DVM - Design Verification Module

Ramp Pure Load

The Ramp Pure Load subcircuit models a single ramped or stepped load current using a PWL current source. The Ramp Pure Load subcircuit is not used in any test objectives. You can configure any managed DVM load to a Ramp Pure Load with a RampPure() function call in the testplan Load column.

Other similar loads include the following:

Ramp Load - a ramped load where the starting current is modeled with a resistor and the ramp current is modeled with a PWL current source
Pulse Load - Single Current Pulse - a single current pulse load with the starting current modeled with a resistor
Pulse Load - Single Pure Current Pulse - a single current pulse load with the starting current modeled without a resistor

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Parameters
Testplan Entry
Timing
Example

Model Name	Ramp Pure 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 Names	SIMPLIS_DVM_ADVANCED_LOAD_2T_RAMP_PURE SIMPLIS_DVM_ADVANCED_LOAD_3T_RAMP_PURE SIMPLIS_DVM_ADVANCED_LOAD_4T_RAMP_PURE
Symbols
Schematic - 2 Terminal
Schematic - 3 Terminal
Schematic - 4 Terminal

Parameters

DVM uses the parameter values passed into the RampPure() function and does not perform calculations as it does for the Ramp Load function.

The table below explains the parameters used in the Ramp Pure Load subcircuit.

Parameter Name	Default	Data Type	Range	Units	Parameter Description
FINAL_CURRENT	750m	Real	min: 0	A	The final current for the load. The Ramp Pure Load continues at this current for all simulation times greater than TIME_DELAY + RISE_TIME.
LOAD_NAME	LOAD	String	n/a	n/a	Name of the DVM load. This name cannot contain spaces.
RISE_TIME	100u	Real	min: 0	s	The ramp rise time in seconds
START_CURRENT	0	Real	min: 0	A	The starting current for the load
TIME_DELAY	10u	Real	min: 0	s	The time delay before the ramp initiates

Testplan Entry

To set any managed DVM load to a Ramp Pure Load subcircuit, place a RampPure() testplan entry in the Load column.

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

RampPure(REF, START_CURRENT, FINAL_CURRENT)
RampPure(REF, START_CURRENT, FINAL_CURRENT, 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	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 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 timing parameters TIME_DELAY and/or RISE_TIME*

* If both parameters are specified, join the two parameter key-value pairs with a space, as shown in the example below. The order of the parameter names does not matter.

Timing

During a StepLoad() test, DVM sets the output under test to use the Ramp Pure Load subcircuit. Then DVM sets the TIME_DELAY and RISE_TIME parameters for the Ramp Load. You can change the timing with the RampPure() function call by providing the timing parameters as an optional parameter string, which is the fourth argument to the RampPure () function call.

Example

The following example sets the first DVM managed load to a Ramp Pure Load, with a starting current of 1A and a final current of 5A. The optional parameter string in this example sets the time delay to 25us and the rise time to 100us.

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

*?@ Load
RampPure(OUTPUT:1, 1, 5, TIME_DELAY=25u RISE_TIME=100u)

The results of this testplan entry are shown below:

Annotation	Parameter Value
X0	TIME_DELAY
X1	TIME_DELAY + RISE_TIME
Y0	START_CURRENT
Y1	FINAL_CURRENT