Purpose

This example demonstrates how you can use the Sweep Loop step to characterize a transistor.

Example File Location

<TestStand Public>\Examples\Interfacing with Hardware\TransistorCharacterizationUsingSweepLoop\TransistorCharacterization.seq

Highlighted Features

• Sweep Loop Step Type

Major API

None

Prerequisites

None

How to Use This Example

Complete the following steps to use this example.

1. On the Steps pane of the MainSequence sequence, review the steps in the Setup step group.
   • The Get Sequence File Directory step gets the directory of the example sequence file.
   • The Identify CSV Output file step creates the output stream in the sequence file directory.
   • The Write Headers to CSV Output file step adds the row that contains "Temperature (C)", "Voltage (CE)", "Current (Ic)", and "Current gain" denoting the headers for the subsequent records.
2. On the Steps pane, review the steps in the Main step group.
   • The Sweep Transistor - Temperature step sweeps on the junction temperature of the transistor.
   • The While loop containing the Measure Junction temperature step executes until the measured temperature is equal to the desired junction temperature ±0.1 as set in the Sweep loop step above.
   • The Sweep Transistor - Voltage and Current step sweeps on various Voltage and Current parameters.
   • The Calculate Vce step calculates the Collector-Emitter voltage as the difference of voltage between Vcc and Ve.
   • The Measure Ic step simulates the measuring of Collector current.
   • The Measure Ie step simulates the measuring of Emitter current.
   • The Calculate DC Current Gain (hFE) step calculates the gain in current as the ratio of output current (Ic) to input current (Ie).
   • The Write Record to CSV Output file step writes the values of Temperature, Vce, measured Ic and Current gain to the output CSV file for each iteration of the Sweep Loop step.
3. On the Steps pane, review the steps in the Cleanup step group.
   • The Close CSV Output file Stream reference step closes the reference to the CSV Output File Stream.
4. Select Execute»Single Pass to execute the sequence.
5. The Temperature, Vce, Ic and Current gain values are logged to <TestStand Public>\Examples\Interfacing with Hardware\TransistorCharacterizationUsingSweepLoop\output.csv.