SteadyState Test Objective

The purpose of the SteadyState test is to measure the steady-state operating point of the converter. During a SteadyState test, the input is configured as a DC Input Source, and the output is configured as a Resistive Load, and a Periodic Operating Point simulation is run. Since the test objective does not specify the input voltage nor the output current, you must provide these values in the Source and Load columns in the testplan.

Only a POP analysis is used in the SteadyState test with the directives taken from the POP Analysis tab, which is shown below and accessed from the Full Power Assist DVM control symbol.

The test report includes frequency, source, and load graphs as well as the following scalar values which are defined in the Measured Scalar Values section below:

  • Efficiency
  • Power({load_name})
  • Power({source_name})
  • sw_freq

In this topic:

Testplan Syntax

The SteadyState objective has no arguments. In the Objective column of the testplan, you simply enter:

SteadyState
SteadyState( OPTIONAL_PARAMETER_STRING )
Argument Range Description
OPTIONAL_PARAMETER_STRING n/a Parameter string with a combination of one or more parameters:
*    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.

Source and Load Subcircuit Configuration

The SteadyState test objective sets the source and load subcircuits to the following:

Source Load
DC Input Source Resistive Load

Loads other than the output under test are set to the Resistive Load. All other sources are set to the DC Input Source.

Measured Scalar Values

The SteadyState test objective measures the following scalar values,where {load_name} and {src_name} are replaced by the actual load name source name:

Scalar Name Description
Efficiency The overall efficiency of the converter taken from the POP simulation
Power({load_name) The power of each input source taken from the POP simulation
Power({load_name}) The power of each output load taken from the POP simulation
sw_freq A number which represents the converter switching frequency. This scalar is generated from a fixed probe with curve label DVM Frequency. For more information, see Measuring the Switching Frequency.
AVG(V{load_name}) AVG(I{load_name})
MIN(V{load_name}) MIN(I{load_name})
MAX(V{load_name}) MAX(I{load_name})
RMS(V{load_name}) RMS(I{load_name})
PK2PK(V{load_name}) PK2PK(I{load_name})
The Average, Minimum, Maximum, RMS and Peak-to-Peak values for each load voltage and current taken over the entire simulation time window.
AVG(V{src_name}) AVG(I{src_name})
MIN(V{src_name}) MIN(I{src_name})
MAX(V{src_name}) MAX(I{src_name})
RMS(V{src_name}) RMS(I{src_name})
PK2PK(V{src_name}) PK2PK(I{src_name})
The Average, Minimum, Maximum, RMS and Peak-to-Peak values for each source voltage and current taken over the entire simulation time window.

Measured Specification Values

In the following table, {load_name} is the name assigned to each load. The default value is LOAD. DVM forces each load name to be unique so that the scalar and specification values for each load are unique.

Specification Name PASS/FAIL Criteria
Min_V{load_name} The minimum value of the output voltage during the simulation time is greater that the minimum specification value.
Max_V{load_name} The maximum value of the output during the simulation time is less than the maximum specification value.

Testplan Example

The SteadyState test objective is used in several built-in testplans. Shown below is a test from the DC/DC 1 input/1 output testplan.  The source and load are defined in the Full Power Assist DVM control symbol. The test configures the source to use the Nominal symbolic value from the AC Input page and configures the load based on the Light symbolic value from the Output page.

*?@ Analysis Objective Source Load Label
Steady-State SteadyState SOURCE(INPUT:1, Nominal) LOAD(OUTPUT:1, Light) Steady-State|Steady-State|Vin Nominal|Light Load

Test Report

You can view the complete test report in a new browser window here: SteadyState Test Report. Below is an interactive link to the same test report.