Two-step pulse triggering of dynistor power switches
Abstract
The performance of reversibly switching power dynistors is examined on the basis of physical processes which occur in their structure to determine their dv/dt and di/dt characteristics. Conditions for normal and most efficient operation are established by qualitative and quantiative analysis of available data. Pulse triggering of these thyristor-diode devices is considered, a particularly important parameter here being the lifetime of the high-conductance phase in internal p-N-n(+) diode segments from reverse injection till flow of positive anode current (reverse diode current). The length of this period is calculated according to the conventional simple theory of diffusion with charge storage, which is applied here to a semiinfinite model structure and the transient state with arbitrary waveforms of forward and reverse diode currents. The corresponding equation of ambipolar diffusion is solved for appropriate initial and boundary conditions for the hole concentration and its rate of change. A comparative evaluation of single-step and two-step triggering reveals the advantages of the latter mode with simultaneous uniform injection of initially induced charge.
- Publication:
-
USSR Rept Electron Elec Eng JPRS UEE
- Pub Date:
- April 1985
- Bibcode:
- 1985RpEEE.......51G
- Keywords:
-
- Diodes;
- Thyristors;
- Trigger Circuits;
- Ambipolar Diffusion;
- Electric Current;
- Hole Distribution (Electronics);
- Electronics and Electrical Engineering