A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

An amplification apparatus includes an amplifier having an inverting terminal, and a non-inverting terminal connected to a reset voltage node, a first capacitor connected to the inverting terminal, an input voltage being applied to the first capacitor, a second capacitor connected to the inverting terminal and an output terminal of the amplifier, and a duty-cycled resistor, connected in parallel to the second capacitor, including a first resistor. The duty-cycled resistor is configured to connect the first resistor and the inverting terminal and to disconnect the first resistor and the reset voltage node during a first time interval included in a period to complete an on-and-off cycle of the duty-cycled resistor, and disconnect the first resistor and the inverting terminal and to connect the first resistor and the reset voltage node during a second time interval included in the period.

An amplifier circuit includes: an operational amplifier that includes two input terminals and an output terminal; a voltage-dividing resistor circuit electrically connected to the output terminal and that includes a voltage-dividing terminal that outputs a potential obtained by voltage-dividing a potential of the output terminal and a feedback resistor circuit electrically connected to the voltage-dividing terminal and one of the two input terminals. The voltage-dividing resistor circuit includes a plurality of resistors that each include terminals and a switch. The plurality of resistors includes a first resistor and a second resistor. The first resistor includes a terminal that corresponds to the voltage-dividing terminal. The switch switches, from a first terminal of the first resistor to a second terminal of the second resistor, the terminal that corresponds to the voltage-dividing terminal.

A circuit includes a first amplifier that first compares a ramp signal and a reset signal of a pixel signal output from a pixel array in a first operation period, second compares the ramp signal and an image signal of the pixel signal in a second operation period, and generates a first output signal in the first and second operation periods based on first and second comparison results; and a second amplifier that charges a capacitor in response to a second auto-zero signal in a second auto-zero period, stops an operation of the second amplifier from a time point at which the second auto-zero period ends to a time point at which the first operation period starts, and generates a second output signal based on the first output signal in the first operation period and the second operation period.

A method and apparatus of global coarse baseline correction (GCBC) for capacitive scanning. An input device may include a number (N) of sensor electrodes, a GCBC circuit, and detection circuitry. Each sensor electrode is associated with a respective channel. The GCBC circuit produces sensing signals in each of the N channels and the detection circuitry may detect changes in the capacitances of one or more sensor electrodes based on the sensing signals. In some implementations, the GCBC circuit may include a current source which outputs a first current, a transimpedance amplifier (TIA) which converts the first current to a sensing voltage, and a number (N) of resistors that can be coupled between the output of the TIA and the N sensor electrodes, respectively. The coupling of each resistor between the TIA and a respective sensor electrode produces a sensing signal in the channel associated with the sensor electrode.

A semiconductor device including an amplifier with improved accuracy is provided. The semiconductor device includes a switch, a capacitor, a chopping circuit, and the amplifier. The amplifier includes a non-inverting input terminal, an inverting input terminal, an inverting output terminal, and a non-inverting output terminal. The semiconductor device, with use of the switch and the capacitor, has a function of sampling and holding a first potential and a second potential input in a first period. The chopping circuit is provided on each of the input terminal side and the output terminal side of the amplifier, and the first potential and the second potential are each input to either one of the non-inverting input terminal and the inverting input terminal in a second period. In a third period, the first potential and the second potential are each input to either one of the non-inverting input terminal and the inverted input terminal, which is different from the second period. In a similar manner, the inverting output terminal and non-inverting output terminal are replaced by the chopping circuit in the second period and the third period to be output from the semiconductor device.

A method and apparatus of global coarse baseline correction (GCBC) for capacitive scanning. An input device may include a number (N) of sensor electrodes, a GCBC circuit, and detection circuitry. Each sensor electrode is associated with a respective channel. The GCBC circuit produces sensing signals in each of the N channels and the detection circuitry may detect changes in the capacitances of one or more sensor electrodes based on the sensing signals. In some implementations, the GCBC circuit may include a current source which outputs a first current, a transimpedance amplifier (TIA) which converts the first current to a sensing voltage, and a number (N) of resistors that can be coupled between the output of the TIA and the N sensor electrodes, respectively. The coupling of each resistor between the TIA and a respective sensor electrode produces a sensing signal in the channel associated with the sensor electrode.

The present application provides a capacitance detection circuit, which could reduce the influence of screen noise on capacitance detection. The capacitance detection circuit includes: an amplification circuit connected to the capacitor to be detected, and configured to convert a capacitance signal of the capacitor to be detected into a voltage signal, the voltage signal being associated with the capacitance of the capacitor to be detected; and a control circuit connected to the amplification circuit, and configured to control an amplification factor of the amplification circuit to be a first amplification factor in a first period, and to control the amplification factor of the amplification circuit to be a second amplification factor in a second period, where noise generated by the screen in the first period is less than noise generated by the screen in the second period, and the first amplification factor is greater than the second amplification factor.

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.