MOSFET analog signal squaring circuit
AssigneeRCA Corporation
InventorPaul D. Filliman
Life of this patent
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Abstract
A MOSFET analog signal squaring circuit is disclosed. A first MOSFET has a source electrode coupled to a bias voltage source, a gate electrode coupled to an input terminal, and a drain electrode coupled to an output terminal. A signal inverter is also coupled to the input terminal. A second MOSFET has a source electrode coupled to the bias voltage source, gate electrode coupled to the signal inverter, and a drain electrode coupled to the output terminal. A load impedance is coupled between the output terminal and a supply voltage source.
Claims8
A MOSFET analog signal squaring circuit, including input and output terminals, and bias and supply voltage terminals, said squaring circuit comprising:
- a first MOSFET having a source electrode coupled to said bias voltage terminal, a gate electrode coupled to said input terminal, and a drain electrode coupled to said output terminal;
- a signal inverter coupled to said input terminal;
- a second MOSFET having a source electrode coupled to said bias voltage terminal, a gate electrode coupled to said signal inverter, and a drain electrode coupled to said output terminal;
- and
- a load impedance coupled between said output terminal and said supply voltage terminal.
A television receiver comprising:
- a source of a compressed audio sound signal;
- a first fixed deemphasis filter having an input terminal coupled to said source and an output terminal;
- a variable deemphasis network having a signal input coupled to said output terminal of said first fixed deemphasis filter, a control input terminal and an output terminal;
- a variable gain amplifier having a signal input terminal coupled to said output terminal of said variable deemphasis network, a control input terminal and an output terminal;
- a second fixed deemphasis filter having an input terminal coupled to said output terminal of said variable gain amplifier and an output terminal;
- a first bandpass filter having an input terminal coupled to said source and an output terminal;
- a first root mean square detector having an input terminal coupled to said output terminal of said first bandpass filter and an output terminal coupled to said control input terminal of said variable deemphasis network;
- a second bandpass filter having an input terminal coupled to said source and an output terminal;
- a second rms detector having an input terminal coupled to said output terminal of said second bandpass filter and an output terminal coupled to said control input terminal of said variable gain amplifier;
- wherein:
- at least one of said first and second rms detectors includes a MOSFET analog signal squaring circuit including input and output terminals and bias and supply voltage terminals, said squaring circuit comprising:
- a first MOSFET having a source electrode coupled to said bias voltage terminal, a gate electrode coupled to said input terminal and a drain electrode coupled to said output terminal;
- a signal inverter coupled to said input terminal;
- a second MOSFET having a source electrode coupled to said bias voltage terminal;
- a gate electrode coupled to said signal inverter and a drain electrode coupled to said output terminal;
- and a load impedance coupled between said output terminal and said supply voltage terminal.
Dependencies are inferred from the claim text.