United States Patent 3,539,884
November 10, 1970

Integrated Transistor and Variable Capacitor
Gerald Schaffner

Filed September 18, 1968
Image of US PATENT 3,539,884

Abstract of the Disclosure

A monolithic chip has an NPN transistor and a variable capacitance diode junction extending therein from the same surface. A common electrode which connects the cathode and the collector respectovely of the variable capacitance diode and the transistor is a concuctive case terminal of a package. The base and emitter electrodes of the transistor and the anode of the diode are connected to different insulated posts. A ceramic chip bypass capacitor is mounted on the conductive case electrode but no connected electrically to it and connected respectively to the base and the anode insulated posts. A common collector supply and reversed bias supply for the variable capacitance diode is provided to the common case electrode. The circuit is usable for AFC and any other tunable circuit wherein the control bias is used to control the tuning.
Figure descriptions: cover graphic

  • Figure 1 is a diagrammatic cross-sectional view of a monolithic chip made in accordance with the present invention.
  • Figure 2 is a schematic diagram showing the circuit equivalent of the Figure 1 illustrated structure.
  • Figure 3 is a diagrammatic isometric view of an assemblage in accordance with the teachings of the present invention and showing a monolithic chip of Figure 1 and a ceramic chip capacitor on a common case electrode.
  • Figure 4 is a schematic diagram of the assemblage of Figure 3 as used in a circuit for controlling the frequency of a frequency determining portion (of another device not shown).

 Citations [54]:
3,878,804 04/1965 Ullery et al. 3,341,755 09/1967 Husher et al. 3,453,505 07/1969 Offner et al.
National Museum of American History
HomeSearchChip TalkChip FunPatentsPeoplePicturesCreditsCopyrightComments