Abstract: A sense amplifier circuit comprising a first-, second-, third- and fourth-amplification-blocks, each amplification-block comprising: an amplification-block-transistor comprising and an amplification-block-resistor. The amplification-block-transistor includes: a first-conduction-channel-terminal, a second-conduction-channel-terminal that is connected to an amplification-block-output-node, and a control-terminal that is connected to an amplification-block-control-node. The sense amplifier circuit also comprises: an amplification-block-resistor connected in series between an amplification-block-input-node and the first-conduction-channel-terminal; a first-bias-voltage-source connected to the amplification-block-control-nodes of the first- and third-amplification-blocks, a second-bias-voltage-source connected to the amplification-block-control-nodes of the second- and fourth-amplification-blocks.

Abstract: A sense amplifier circuit comprising a first-, second-, third- and fourth-amplification-blocks, each amplification-block comprising: an amplification-block-transistor comprising and an amplification-block-resistor. The amplification-block-transistor includes: a first-conduction-channel-terminal, a second-conduction-channel-terminal that is connected to an amplification-block-output-node, and a control-terminal that is connected to an amplification-block-control-node. The sense amplifier circuit also comprises: an amplification-block-resistor connected in series between an amplification-block-input-node and the first-conduction-channel-terminal; a first-bias-voltage-source connected to the amplification-block-control-nodes of the first- and third-amplification-blocks, a second-bias-voltage-source connected to the amplification-block-control-nodes of the second- and fourth-amplification-blocks.

Abstract: An audio processing system is described including an amplifier configured to receive a first audio signal and output the first audio signal to an acoustic transducer comprising a voice coil. A sensor detects a signal corresponding to voice coil current of the acoustic transducer. A controller compares the first audio signal and the detected signal and determines a second audio signal from the comparison. The second audio signal is representative of an external sound source detected via the acoustic transducer. The audio processing system may simultaneously output the first audio signal and receive the second audio signal using the same acoustic transducer.

Abstract: An audio processing system is described including an amplifier configured to receive a first audio signal and output the first audio signal to an acoustic transducer comprising a voice coil. A sensor detects a signal corresponding to voice coil current of the acoustic transducer. A controller compares the first audio signal and the detected signal and determines a second audio signal from the comparison. The second audio signal is representative of an external sound source detected via the acoustic transducer. The audio processing system may simultaneously output the first audio signal and receive the second audio signal using the same acoustic transducer.

Abstract: The invention relates to a mixer circuit, a receiver comprising a mixer circuit, and a method of mixing an input signal with an oscillator signal. A mixer circuit 300 according to the invention comprises a first input node 301 and a second input node 302 for receiving an input signal Vin, a first output node 321 and a second output node 322, voltage to-current conversion means R1a, R1b, R2a, R2b, and switching means M1, M2, M3, M4 operatively coupled to each other and to the first input node 301, the second input 305 node 302, the first output node 321, and the second output node 322 to generate a mixed input signal the first output node 321 and the second output node 322 in response to an oscillator signal.