Abstract: A circuit for sensing radiation with high sensitivity is disclosed. The circuit comprises a first transistor configurable to reset a voltage-level at a circuit node to a voltage reference. The circuit also comprises measurement circuitry configured to measure the voltage-level at the circuit node, and at least one photodiode configured to vary the voltage-level at the circuit node in response to radiation incident upon the photodiode during an integration period. The circuit also comprises processing circuitry configured to control the first transistor to reset the voltage-level at the circuit node and to subsequently configure the measurement circuitry to measure the voltage-level at a start and at an end of the integration period.

Abstract: An optical device for characterizing flicker from an ambient light source is disclosed. The device comprises a radiation-sensitive device configured to vary a current in response to incident radiation, a second or higher-order modulator configured to output data corresponding to the current, and processing circuitry configured to provide a real-time characterization of flicker in the incident radiation based upon an analysis of changes in the data. Also disclosed is an associated method of characterizing flicker from an ambient light source.

Abstract: In one embodiment an optical sensing arrangement includes a first sensor configured to provide a first sensor signal, a second sensor configured to provide a second sensor signal, an integration unit including a first input which is connected to the first sensor, a second input which is connected to the second sensor, a first output which is configured to provide a first integration signal as a function of the first sensor signal, and a second output which is configured to provide a second integration signal as a function of the second sensor signal, a comparing unit including a first input which is connected to the first output of the integration unit, a second input which is connected to the second output of the integration unit and an output configured to provide a comparison signal as a function of the first and the second integration signal, and a control unit including a first input which is coupled to the output of the comparing unit, wherein the control unit is configured to evaluate pulses of the com

Abstract: An ambient light sensor is provided that includes a sensor input having a delta-sigma analogue to digital converter. The delta-sigma analogue to digital converter includes a switched capacitor, a common mode voltage source, a reference voltage source, and a switch network. In a first clock phase, the switch network connects the switched capacitor to charge it to either a sum or difference voltage. In a second clock phase, the switch network connects the switched capacitor to transfer charge into a summing junction. A controller controls the switch network in response to a comparator output to connect the switched capacitor to either the common mode voltage or the reference voltage while in the first clock phase.

Abstract: A switch circuit for use in a single-ended switched-capacitor circuit for front-end circuitry of a sensor device is disclosed. The switch circuit comprises a first transistor and a second transistor having a same channel-type as the first transistor. A first node is connected to a source of the first transistor and a drain of the second transistor and a second node is connected to a drain of the first transistor and a source of the second transistor. Also disclosed is a sampling circuit comprising the switch circuit and a sampling capacitor, wherein the switch circuit is configurable to electrically couple the sampling capacitor to an integrator circuit or to a voltage reference. An integrated circuit device and a light to frequency converter or light sensor comprising the switch circuit is also disclosed.

Abstract: A sensor circuit comprising a sensor input includes a delta-sigma analogue to digital converter. The delta-sigma analogue to digital converter includes a switched capacitor, a common mode voltage source, a reference voltage source, and a switch network. The switch network, in a first clock phase, connects the switched capacitor to charge it to either a sum or difference voltage, and in a second clock phase connects the switched capacitor to transfer charge into a summing junction. A controller controls the switch network responsive to a comparator output to selectively connect the switched capacitor to one of the common mode voltage and the reference voltage in the first clock phase. Implementations of the sensor circuit transfer charge every clock cycle and have low noise and high sensitivity.

Abstract: An apparatus includes a differential current-to-voltage conversion circuit that includes an input sampling stage circuit, a differential integration and DC signal cancellation stage circuit, and an amplification and accumulator stage circuit. An input common mode voltage of the differential current-to-voltage circuit is independent of an output common mode voltage of the differential current-to-voltage circuit.

Abstract: A switch circuit for use in a single-ended switched-capacitor circuit for front-end circuitry of a sensor device is disclosed. The switch circuit comprises a first transistor and a second transistor having a same channel-type as the first transistor. A first node is connected to a source of the first transistor and a drain of the second transistor and a second node is connected to a drain of the first transistor and a source of the second transistor. Also disclosed is a sampling circuit comprising the switch circuit and a sampling capacitor, wherein the switch circuit is configurable to electrically couple the sampling capacitor to an integrator circuit or to a voltage reference. An integrated circuit device and a light to frequency converter or light sensor comprising the switch circuit is also disclosed.

Abstract: A proximity sensor (1) with crosstalk compensation comprises a transmitting circuit (10) to transmit a signal to be reflected at a target (2) and a disturbing object (3), and a receiving circuit (20) to receive a reflected signal (RS) having a useful component (RSI) and a noise component (RS2). The receiving circuit (20) comprises an output node (A20) to provide an output signal (Vout2) in dependence from the distance of the proximity sensor (1) from the target (2). The receiving circuit (20) comprises a crosstalk compensation circuit (100) comprising a first charging circuit (110) to provide a first charge for for coarse crosstalk compensation and a second charging circuit (120) to provide a second charge for fine crosstalk compensation. A control circuit (30) sets an amount of the first and the second charge so that the output signal (Vout2) of the crosstalk compensation circuit (100) is dependent on the useful component (RSI) and independent on the noise component (RS2) of the reflected signal (RS).

Abstract: A proximity sensor (1) with crosstalk compensation comprises a transmitting circuit (10) to transmit a signal to be reflected at a target (2) and a disturbing object (3), and a receiving circuit (20) to receive a reflected signal (RS) having a useful component (RSI) and a noise component (RS2). The receiving circuit (20) comprises an output node (A20) to provide an output signal (Vout2) in dependence from the distance of the proximity sensor (1) from the target (2). The receiving circuit (20) comprises a crosstalk compensation circuit (100) comprising a first charging circuit (110) to provide a first charge for for coarse crosstalk compensation and a second charging circuit (120) to provide a second charge for fine crosstalk compensation. A control circuit (30) sets an amount of the first and the second charge so that the output signal (Vout2) of the crosstalk compensation circuit (100) is dependent on the useful component (RSI) and independent on the noise component (RS2) of the reflected signal (RS).