Semiconductor device for electrostatic discharge protection

[0056]The circuits described herein comprise wells of a conductivity type, wherein the conductivity type may be either N-type or P-type. In the following embodiments, a circuit may be implemented with conductivity types as depicted in the accompanying figure. Alternatively, the embodiments may be implemented such that each conductivity type is the opposite of that shown in the figures and described in the accompanying text. For instance, wherein a PNP bipolar transistor is described comprising a first region of P conductivity type, a second region of N conductivity type, and a third region of P conductivity type, the conductivities of the regions may be flipped such that an NPN bipolar transistor may be alternatively implemented comprising the first region of N conductivity type, the second region of P conductivity type, and the third region of N conductivity type.

[0057]In the following descriptions, common numerical designations may be used for similar, corresponding parts across mult