Circuit for providing a high and a low impedance and a system comprising the circuit
AssigneeSonion Nederland B.V.
InventorsAdrianus Maria Lafort, Michiel van Nieuwkerk
Life of this patent
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Abstract
A system including a transducer and an amplifier as well as a circuit which always has a high impedance at low voltages. In addition, at high voltages, the circuit has a high impedance at high frequencies but a low impedance at low frequencies. In biased transducers, this circuit may be used between the charge pump and the transducer. In general, the circuit may be provided in a signal path between the transducer and the amplifier. The circuit has as an advantage that at startup, low frequency signals at high intensities may overload the amplifier, whereas at operation, higher frequency signals are desired fed to the amplifier at the same intensity. This is facilitated by the circuit.
Claims15
A system comprising:
- a transducer with an output,
- an amplifier with an input,
- a transport element for receiving a signal from the transducer output and feeding a corresponding signal to the amplifier input and
- a circuit having a first and a second terminal and an impedance, between the first and second terminals which:
- exceeds 100 GOhm when an absolute voltage below 0.2V is provided over the first and second terminals,
- exceeds 100 GOhm when a signal with a frequency exceeding 50 Hz is provided over the first and second terminals and
- is lower than 10 GOhm when a signal with an absolute voltage exceeding 0.4V and a frequency lower than 10 Hz is provided over the first and second terminals,
- wherein the first terminal is connected to the transport element and the second terminal is connected to a predetermined voltage.
A system comprising:
- a first voltage supply configured to output a first voltage,
- a transducer comprising:
- one or more stationary elements,
- a movable element movable in relation to the stationary element(s),
- a voltage input configured to receive the first voltage and provide the first voltage between two of the movable element and the stationary element(s), and
- a transducer output,
- an amplifier with an input,
- a transport element for receiving a signal from the transducer output and feeding a corresponding signal to the amplifier input and
- a circuit having a first and a second terminal and an impedance, between the first and second terminals which:
- exceeds 100 GOhm when an absolute voltage below 0.2V is provided over the first and second terminals,
- exceeds 100 GOhm when a signal with a frequency exceeding 50 Hz is provided over the first and second terminals and
- is lower than 10 GOhm when a signal with an absolute voltage exceeding 0.4V and a frequency lower than 10 Hz is provided over the first and second terminals,
- wherein the first terminal is connected to the voltage input and the second terminal to a predetermined voltage.
Dependencies are inferred from the claim text.