PulseLine() Test Objective

The PulseLine() test objective uses a Pulse Input Source - Single Pulse and configures the output as a Resistive Load. The input source is configured with the starting, pulse and final voltage values that are passed as arguments to the PulseLine() test objective function.

The PulseLine() test objective runs both a POP and transient simulation on the converter.

The POP simulation finds the steady-state operating point of the converter at the starting voltage.
The transient simulation starts with the initial conditions found during the POP simulation. The timing for the transient simulation is determined by the values entered in the Step/Pulse Line page, which is shown below and accessed from the Full Power Assist DVM control symbol.

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

Switching frequency
Output voltage recovery times
Overshoot and Undershoot voltages.

In this topic:

Testplan Syntax

The PulseLine() function has the following syntax with the arguments described in the table below:

PulseLine(REF, START_VOLTAGE, PULSE_VOLTAGE, FINAL_VOLTAGE)
PulseLine(REF, START_VOLTAGE, FINAL_VOLTAGE, FINAL_VOLTAGE, 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.
START_VOLTAGE		The starting source voltage. The starting voltage can be a numeric value or a symbolic value, such as "Maximum."
PULSE_VOLTAGE		The pulse voltage. The pulse voltage can be a numeric value or a symbolic value, such as "Maximum."
FINAL_VOLTAGE		The final source voltage,.The final voltage can be a numeric value or a symbolic value, such as "Maximum."
OPTIONAL_PARAMETER_STRING	n/a	Parameter string with a combination of one or more timing parameters: TIME_DELAY* RISE_TIME* PULSE_WIDTH* FALL_TIME* CYCLES_TO_RECOVER* OVERWRITE_ANALYSIS* RESET_TO_STEADY_STATE*

* 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.

Timing

DVM sets the timing parameters for the StepLoad() test objective based on values that you enter on the following two tabs in the DVM Full Power Assist control symbol:

Step/Pulse Line page: Cycles Before Event, Pulse Line Duration, Cycles to Recover, and Slew Rate
Circuit Specifications page: Switching Frequency

The time delay, rise time, pulse width, fall time, and simulation stop time are determined by these calculations:

\[ \text{TIME_DELAY} = \frac{\text{CYCLES_BEFORE_EVENT}}{\text{SWITCHING_FREQUENCY}} \]

\[ \text{RISE_TIME} = \frac{ abs \left( \text{FINAL_VOLTAGE}-\text{START_VOLTAGE} \right)}{\text{SLEW_RATE}} \]

\[ \text{PULSE_WIDTH} = \frac{\text{PULSE_LINE_DURATION}}{\text{SWITCHING_FREQUENCY}} \]

\[ \text{FALL_TIME} = \frac{ abs \left( \text{PULSE_VOLTAGE}-\text{FINAL_VOLTAGE} \right)}{\text{SLEW_RATE}} \]

DVM then calculates the simulation stop time as follows:

\[ \text{STOP_TIME} = \text{TIME_DELAY} + \text{RISE_TIME} + \text{PULSE_WIDTH} + \text{FALL_TIME} + \frac{\text{CYCLES_TO_RECOVER}}{\text{SWITCHING_FREQUENCY}}\]

Note: The switching frequency and cycles to recover parameters are not the actual measured values from a simulation; they are constant values taken from the DVM control symbol. Also, you can override time delay, rise time, and cycles to recover on a test-by-test basis by using the optional parameter string.

Annotation	Value
X0	TIME_DELAY
X1	TIME_DELAY + RISE_TIME
X2	TIME_DELAY + RISE_TIME + PULSE_WIDTH
X3	TIME_DELAY + RISE_TIME + PULSE_WIDTH + FALL_TIME
Y0	START_VOLTAGE
Y1	PULSE_VOLTAGE
Y2	PULSE_VOLTAGE
Y3	FINAL_VOLTAGE

Source and Load Subcircuit Configuration

The PulseLine() test objective sets the source and load subcircuits to the following:

Source	Load
Pulse 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 PulseLine() 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

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.

vout{n}_recovery_time

The number {n} in the scalar name is an integer indicating a position in the list of Managed Sources and Loads. The three possible return values are the following:

A number which represents the time the converter took to adjust the output voltage to within the regulation tolerance set in the Output page of the Full Power Assist control symbol.
The value "never left regulation" is returned if the output under test never left the regulation window.
The value "left regulation and never recovered" is returned if the output under test leaves the regulation window and does not recover before the end of the simulation.

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.

Scalar 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.
Overshoot_V`{load_name}`	The maximum value of the output during the simulation time is less than the maximum overshoot specification value.
Undershoot_V`{load_name}`	The minimum value of the output during the simulation time is greater than the minimum undershoot specification value.

Testplan Example

The PulseLine() test objective is not used in the built-in testplans. To setup a PulseLine() test objective, you can start with a built-in testplan, and change the StepLine() tests to PulseLine() tests. A copy of the built-in testplan is automatically copied to the working schematics directory when you run the testplan for the first time.

Shown below is a single PulseLine() test created by modifying the DC/DC (1-input/1-output) testplan. This test configures the line to pulse from the Minimum to Maximum symbolic values. Both values are defined on the DC Input page of the Full Power Assist DVM control symbol. The timing of the pulse line event will be determined by the values on the Step/Pulse Line page of the Full Power Assist DVM control symbol. The load is set to 50% of the full load maximum value with a Load function.

*?@ Analysis	Objective	Source	Load	Label
Transient	PulseLine(INPUT:1, Minimum, Maximum, Minimum)		Load(OUTPUT:1, 50%)	Transient\|Pulse Line\|50% Load\|Vin Minimum to Vin Maximum

Optional Parameter String

The following PulseLine() test objective uses the OPTIONAL_PARAMETER_STRING argument to set the output load to pulse between the Minimum to Maximum symbolic values and sets the pulse time delay to 25us, the rise time to 100us, the pulse duration to 1ms, and the fall time to 100us.

PulseLine(INPUT:1, Minimum, Maximum, Minimum, TIME_DELAY=25u RISE_TIME=100u PULSE_WIDTH=1m FALL_TIME=100u)

Test Report

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