine Waveform Load is not used in any test objectives, but you can change any load to a cosine load with a Cos() function call in a Load column.

Other similar loads include:

Sine Load - similar to the Cosine Waveform Load but with a sine function.

In this Topic ShowHide

Parameters
Testplan Entry
Examples

Model Name	Cosine 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_COS SIMPLIS_DVM_ADVANCED_LOAD_3T_COS SIMPLIS_DVM_ADVANCED_LOAD_4T_COS
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
COEFFICIENT	0	Real			The damping coefficient for the cosinusoidal load current. If non-zero, the cosinusoidal load current amplitude will decay with a time constant equal to $\frac{1}{\text{COEFFICIENT}}$.
FINAL_CURRENT	750m	Real		A	The peak or maximum current for the load. 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 cosine waveform load
IDLE_IN_POP	0	Real	0 or 1		If set to 0, the load current during the POP analysis is set to the FINAL_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 $\frac{1}{2}\left(\text{START_CURRENT}+\text{FINAL_CURRENT}\right)$ 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 cosinusoidal waveform, used only if the USE_PHASE parameter is 1.
START_CURRENT	0	Real		A	The minimum or starting current for the cosine waveform load. 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 cosinusoid 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 Cosine Waveform Load subcircuit, place a Cos() testplan entry in a Load column.

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

Cos(REF, START_CURRENT, FINAL_CURRENT, FREQUENCY)
Cos(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 minimum or starting current for the cosine waveform load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FINAL_CURRENT	n/a	The peak or maximum current for the cosine wave load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FREQUENCY	min: > 0	The frequency of the cosine waveform 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 three examples set the first DVM managed load to a Cosine Waveform Load with a minimum current of 0A and a peak current of 1A. The timing parameters and the optional parameter strings are different in each example.

Note: In all of the examples below, the Load column is the first column in the testplan and, therefore, begins with the special three character sequence: *?@.

Zero Time Delay Example

Since the TIME_DELAY parameter is set to zero in this example, the cosine wave begins with the FINAL_CURRENT value of 1A at t=0.

*?@ Load
Cos(OUTPUT:1, 0, 1, 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 25us. Since the OFF_UNTIL_DELAY parameter is not specified, the TIME_DELAY value is interpreted as a phase delay. This results in the same waveform as a Sine Waveform Load.

*?@ Load
Cos(OUTPUT:1, 0, 1, 10k, TIME_DELAY=25u)

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 25us, and the OFF_UNTIL_DELAY is set to 1; therefore, for simulation times less than the TIME_DELAY parameter, the load current is 0.5A, as determined by the following equation:
$\frac{1}{2}\left(\text{START_CURRENT}+\text{FINAL_CURRENT}\right)$

*?@ Load
Cos(OUTPUT:1, 0, 1, 10k, TIME_DELAY=25u OFF_UNTIL_DELAY=1)

The results of this testplan entry are shown below: