The SCR may include a PNP transistor (Q2) and an NPN transistor (Q3), the PNP transistor having a base in common with a collector of the NPN transistor and the PNP transistor having a collector in common with a base of the NPN transistor.

The SCR may include a PNP transistor (Q2) and an NPN transistor (Q3), the PNP transistor having a base in common with a collector of the NPN transistor and the PNP transistor having a collector in common with a base of the NPN transistor.

The SCR may include a PNP transistor (Q2) and an NPN transistor (Q3), the PNP transistor having a base in common with a collector of the NPN transistor and the PNP transistor having a collector in common with a base of the NPN transistor.

Semiconductors are used to not only build p-n junctions or diodes, but also transistors, which are n-p-n or p-n-p junctions.

Included in this classification are devices analogous to diodes, field effect transistors, p-n-p transistors, and n-p-n transistors, and pH sensors, among others.

The cathode of the SCR may be directly coupled to a base of the additional NPN transistor, and a collector and emitter of the additional NPN transistor may be directly coupled in series between VCC and ground.

There is a pnp or npn transistor (T5), the off-state current of which, which changes dependently upon the temperature, triggers a change in the base current (I) of the power transistor (T1, T2, T3).

Thus, this Fe doped InP layer (55a) will also effectively reduce the leakage current flowing through the p-n-p-n current blocking channel as mentioned above.

In an n-p-n device, an acceptor, e.g., Be, is implanted into an n-type collector region (11) supported by a substrate (10) to create a p-type base layer (15).