Hitachi IGBT Module Application Manual
Example of Verification
Verification Circuit Configuration
that the top arm turns ON when the collector current of the bottom arm is shut down and a signal is given to
the top and the bottom driver circuit.
Figure 47. Verification Circuit Configuration
How to Observe Switching Waveforms
The non-overlap at the top and the bottom arm can be checked in various ways. Special care must be
taken when observing voltage waveforms with different potential levels. Any floating-state voltage can be
observed with an optical insulation cable or with a differential probe, but these methods require elaborate care
concerning delays and other factors. In particular, to observe the gate voltage of the bottom arm with a
voltage probe and the gate current of the top arm, a non-contact current transformer (CT) is recommended,
such as one manufactured by Pierson (US).