The switching loss in a power supply determines its efficiency. You can easily characterize instantaneous power loss and conduction power loss at the switching device over a designated switching cycle. The dynamic ON resistance measurement shows you power loss while the power transistor is conducting.

To determine the reliability of the power supply it is very important to measure the power loss during dynamic load changes and to observe the SOA (safe operating area) plot. Using deep acquisition memory on the scope with the SOA plot, you can easily identify improper power transistor behavior.

Power supply designers need to characterize the line power for power quality, harmonics and conducted emissions under different operating conditions of the power supply. Some of the implicit measurements are real power, apparent power, reactive power, power and crest factor and graphical display of harmonics with respect to standards such as IEC 61000-3-2 (Class A,B,C,D) and RTCA DO 160E. By using a current probe and the power measurement software (equipped with an FFT math function), you can measure conducted power line harmonics.

Modulation analysis allows you to quickly see the on-time and off-time information of the PWM signal, which is difficult to visualize because the information bandwidth is much lower than the pulse switching frequency. Plotting the embedded variation of on time or off time in the PWM signal over a long period of time can reveal the control loop response of the feedback loop system. This measurement performs data trending on the switching variation of the acquired waveform in the following formats:

• Frequency versus time
• Period versus time
• Duty cycle versus time
• Positive pulse width versus time

This module includes characterizing the ripple (either AC or switching) component in the output DC voltage. Ripple is the residual AC component that is superimposed on the DC output of a power supply. Line frequency and switching frequency can contribute to the ripple. This measurement presents the peak-to-peak ripple value as well as the frequency response of the captured signal.

This module measures the time taken to get to the steady output voltage of the power supply after the input voltage is applied (turn on time) and for the output voltage of the power supply to turn off after the input voltage is removed (turn off time).

Power supplies are subject to transient conditions, such as turn-on and turn-off transients, as well as sudden changes in output load and line input voltage. These conditions lead to one of the key specifications of the power supplies: load transient response. This module measures the load transient response of the DC output; namely, the time taken for the DC output to stabilize during a load change.

After a single test or a test module has been run, the View Report tab populates with measurement data and graphs for your archival and date sharing purposes. Reports are saved in a .htm format. Each report contains an up-front summary of pertinent test information.

Reports are automatically saved to a test folder on the directory of your choice.