Sawtooth Waveform Load

The Sawtooth Waveform Load subcircuit models a repeating Sawtooth waveform load current with a duty cycle of 99.9%. In DVM, 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:

In this topic:

  DVM Information Power Supply (Non-DVM) Information
Model Name Sawtooth Waveform Load
Simulator
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
Power Supply Loads > Power Supply Load ( DC Current, Pulse, Bode, Zout... )
Symbol Library SIMPLIS_DVM_ADVANCED.sxslb power_supply_source_and_loads.sxslb
Model File SIMPLIS_DVM_ADVANCED.lb power_supply_source_and_loads.lb
Subcircuit Name
  • SIMPLIS_DVM_ADVANCED_LOAD_2T_SAW
  • SIMPLIS_DVM_ADVANCED_LOAD_3T_SAW
  • SIMPLIS_DVM_ADVANCED_LOAD_4T_SAW
POWER_SUPPLY_LOAD_SAW
Symbols
Schematic - 2 Terminal
Note: Power Supply probes will not have the "DVM" prefix.
Schematic - 3 Terminal
Note: Power Supply probes will not have the "DVM" prefix.
Schematic - 4 Terminal
Note: Power Supply probes will not have the "DVM" prefix.

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.

DVM 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 DVM Examples below. The order of the parameter names does not matter.

DVM Examples

The following examples set the first DVM managed load to a Sawtooth Load with a starting current of 1A and a final current of 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 pulse waveform begins with the START_CURRENT value of 0 at t=0.

*?@ Load
Saw(OUTPUT:1 , 1 , 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 50μs. Since the OFF_UNTIL_DELAY parameter is not specified, the TIME_DELAY is interpreted as a phase delay, meaning that the waveform is active from time=0.

*?@ Load
Saw(OUTPUT:1 , 1 , 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 50μs, and the OFF_UNTIL_DELAY is set to 1; therefore, for simulation times less than the TIME_DELAY parameter, the load current is 1A, which is the value of the START_CURRENT argument.

*?@ Load
Saw(OUTPUT:1 , 1 , 5 , 10k , OFF_UNTIL_DELAY=1 TIME_DELAY=50u)

The results of this testplan entry are shown below:

Phase Delay Example

In this example, the USE_PHASE parameter is set to 1, and the PHASE_ANGLE parameter is set to 60. Setting USE_PHASE to 1 configures the load to use the PHASE_ANGLE parameter to determine the effective time delay. The time delay is calculated by:

\[ \text{TIME_DELAY} = \frac{\text{PHASE_ANGLE}}{\text{360*FREQUENCY}} \]

*?@ Load
Saw(OUTPUT:1 , 1 , 5 , 10k , USE_PHASE=1 PHASE_ANGLE=60)

The results of this testplan entry are shown below:

Phase Delay Example With OFF_UNTIL_DELAY=1

In this example the PHASE_ANGLE parameter is set to 60, and the OFF_UNTIL_DELAY is set to 1; therefore, for simulation times less than the time delay defined by the PHASE_ANGLE parameter, the load current is 1A, which is the value of the START_CURRENT argument.

*?@ Load
Saw(OUTPUT:1 , 1 , 5 , 10k , OFF_UNTIL_DELAY=1 USE_PHASE=1 TIME_DELAY=50u PHASE_ANGLE=60)

The results of this testplan entry are shown below:

Converting between DVM and Power Supply Loads

To change a Power Supply load to a DVM load, right click the symbol to bring up the context menu, and select the menu option: Upgrade to DVM Source/Load

To change a DVM load to a Power Supply load, right click the symbol to bring up the context menu, and select the menu option: Downgrade to SIMetrix/SIMPLIS Source/Load