Ramp Input Source

The ramp input source applies a ramp or a step voltage to the input of the circuit under test. The rise time is controlled by the RISE_TIME parameter and the source includes probes for the source voltage and current. In DVM, this source is used in the StepLine() Test Objective.

Other similar sources include:

In this topic:

  DVM Information Power Supply (Non-DVM) Information
Model Name Ramp Input Source
Simulator
Parts Selector
Menu Location
DVM > Sources > DVM Input Source Power Supply Sources > Power Supply Source ( DC Voltage, Pulse, Ramp, Zin... )
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_SOURCE_RAMP POWER_SUPPLY_SOURCE_RAMP
Symbols
Schematic
Note: Power Supply probes will not have the "DVM" prefix.

Ramp Input Source Parameters

The following table explains the relevant parameters.

Parameter Name Default Data Type Range Units Parameter Description
FINAL_VOLTAGE 12 Real min: 0 V The final voltage for the source
RISE_TIME 100u Real min: 0 s The ramp rise time in seconds
SOURCE_NAME SRC String n/a n/a Name of the DVM source. This name cannot contain spaces.
SOURCE_RESISTANCE 0.4 Real min:0 Sets the source resistance of the source
START_VOLTAGE 5 Real min: 0 V The starting voltage for the source
TIME_DELAY 10u Real min: 0 s The time delay before the ramp initiates

DVM Testplan Entry

To set any managed DVM source to a Ramp Source subcircuit, place a Ramp() testplan entry in the Source column.

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

Ramp(REF, START_VOLTAGE, FINAL_VOLTAGE)
Ramp(REF, START_VOLTAGE, FINAL_VOLTAGE, OPTIONAL_PARAMETER_STRING)
Argument Range Description
REF n/a The actual reference designator of the DVM source or the more generic syntax of OUTPUT:n where n is an integer indicating a position in the list of DVM sources
START_VOLTAGE min: 0 The starting voltage for the source. This can be a numeric value or a symbolic value, such as a percentage of the nominal input voltage.
FINAL_VOLTAGE min: 0 The final voltage for the source. This can be a numeric value or a symbolic value, such as a percentage of the nominal input voltage.
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 StepLine() test, DVM sets the input to use the Ramp Source subcircuit. Then DVM sets the TIME_DELAY and RISE_TIME parameters for the Ramp Source. You can change the timing with the Ramp() function call by providing the timing parameters as an optional parameter string, which is the fourth argument to the Ramp() function call.

DVM Example

The following example sets the first DVM managed source to a Ramp Source, with a starting voltage of 1V and a final voltage of 5V. The optional parameter string in this example sets the time delay to 25us and the rise time to 100us.

Note: In this examples, the Source column is the first column in the testplan and, therefore, begins with the special three character sequence: *?@.
*?@ Source
Ramp(INPUT: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_VOLTAGE
Y1 FINAL_VOLTAGE

Converting between DVM and Power Supply Sources

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

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