KDEE-LE ComCell Contact: Dr.-Ing. Christian Nöding

Since 2011, the software "ComCell" for automated double pulse experiments has been continuously developed. In the meantime, we have a universal software that can control a variety of different hardware and aggregate data. The MatLAB-based software (available as 64-bit standalone version including industrial license) controls and regulates different hardware components to aggregate a high number of degrees of freedom in a convenient interface.

Our software works with a wide range of different devices in various combinations:

  • Oscilloscopes:
    • Tektronix (DPO7000 series, MSO5 series, and MSO6 series).
    • LeCroy (HDO6000 series and others)
    • Yokogawa
    • Keysight InfiniiVision
    • Siglent and others
  • Several oscilloscopes (also of different types and manufacturers) can be used simultaneously to expand the number of channels. Thus parallel measuring processes of different components are possible
  • Voltage source:
    • EA PSI9x series
    • Regatron TopCon series
    • FuG MCP series
    • Delta-Electronica SM3300
    • Heiden HPS
    • TTi QPX600DP
    • TDK GEN1000
  • Temperature devices:
    • OMRON E5CC controller
    • Voetsch/Weiss climate chamber
    • Thermostream
    • Huber 815w
    • Julabo FP51SL
  • Other devices:
    • Beckhoff industrial relays (e.g. for automatic switching of the high and low side of a half bridge)
    • Integration of temperature sensors (J- and K-types or also digital sensors, e.g. DS18B20)
    • Laboratory power supplies from GwInstek and Rohde+Schwarz
  • Pulse generators:
    • KDEE_MfPG pulse generator
    • TTi TGP3152
    • Keysight 33500
    • Special solutions based on a C2000 F28335 with temporal resolution of up to 150 picoseconds

The integration of new hardware can also be realized at short notice - depending on the scope.

Data acquisition software

The "ComCell" software is responsible for controlling the individual devices and the actual measurement process. The software manages the individual configurations (e.g. in case of different driver configurations, or other hardware changes) and allows an easy assignment of the measurement results to the respective configurations used.

During the measurements, the channel settings of the oscilloscope are automatically adapted to the respective conditions. In this way, significant recovery currents can also be recorded during turn-on measurements, or variable switch-off overvoltages during turn-off measurements. An adjustable headroom above and below the measurement signals is maintained in each case. This ensures optimum vertical resolutions of all channels at all times and thus optimum utilization of the AD converter of the measuring equipment.

Main screen of the ComCell software

The planned measurement sequence is prepared via numerous dialogs and input windows. For example, the software automatically corrects a DC link capacitor that is too small and compensates for the voltage drop across the DC link caused by a current that is too large. The software also determines the optimum vertical gain of the individual oscilloscope channels via a pre-measurement, so that the optimum resolution of the ADC can always be used even with high oscillations.

All data are stored as raw CSV files in a directory structure incl. original screenshot of the scope, so that you have access to the measurement data even without the ComCell software. Meta files including measurement conditions are always stored in the respective directories.

Settings for switching loss measurements

Analysis software

Once the signals have been acquired, the analysis software can automatically determine a large number of individual parameters and export them via an export function to a clearly structured Excel spreadsheet or to departments own open source tool"TopBench" for further processing. Thus, a fully automated acquisition and processing of the semiconductor properties and a directly subsequent calculation of the power electronics is possible.

The analysis software automatically detects all necessary parameters (90%/10% limits, du/dt, di/dt, delay times, leakage inductances, skewing of the measuring equipment) and supports, in addition to IEC60747, a large number of different integration parameters for determining the switching energies.

Main screen of the SwitchingLossAnalyzer
Superimposed individual measurements for comparison
Overview display of all measured points

If desired, the Analyzer software exports all relevant information clearly into an interactive Excel file. Here, individual graphs are automatically created for each configuration during export, so that you can check the results directly. In addition, all determined properties (du/dt, delay, energy, overvoltage, etc) are included in table form:

Automatically generated Excel representation of the loss curves
Export of all relevant data for individual data sheet for further processing

Pulse generation

Besides commercially available solutions (e.g. arbitrary signal generator with adjustable voltage) we offer our own pulse generator.

The pulse generator we developed uses a dsPIC to generate different waveforms and is powered directly via USB. TTL level signals with a time resolution of 100ns are output via two BNC connectors to control a gate driver circuit. Numerous different waveforms can be output (including single and double pulse, various PWM signals, signals for short circuit checking and soft switching, etc.).

KDEE MiniPG Pulse Generator
Possible output pulse shapes with a time resolution of 100ns