Ludwig Dipl.-Ing. Leipold

A FET-controlled thyristor in SIPMOS technology

The SIPMOS (Siemens Power MOS) technology was developed for power MOSFETs as well as a. c. power switches in which MOS technology is functionally combined with bipolar devices. This technology which has process steps like those of conventional integrated MOS circuits was used to realize a FET-controlled thyristor. The SIPMOS thyristor shows excellent qualities with regard to on-state current (di/dt=4000 A/us) voltage immunity (dV/dt > 1200 V/us), and firing sensitivity.

Experimental study of a high blocking voltage power MOSFET with integrated input amplifier

Using a slight modification of the SIPMOS® (Siemens Power MOS) technology an integrated test structure has been realized containing a vertical power MOS transistor and an input amplifier. The input amplifier, hich greatly reduces the input capacitance, consists of a vertical n-channel transistor and a lateral p-channel transistor. By this way short switching times are possible even with high-ohmic drivers.

600 V / 5 A FET-triggered lateral opto-triac

Besides being used in the production of MOS transistors, the SIPMOS® (short for Siemens Power MOS) technology permits the manufacture of components in which bipolar and MOS structures are functionally integrated, e.g. an FET-controlled optotriac. This component consists of two inverse-parallel connected lateral thyristors which are driven with the aid of vertical MOS transistors. A highly sensitive phototransistor supplies the gate voltage of the vertical MOS transistors. The lateral thyristors are implemented by means of interlocking, finger-like structures which enable good chip utilization. The triac features a 4 × 4 mm2chip and has a blocking voltage of more than 600 V in both directions. An LED current of 2 mA is sufficient to trigger the component. For a continuous current of 5 A this results in a current-transfer-ratio of 2,500 to 1.