Pulse Load - Single Current Pulse

The Pulse Load - Single Current Pulse subcircuit models a single pulse in parallel with a resistive load. At time=0, the load starts at the resistive load. The load pulse is determined by the pulse parameters. You can configure any managed DVM load to a Ramp Pure Load with a Pulse() function call in the Load column of your testplan.

This load is used in the following test objectives:

Other similar loads include the following:

In this topic:

Model Name Pulse Load - Single Current Pulse
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 Names
  • SIMPLIS_DVM_ADVANCED_LOAD_2T_PULSE
  • SIMPLIS_DVM_ADVANCED_LOAD_3T_PULSE
  • SIMPLIS_DVM_ADVANCED_LOAD_4T_PULSE
Symbols
Schematic - 2 Terminal

 

Schematic - 3 Terminal
Schematic - 4 Terminal

Parameters

The table below explains the parameters used in the Pulse Load - Single Current Pulse subcircuit.

Parameter Name Default Data Type Range Units Parameter Description
FALL_TIME 50u Real min: 0 s The pulse fall time in seconds
FINAL_CURRENT 750m Real min: 0 A The final current for the PWL current source portion of the load. The Pulse Load - Single Current Pulse continues at this current for all simulation times greater than TIME_DELAY + RISE_TIME. This can be a numeric value or a symbolic value, such as a percentage of full load.
LOAD_NAME LOAD String n/a n/a Name of the DVM load. This name cannot contain spaces.
LOAD_RESISTANCE 2.00667 Real min: 0 Ω The resistance value which models the starting current of the load
PULSE_CURRENT 250m Real min: 0 A The pulsed current in amps. The pulse current can be a numeric value or a symbolic value, such as a percentage of full load.
PULSE_WIDTH 200u Real min: 0 s The pulse width in seconds.

DVM considers the pulse width to be the duration of the pulse at the PULSE_CURRENT.

RISE_TIME 100u Real min: 0 s The pulse rise time in seconds
START_CURRENT 0 Real min: 0 A The starting current for the PWL current source portion of the load. This is typically set to 0 since the minimum load current is modeled with the LOAD_RESISTANCE parameter.
TIME_DELAY 10u Real min: 0 s The time delay before the pulse initiates

Testplan Entry

To set any managed DVM load to a Pulse Load - Single Current Pulse subcircuit, place a Pulse() testplan entry in the Load column.

The Pulse() testplan entry has the following syntax with the arguments explained in the table below.

Pulse(REF, ISTART, IPULSE, IFINAL)
Pulse(REF, ISTART, IPULSE, IFINAL, OPTIONAL_PARAMETER_STRING)

where:

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 DVM loads
ISTART min: 0 The starting current for the load. In the Pulse load, the starting current is modeled with a resistor. This can be a numeric value or a symbolic value, such as a percentage of full load.
IFINAL min: 0 The final current for the load. This can be a numeric value or a symbolic value, such as a percentage of full load.
OPTIONAL_PARAMETER_STRING n/a

Parameter string with a combination of one or more timing parameters:

  • TIME_DELAY*
  • RISE_TIME*
  • FALL_TIME*
  • PULSE_WIDTH*

*    If more than one parameter is specified, join the parameter key-value pairs with a space, as shown in the example below. The order of the parameter names does not matter.

DVM calculates the LOAD_RESISTANCE parameter from the ???MATH???I_{START}???MATH??? argument and subtracts the equivalent starting current from the PWL portion of the load. The calculation for the LOAD_RESISTANCE parameter is based on the following:

  • The nominal output voltage which is entered in the Output page of the Full Power Assist Control Symbol.
  • The starting load current given in the Pulse() function or the PulseLoad() objective.
Note: If the specified starting current is 0 and the load is configured by DVM using either a Pulse() function or the PulseLoad() test objective, DVM replaces the Pulse Load - Single Current Pulse subcircuit with a Pulse Load - Single Pure Current Pulse subcircuit. The Pulse Load - Single Current Pulse does not use a parallel resistance to model the starting current.

Timing

DVM sets the timing of the Pulse Load - Single Current Pulse in the PulseLoad() test objective. You can change the timing with a Pulse() function call by providing the timing parameters as an optional parameter string, which is the fifth argument to the Pulse() function call.

Symmetric Pulse Example

This example shows a symmetric pulse with equal rise and fall times. The final current is the same as the starting current.

Note: In this example, the Load column is the first column in the testplan and, therefore, begins with the special three character sequence: *?@.
*?@ Load
Pulse(OUTPUT:1, 1, 5, 1, TIME_DELAY=25u RISE_TIME=25u PULSE_WIDTH=100u FALL_TIME=25u)

The results of this testplan entry are shown below:

Annotation Value
X0 TIME_DELAY
X1 TIME_DELAY + RISE_TIME
X2 TIME_DELAY + RISE_TIME + PULSE_WIDTH
X3 TIME_DELAY + RISE_TIME + PULSE_WIDTH + FALL_TIME
Y0 ISTART (see note below)
Y1 IPULSE (see note below)
Y2 IPULSE (see note below)
Y3 IFINAL (see note below)
Note: The actual load current depends on the LOAD_RESISTANCE parameter and the actual time-varying load voltage. The ???MATH???I_{START}???MATH??? current is modeled by a resistor defined by the LOAD_RESISTANCE parameter in the pulse load subcircuit. The PWL current source has points defined by the ramp-load START_CURRENT, PULSE_CURRENT, and FINAL_CURRENT parameter values.

Asymmetric Pulse Example

The following example sets the first DVM managed load to a Pulse Load - Single Current Pulse with a starting current of 1A, a pulse current of 5A, and a final current of 4.5A.

Note: The rise and fall times are not the same and the pulse does not have to return to the starting current value.
*?@ Load
Pulse(OUTPUT:1, 1, 5, 4.5, TIME_DELAY=25u RISE_TIME=25u PULSE_WIDTH=75u FALL_TIME=50u)

The results of this testplan entry are shown below:

Annotation Value
X0 TIME_DELAY
X1 TIME_DELAY + RISE_TIME
X2 TIME_DELAY + RISE_TIME + PULSE_WIDTH
X3 TIME_DELAY + RISE_TIME + PULSE_WIDTH + FALL_TIME
Y0 ISTART (see note below)
Y1 IPULSE (see note below)
Y2 IPULSE (see note below)
Y3 IFINAL (see note below)
Note: The actual load current depends on the LOAD_RESISTANCE parameter and the actual time-varying load voltage. The ???MATH???I_{START}???MATH??? current is modeled by a resistor with resistance LOAD_RESISTANCE, while the PWL current source has points defined by the START_CURRENT and FINAL_CURRENT parameter values.