ConductedSusceptibility() Test Objective
The purpose of the ConductedSusceptibility() test is to determine the converter's ability to reject a small-signal perturbation at the input. To measure this susceptibility, DVM automatically connects a special susceptibility probe between the input source and each managed DVM load. The input is configured as a DC Input Susceptibility Source, and the output is configured as a Resistive Load.
Both a POP and an AC analysis are used in the ConductedSusceptibility() test.
- The POP simulation finds the large-signal steady-state operating point of the converter at the particular input and output voltage.
- The AC simulation perturbs the circuit in a small-signal manner around the large-signal steady-state operating point; measures the minimum and maximum magnitudes and the frequencies where these occur and measures the phase of the input rejection(???MATH???V_{OUT}???MATH???/???MATH???V_{IN}???MATH???).
The POP and AC analysis directives are taken from the POP Analysis page and the AC Analysis page of the Full Power Assist DVM control symbol. The AC Analysis page is shown below.
The test report includes source, load, and susceptibility graphs as well as the following scalar values which are defined in the Measured Scalar Values section below:
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In this topic:
Susceptibility Probe
The susceptibility probe includes an AC probe and two voltage-controlled sources to galvanically isolate the input and output from ground.
Testplan Syntax
The ConductedSusceptibility() function has the following syntax with the argument described in the table below:
ConductedSusceptibility(REF) ConductedSusceptibility(REF, OPTIONAL_PARAMETER_STRING)
| Argument | Range | Description |
| REF | n/a | The actual reference designator of the DVM source or the generic syntax of INPUT:n where n is an integer indicating a position in the list of DVM sources. |
| OPTIONAL_PARAMETER_STRING | n/a | Parameter string with a combination of one or more parameters: |
parameter_name1=parameter_value1 parameter_name2=parameter_value2The order of the parameter key-value pairs does not matter.
Source and Load Subcircuit Configuration
The ConductedSusceptibility() test objective sets the source and load subcircuits to the following:
| Source | Load |
| DC Input Susceptibility 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 ConductedSusceptibility() test objective measures the following scalar values:
| Scalar Name | Description | ||||||||||
| Efficiency | The overall efficiency of the converter taken from the POP simulation | ||||||||||
| Power(LOAD{load_name) | The power of each input source taken from the POP simulation | ||||||||||
| Power(SRC{load_name}) | The power of each output load taken from the POP simulation | ||||||||||
| min_reject1_gain | The minimum value for the gain during the AC analysis | ||||||||||
| max_reject1_gain | The maximum value for the gain during the AC analysis | ||||||||||
| min_reject1_gain_freq | The frequency where the gain is at its minimum value | ||||||||||
| max_reject1_gain_freq | The frequency where the gain is at its maximum value | ||||||||||
| min_reject1_phase | The minimum value for the phase during the AC analysis | ||||||||||
| max_reject1_phase | The maximum value for the phase during the AC analysis | ||||||||||
| min_reject1_phase_freq | The frequency where the phase is at its minimum value | ||||||||||
| max_reject1_phase_freq | The frequency where the phase is at its maximum value | ||||||||||
| 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. | ||||||||||
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The Average, Minimum, Maximum, RMS and Peak-to-Peak values for each load voltage and current taken over the entire simulation time window. | ||||||||||
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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 ConductedSusceptibility() test objective is used in several built-in testplans. The managed source and load designators INPUT:1 and OUTPUT:1 are defined in the Full Power Assist DVM control symbol. The tests configures the source to use the Nominal symbolic value from the DC Input page and configures the load to the Light symbolic value from the Output page.
| *?@ Analysis | Objective | Source | Load | Label |
| Ac | ConductedSusceptibility(INPUT:1) | SOURCE(INPUT:1, Nominal) | LOAD(OUTPUT:1, Light) | Ac Analysis|Conducted Susceptibility|Vin Nominal|Light Load |
Optional Parameter String
The following ConductedSusceptibility() test objective uses the OPTIONAL_PARAMETER_STRING argument to instruct DVM to not to set the analysis directive when processing the ConductedSusceptibility() objective entry. You can set an analysis directive with an Analysis entry. The analysis entry should specify a POP and AC analysis. The OVERWRITE_ANALYSIS parameter allows you to explicitly specify the analysis directives.
ConductedSusceptibility(INPUT:1, OVERWRITE_ANALYSIS=0)
Test Report
You can view the complete test report in a new browser window here: ConductedSusceptibility() Test Report. Below is an interactive link to the same test report.