Pulse Load - Single Current Pulse w/ Exponential Decay

The Pulse Load - Single Current Pulse w/ Exponential Decay subcircuit models a single exponential decaying pulse current load. This load is not used in any test objectives, but you can set a load to use this subcircuit with an Exp() call in the Load column of your testplan.

Other similar loads include:

In this topic:

Model Name Exponential Decay Pulse Current 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_EXP
  • SIMPLIS_DVM_ADVANCED_LOAD_3T_EXP
  • SIMPLIS_DVM_ADVANCED_LOAD_4T_EXP
Symbols
Schematic - 2 Terminal
Schematic - 3 Terminal
Schematic - 4 Terminal

Pulse Load - Single Current Pulse w/ Exponential Decay Parameters

The following table explains the relevant parameters for the Single Current Pulse w/ Exponential Decay Load.

Note: This load is different than the other loads in that the RISE_TIME and FALL_TIME parameters are interpreted as time constants, as opposed to literal rise and fall times. These two parameters are highlighted in red text in the table below.
Parameter Name Default Data Type Range Units Parameter Description
FALL_TIME 50u Real min: 0 s The time constant of the falling edge of the pulse in seconds
FINAL_CURRENT 750m Real min: 0 A The pulse current for the load. This can be a numeric value or a symbolic value, such as a percentage of full load.
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.
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 time constant of the rising edge of the pulse in seconds
START_CURRENT 0 Real min: 0 A The starting current for the 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 time delay before the pulse initiates

Testplan Entry for the Single Current Pulse w/ Exponential Decay

To set any managed DVM load to a Single Current Pulse w/ Exponential Decay subcircuit, place an Exp() testplan entry in the Load column.

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

Exp(REF, START_CURRENT, FINAL_CURRENT, TIME_DELAY, RISING_TAU, PULSE_WIDTH, FALLING_TAU)
Exp(REF, START_CURRENT, FINAL_CURRENT, TIME_DELAY, RISING_TAU, PULSE_WIDTH, FALLING_TAU, 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. 
START_CURRENT min: 0 The starting current for the load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FINAL_CURRENT min: 0 The pulse current for the load. This can be a numeric value or a symbolic value, such as a percentage of full load.
TIME_DELAY min: 0 The delay before the rising edge of the Exponential Pulse. The model TIME_DELAY parameter is set to this time value.
RISING_TAU min: 0 The time constant for the rising edge of the Exponential Pulse. The model RISE_TIME parameter is set to this time value.
PULSE_WIDTH min: 0 The pulse width of the Exponential Pulse, including the exponential rising edge
FALLING_TAU min: 0 The time constant for the falling edge of the Exponential Pulse. The model FALL_TIME parameter is set to this time value.
OPTIONAL_PARAMETER_STRING n/a Parameter string with any of the other parameters from the parameter table above*
*    If more than one parameter is specified, join the parameter key-value pairs with a space, for example:
parameter_name1=parameter_value1 parameter_name2=parameter_value2
The order of the parameter key-value pairs does not matter.

Symmetric Rising and Falling Edge Tau Example

The following example sets the first DVM managed load to a Single Current Pulse w/ Exponential Decay load with a starting current of 1A and a pulse current of 5A. This example shows a pulse with symmetric rising and falling edge time constants.

Note: In the following testplans, the Load column is prefaced with the characters *?@ because it is the first column in the testplan.
*?@ Load
Exp(OUTPUT:1, 1, 5, 25u, 3u, 150u, 3u)

The results of this testplan entry are shown below:

Asymmetric Rising and Falling Edge Tau Example

The following example sets the first DVM managed load to a Single Current Pulse w/ Exponential Decay load with a starting current of 1A and a pulse current of 5A. This example shows a pulse with asymmetric rising and falling edge time constants. The rising edge time constant is 3us, and the falling edge time constant is 1us.

Note: In the following testplans, the Load column is prefaced with the characters *?@ because it is the first column in the testplan.
*?@ Load
Exp(OUTPUT:1, 1, 5, 25u, 3u, 150u, 1u)

The results of this testplan entry are shown below:

Collected links
Load
Pulse Load - Single Current Pulse
Pulse Load - Single Pure Current Pulse
Symbolic Values
Managed Sources and Loads