The forward voltage measuring device DM 659 is developed for the measurement of the forward voltage of power semiconductors and of the output and transfer characteristics of IGBTs. The DM 659 is designed as well for manual usage as for integration into automated test equipment.

In measuring the forward voltage of a semiconductor, the test device is operated with a load current pulse of up to 5,000 A. The pulse width is adjustable in a range from 100 to 500 µs.

The testing current is allocated by an internal capacitor bank. To recharge this unit after every measurement a recovery period of 250 ms max. is required, de-pending on the quantity of the testing current.

Configuring the measurement system via serial interface or external control the transmitted data will be displayed and used for the measurement.

The automatic mode enables the generation of characteristic curves. Therefore the system performs several measurements at in-creasing current values, starting at a selected base value.

The DM 659 has software to record up to 16 curves in one diagram and each curve can be denoted. Furthermore the curves can be stored or printed as single data arrays. They also can be exported into an Excel file for further application.