This disclosure describes techniques for selecting one of a plurality of modes in which to operate an amplifier. The techniques include configuring input routing circuitry, coupled to first and second inputs of the amplifier, based on the selected one of the plurality of modes; selectively applying a resistance to an output of the amplifier, using feedback routing circuitry, based on the selected one of the plurality of modes; and selectively applying one of a plurality of reference voltages, using reference voltage routing circuitry, coupled to the first and the second inputs of the amplifier, based on the selected one of the plurality of modes.

An optical signal detection system includes a plurality of photodetectors configured to detect optical signals reflected from an environment surrounding the optical signal detection system and convert the optical signals into electrical signals. The optical signal detection system also includes an amplifier coupled to the plurality of photodetectors. The amplifier is shared by the plurality of photodetectors and configured to generate an output signal by amplifying an individual electrical signal converted by a corresponding photodetector. The optical signal detection system further includes a multiplexing circuit configured to selectively establish a connection between one of the plurality of photodetectors and the amplifier to amply the electrical signal converted by that photodetector.

A switchable amplifier and comparator circuit includes an operational amplifier having an inverting input, a non-inverting input, a first differential output and a second differential output, the first differential output switchably coupled to the inverting input and the second differential output switchably coupled to the non-inverting input. A first feedback capacitor is coupled to the inverting input and switchably coupled to the first differential output, a second feedback capacitor is coupled to the non-inverting input and switchably coupled to the second differential output. A capacitive load is switchably coupled between the first differential output and the second differential output. A diode clamp circuit is switchably coupled between the first differential output and the second differential output. A resistive load is switchably coupled between the first differential output and the second differential output.

First switches are respectively connected between multiple input terminals and an inverting input of an operational amplifier. Second switches and feedback resistors are respectively sequentially series-connected between an output of the operational amplifier and nodes between the multiple input terminals and the first switches. Third switches are respectively connected between nodes between the second switches and the feedback resistors and an output terminal of an amplification circuit with an analog multiplexer.

This disclosure describes techniques for selecting one of a plurality of modes in which to operate an amplifier. The techniques include configuring input routing circuitry, coupled to first and second inputs of the amplifier, based on the selected one of the plurality of modes; selectively applying a resistance to an output of the amplifier, using feedback routing circuitry, based on the selected one of the plurality of modes; and selectively applying one of a plurality of reference voltages, using reference voltage routing circuitry, coupled to the first and the second inputs of the amplifier, based on the selected one of the plurality of modes.

This application relates to switch arrangements, in particular switch arrangements suitable for switchable connecting nodes of audio driving circuitry (100) that may, in use, experience a signal swing depending on an output audio driving signal (V.sub.D). A switch arrangement (300) comprises first and second transistors (301 and 302) of the same polarity type connected in series between the first and second nodes, with a third transistor (303) connected between a defined voltage (V.sub.S) and an intermediate node (N3) between the first and second transistors. The first transistor (301) has a drain connection to the first node (N1) and a source connection to the intermediate node (N3). The second transistor (302) has a drain connection to the second node (N2) and a source connection to the intermediate node (N3). The third transistor (303) has a source connection to the defined voltage (V.sub.S) and a drain connection to the intermediate node (N3) and regulates the voltage at the intermediate node when the switch arrangement is in an off state.

An optical signal detection system includes a plurality of photodetectors configured to detect optical signals reflected from an environment surrounding the optical signal detection system and convert the optical signals into electrical signals. The optical signal detection system also includes an amplifier coupled to the plurality of photodetectors. The amplifier is shared by the plurality of photodetectors and configured to generate an output signal by amplifying an individual electrical signal converted by a corresponding photodetector. The optical signal detection system further includes a multiplexing circuit configured to selectively establish a connection between one of the plurality of photodetectors and the amplifier to amply the electrical signal converted by that photodetector.

An operational amplifier includes: a first amplifier stage, configured to generate first output voltages according to first input voltages; a second amplifier stage, configured to generate second output voltages according to the first output voltages; a second output stage circuit, configured to replicate an equivalent or a scaled-down version of the first output stage circuit; a first common-mode feedback circuit, configured to keep an output common-mode voltage of the second output stage circuit at a predetermined value; a logic loop circuit configured to, when the operational amplifier operates in a direct current calibration phase, adjust a difference between the first output voltages; a bias circuit, configured to generate a voltage close to a common-mode voltage of the first output voltages produced after the operational amplifier is turned on, the voltage serving as a reference voltage of a second common-mode feedback circuit.

A Miller compensation circuit includes: a differential amplifier having an inverse input end configured to receive an input signal; an output transistor having an output end connected to a positive input end of the differential amplifier, a first end connected to a first power supply, a second end connected to an output end of the differential amplifier, and a third end being a voltage output end and connected to the positive input end and a load; a Miller capacitor connected to the output end of the differential amplifier; a follower; and a current sampling circuit configured to sample a first current of the output transistor. The load is also connected to a second power supply.

An image sensor and an operating method of the image sensor are provided. An image sensor includes a pixel array including a plurality of pixels, a ramp signal generator configured to generate a first ramp signal, a buffer including an amplifier of a super source follower structure and outputting a second ramp signal obtained by buffering the first ramp signal, and an analog-to-digital conversion circuit configured to compare a pixel signal output from the pixel array with the second ramp signal and converting the pixel signal to a pixel value.