CMOS high impedance circuit
AssigneeSonionmicrotronic Nederland B.V.
InventorAdrianus M. Lafort
Life of this patent
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Abstract
A high impedance circuit includes a diode-connected MOSFET circuit. This circuit may be used in a buffer amplifier of a hearing aid microphone, coupled across an input of the buffer amplifier and providing a high input impedance.
Claims42
A high input impedance input circuit for a buffer amplifier/preamplifier of a hearing aid microphone said high input impedance circuit comprising:
- a CMOS transistor circuit providing an impedance equivalent to a pair of antiparallel diodes connected between an input of said buffer amplifier and a reference voltage.
A method of constructing high input impedance input circuit for a buffer amplifier/preamplifier of a hearing aid microphone on a single integrated circuit chip with said buffer amplifier/preamplifier said method comprising:
- forming on said integrated circuit chip at least one p-channel transistor or at least one n-channel transistor coupled across an input of said buffer amplifier/preamplifier and providing a high impedance.
A high input impedance input circuit for a buffer amplifier/preamplifier of a hearing aid microphone, said high input impedance circuit comprising a diode-connected MOSFET circuit.
A high input impedance circuit comprising a diode connected MOSFET circuit.
A method of constructing a high impedance circuit, said method comprising:
- forming on an integrated chip at least one p-channel transistor and at least one n-channel transistor coupled in circuit to provide high impedance.
A microphone, comprising:
- a transducing assembly for converting an input sound into an electrical signal;
- a buffer amplifier for amplifying said electrical signal;
- and
- a high input impedance input circuit for said buffer amplifier, said high input impedance circuit comprising a diode-connected MOSFET circuit.
Dependencies are inferred from the claim text.