(under subclass 174) Subject matter in which four layer devices are used (e.g., pnpn transistors).
SEE OR SEARCH CLASS
257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes),
107, 181 for regenerative type devices.
326, Electronic Digital Logic Circuitry, appropriate subclasses for electronic logic circuits utilizing four or more layer devices.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous circuits utilizing four or more layer devices.
