Using Memory Effectively - LAB WM206 (PMA2 related)

How to Set Up Acquisition and Math Memory Effectively. The LeCroy X-StreamTM oscilloscopes offer the longest available acquisition memories. These long memories, combined with high sampling rate, minimize the possibility of aliasing and assure accurate measurement of fast waveforms.

Modulation Analysis - PWM - LAB WM421 (PMA2 related)

Use Track And Timing Functions To Analyze PWM Signals. Pulse Width Modulation (PWM) is commonly used in power supplies and industrial control systems. It has the advantage of efficiently driving switched mode devices at a fixed frequency. LeCroy’s Jitter and Timing Analysis 2 (JTA2) analysis option contains a number of functions and parameters to extract the underlying modulation signal, making it possible to assess correct tracking and linearity in PWM regulators/controllers.

Power - Real And Apparent - LAB WM428 (PMA2 related)

A Tutorial On Basic Line Power Measurements. Oscilloscopes measure current and voltage and, through the magic of mathematics, calculate power. Unfortunately, power comes in a large number of guises: instantaneous, real, apparent, and reactive. This plethora of power terms often leads to confusion. The Power Measure Analysis (PMA2) software package simplifies these measurements and eliminates the necessity of setting up the proper math operations.

Safe Operating Area - LAB WM440 (PMA2 related)

Improving Reliability By monitoring Device Stress Limits. Every switching device has a maximum voltage, maximum current and maximum power specified by the device manufacturer, displayed on its technical application note. Reliability of the power supply is dependent on not exceeding these limits.

Power Device Analysis - LAB 438 (PMA2 related)

Measuring Power Loss in Switched Mode Power Supplies. Design goals for switched mode power supplies include designing more efficient power supplies that effectively reduce the size and costs of those supplies. Having tools that provide more insight into these circuits supports these goals, as well as providing a designer with more confidence
in power supply reliability under all operating conditions. One of the ways to improve the efficiency of your designs is to reduce the power losses within the circuit.

Control Loop Analysis - LAB 439 (PMA2 related)

Measuring Feedback Loop Response In Power Systems. Every power supply has a feedback loop that monitors the output voltage or current and keeps the device’s on-time appropriate to the load. This means that the power device conducts longer if the output voltage is too low. Most switched mode power supplies use pulse width (PWM) or frequency modulation (FM) in their control loops. Analysis of the loop dynamics requires the ability to demodulate these signals. Power Measure Analysis (PMA2) software, available in LeCroy X-Stream oscilloscopes, includes easy-to- use modulation analysis capabilities.

Measure Device Capacitance - LAB 418

Easy Circuit Measures Voltage Dependent Capacitance. There are many techniques for measuring capacitance. Some of these techniques require a function generator to provide either a sinusoidal, or step-function voltage source. The following design idea has the advantage of requiring no special excitation source, but rather relies on a simple test circuit, and the single-shot capture, and measurement capabilities inherent in digital oscilloscopes (DSO’s).

Modulation Analysis - PWM - LAB 421

Use Jitter And Timing Functions To Analyze PWM Signals. Pulse Width Modulation (PWM) is commonly used in power supplies and industrial control systems. It has the advantage of efficiently driving switched mode devices at a fixed frequency. LeCroy’s Jitter and Timing Analysis (JTA) math option contains a number of functions and parameters to extract the underlying modulation signal making it possible to assess correct tracking and linearity in PWM regulators/controllers.

Regulation And Ripple - LAB 422

Trend Functions Analyze Load Related Power Supply Specs. Power supply specifications include a large number of load dependent parameters including output regulation and ripple. LeCroy oscilloscopes offer an advanced math function called trending which allows the easy measurement of these types of specifications.

Rescaling Measurement Units - LAB 427

Use The Rescale Function For Non-Voltage Measurements. Oscilloscopes principally measure voltage and time. Measuring other electrical quantities, as a function of time, requires the use a transducer which converts the measured quantity into voltage. The Rescale math function in LeCroy Digital Oscilloscopes enables the users to convert this measurement into the proper units.

Power - Real and Apparent - LAB 428

Oscilloscopes measure current and voltage and through the magic of mathematics calculate power. Unfortunately, power comes in a large number of guises: instantaneous, real, apparent, and reactive. This plethora of power terms often leads to confusion. This application brief is intended to help clarify the confusion about the measurement of power.

Calculating Area In X-Y Displays - LAB 707A

Waveform Math Finds Area Enclosed By X-Y Display. Many applications involving cyclic phenomena result in the need to determine the area enclosed by an X-Y plot. A typical example is the power loss per cycle in a magnetic core which is proportional to the area enclosed by a plot of magnetic field intensity against flux density. This area can be readily measured using waveform math available in LeCroy oscilloscopes.

Setting Up FFT Span And Resolution - LAB 714

LeCroy's 93XX-WP02 FFT Processing option adds the power of frequency domain analysis to the 9300 series oscilloscopes. The FFT converts a time domain waveform into frequency domain spectrum similar to the display of an RF spectrum analyzer. Although the output displays are similar the operation of the FFT and an RF spectrum analyzer are very different.

Using Parameter Trend Plots - LAB 725

Power Supply Regulation Measurements Using Trend Plots. Trend plots, which are available in LeCroy oscilloscopes, graphically display up to 20,000 individual parameter measurements on each trace. Any, of over 100 available parameters, can be used as a source of the trend plot. When two trends are cross-plotted on an X-Y display the functional relationships between the two parameters can easily be examined.

Data Logging Using Trend Plots - LAB 731

Trend + Sequence Mode + Trigger Hold Off = Data Logger. Data Logging is the ability to make multiple measurements of key circuit parameters acquired simultaneously at known times. LeCroy oscilloscopes, equipped with the optional parameter analysis math package have all the tools necessary for data logging up to 4 parameters.

Frequency Response Measurements - LAB 740

Derive Frequency Response From Step Response. Filters, amplifiers, and control systems are usually characterized by their frequency response functions. These functions are usually shown in graphical form as plots of log amplitude vs. log frequency called Bode plots. Oscilloscopes are primarily time domain measuring instruments.

Measure Power In 3-Phase Systems - LAB 741

Use A DSO To Measure Power In 3 Wire, 3-Phase Systems . The power dissipated in a 3wire, 3-phase load can be determined using a LeCroy 4 channel oscilloscope by measuring two phase currents and two line voltages. For example, looking at the schematic in figure 1, the total power dissipated in a 3 -phase motor can be determined by measuring V_AC, V_BC, I_A and I_B.

Measuring Energy - LAB 742

Verifying Energy Measurements Using Capacitor Discharge. Some electro-static discharge (ESD) measurements require the measurement of discharge energy. In many of these experiments the oscilloscope can measure the discharge current or voltage but often both may not be available simultaneously.

Multi-Stage, Multi-Rate Filters - LAB 746

LeCroy's Digital Filter Package (DFP) option allows users to select any of 7 standard types as well as define a custom filter and apply the filter to measured data. A range of pass band limits and rolloff widths can be specified for the filters which are implemented as digital finite impulse response (FIR) filters. The range of band edge frequencies is a function of the scopes effective sampling rate. Using the four available math traces it is possible to implement multistage, multirate filters to extend the range of the DFP package filter limits.

Digital Filter Applications - LAB 747

Filters are circuits or devices in which the output gain and phase vary as a function of the frequency of the input. This frequency sensitivity makes them useful in removing undesirable elements of a signal or compensating for some frequency dependent distortion within the signal. LeCroy's Digital Filter Package (DFP) option offers a selection of several standard or a user defined, custom digital filter configuration. These can be applied in the analysis and measurement of waveforms as illustrated in the examples which follow. 

Measuring Phase Margin - LAB 748

Phase margin is a critical figure of merit which serves to indicate the stability of a closed loop control system. It is one of the most common design verification measurements made in power systems.

Customize Your Scope - LAB 812

CustomDSO files allow users to create custom menus with a series of user specific measurement operations behind them. Figure 1 includes a typical use of the CustomDSO file. Each user created menu in this example sets up a series of specific tests including both mask and parameter testing on multiple waveforms. An experienced scope users can easily produce a semi-automated test sequence which permits users with limited scope familiarity to operate the most advanced features of the scope.

Pulse Width Modulated Waveforms - LAB 910

Dynamically Stepping Duty Cycle From 1% To 99%. The LeCroy LW420 Arbitrary Waveform generator is an ideal source of pulse width modulated (PWM) signals commonly used in power, industrial control, and automotive electronics systems. The 1 Megabyte memory supports long test waveforms where the duty cycle of a pulsed waveform can be varied over a wide range without loss of signal continuity.

Using Current Probes - LAB 1013

LeCroy offers a series of AC/DC sensitive current probes with maximum continuous current ranges to 150 A and bandwidths to 50 MHz. Figure 1 shows the CP015 and CP150 current probes, the latest additions to the LeCroy current probe line. These probes join a family of current probes summarized in the table below.