The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 25, 1993
Filed:
Jun. 29, 1989
Applicant:
Inventor:
Richard R Suter, Beaverton, OR (US);
Assignees:
Seiko Corp., both of, JP;
Seiko Epson Corp., both of, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ; G05F / ;
U.S. Cl.
CPC ...
4551822 ; 4551922 ; 455344 ; 323281 ; 323316 ;
Abstract
An AFC switch circuit is controlled by an select input logic signal for providing a selected output signal to control the local oscillator in a miniature FM receiver. The output signal has a voltage equal to either an AFC signal voltage for AFC operation of the receiver, or a reference voltage for synthesized operation of the receiver. The AFC switch circuitry employs bipolar transistors in current mirror configurations to minimize voltage offset and to enhance isolation between the unselected input and the output while operating on a power supply voltage less than 3 volts.