Title: Multi-channel signal processing circuit formed in a semiconductor integrated circuit

Abstract: A semiconductor chip contains a multi-channel signal-processing circuit for processing signals in different frequency bands (e.g., an AM and an FM receiver). An inductor is coupled via an external terminal on a package for the semiconductor chip to a first signal-processing circuit. A circuit detects when a connection is made between the inductor and a power supply terminal contained in the semiconductor chip. When the inductor is connected to the power supply terminals, the first signal-processing circuit is activated, while the second signal-processing circuit is deactivated. When the inductor is disconnected from the power supply terminal, the second signal-processing circuit is activated, while the first signal-processing circuit is deactivated. The circuit for detecting a connection between the inductor and the power supply terminal is either a circuit for detecting a potential change or a circuit for detecting an oscillating signal. The inductor may be either an oscillator coil or an IF transformer winding.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Higashiyama, Naotoshi (Tokyo, JP)
Doi, Kazuyuki (Tokyo, JP)

Application Number: 06/057370
Filing Date: 1979-07-13
Publication_date: 1983-04-19
Assignee: NIPPON ELECTRIC CO (JP)

Primary Class(es): 455/143 455/343.500, 455/188.100
Other Classes: H03D5/00; H04B1/16
US Patent Ref:

3614468	October, 1971	Ehlbeck et al.	307/465	LOGIC CIRCUIT
4050022	September, 1977	McFadyen et al.	455/334	AM-FM receiver having improved mode conversion

Other Refs: Other References: An AM/FM Radio Subsystem I.C.-Blaser et al, Fairchild Camera & Instruments Corp., Mountain View Calif., May 1977, pp. 129-135, IEEE Trans. on Consumer Electronics.

Primary Examiner: Bookbinder, Marc E.
Assistant Examiner:
Attorney: Laff, Whitesel, Conte & Saret

Claims: