Abstract: The invention relates to NPN and PNP bipolar transistors and to a method for the production thereof, said transistors being characterised by a particularly high collector-emitter and collector-base blocking voltage. The blocking voltage is increased by a particular doping profile. An NPN bipolar transistor comprises a p-doped substrate (1), a trenched n-doped layer (3) forming the collector, a p-doped layer (7) which is arranged above the trenched n-doped layer and is made of a base and an n-doped layer which is arranged within the p-doped layer and forms an emitter of the transistor. A spatial charge area (RLZ 1) is formed between the p-doped layer and the trenched n-doped layer and a second spatial charge area (RLZ 2) is formed between the trenched n-doped layer and the p-doped substrate, which expands in the vertical direction on the collector when the transistor is operated with an increasing potential.

Abstract: The circuit for feeding a Wheatstone Bridge (DMS 1 . . . DMS 4) with a rectangular waveform alternating voltage which is derived from a single DC reference voltage, consists of a first operational amplifier (V 1) whose positive input is connected to the DC reference voltage and whose negative input is connected via the switches (S 5 and S 6) alternately to the one (A) or to the other (B) feed point of the bridge, and a second operational amplifier (V 2) whose positive input is connected to ground potential and whose negative input is connected to one measuring input (C) of the bridge. The outputs of the two operational amplifiers (V 1 and V 2) are connected via the switches (S 1 . . . S 4) alternately to the one (A) and to the other (B) feed point of the bridge, and the output signal is taken off at the second measuring output (D) of the bridge.