An active clamp photoelectric sensing device includes an input terminal, a first output terminal, a current-to-voltage conversion circuit, and an active clamp circuit. The input terminal receives an input current. The first output terminal outputs a first output voltage. The current-to-voltage conversion circuit is coupled between the input terminal and the first output terminal, and is used to discharge and lower potentials of the input terminal and the first output terminal to a first set voltage according to the state of a reset signal, or is used to gradually increase the first output voltage to a second set voltage. The active clamping circuit is coupled to the current-to-voltage conversion circuit, and is used to clamp the upper limit of the first output voltage to the second set voltage.

Assemblies of electronic components for reception of data using optical fibre and methods for providing same. Assemblies comprise a photodiode; an amplifier coupled to the photodiode; at least one feedback resistor coupled between the input and output of the amplifier; an arrangement of at least two MOS transistors of same channel polarity and configured in parallel with the feedback resistor(s); a system for sensing received input signal level and applying a bias voltage to gates of the MOS transistors, the bias voltage varied according to the received input signal level to control a resistance apparent through the arrangement of MOS transistors; at least one capacitor configured to couple signals from the amplifier output to a gate of at least one of the MOS transistors; and at least one bias resistor configured to couple the bias voltage to a gate of at least one of the MOS transistors.

An optical network system comprising an optical line terminal (OLT) and an optical network unit (ONU) coupled to the OLT and configured to communicate with the OLT via an optical signal. At least one of the OLT or the ONU comprises a closed-loop gain controlled transimpedance amplifier (TIA) comprising a first amplifier configured to receive an input signal, generate a main output signal by amplifying the input signal according to a gain factor of the first amplifier, and generate an auxiliary output proportional to the input signal, an average detector coupled to the first amplifier and configured to receive the auxiliary output, and determine an average of the input signal according to the auxiliary output, and a feedback loop coupled to the first amplifier and the average detector and configured to control the gain factor of the first amplifier according to the average of the input signal.

An optical network system comprising an optical line terminal (OLT) and an optical network unit (ONU) coupled to the OLT and configured to communicate with the OLT via an optical signal. At least one of the OLT or the ONU comprises a closed-loop gain controlled transimpedance amplifier (TIA) comprising a first amplifier configured to receive an input signal, generate a main output signal by amplifying the input signal according to a gain factor of the first amplifier, and generate an auxiliary output proportional to the input signal, an average detector coupled to the first amplifier and configured to receive the auxiliary output, and determine an average of the input signal according to the auxiliary output, and a feedback loop coupled to the first amplifier and the average detector and configured to control the gain factor of the first amplifier according to the average of the input signal.

Methods and systems for a distributed optoelectronic receiver are disclosed and may include an optoelectronic receiver having a grating coupler, a splitter, a plurality of photodiodes, and a plurality of transimpedance amplifiers (TIAs). The receiver receives a modulated optical signal utilizing the grating coupler, splits the received signal into a plurality of optical signals, generates a plurality of electrical signals from the plurality of optical signals utilizing the plurality of photodiodes, communicates the plurality of electrical signals to the plurality of TIAs, amplifies the plurality of electrical signals utilizing the plurality of TIAs, and generates an output electrical signal from coupled outputs of the plurality of TIAs. Each TIA may be configured to amplify signals in a different frequency range. One of the plurality of electrical signals may be DC coupled to a low frequency TIA of the plurality of TIAs.

A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.

A spectrometer and a spectrum measurement method thereof are provided. An analog-to-digital converter converts an amplified signal into a digital signal according to a reference voltage provided by a variable reference voltage generation circuit and amplifies the digital signal according to a target signal value, thereby approximating a signal value of the amplified digital signal to the target signal value. A control circuit outputs a spectral signal according to the amplified digital signal. A user can obtain spectrum measurement results that can be easily interpreted by the spectrometer and the spectrum measurement method thereof, without changing hardware or software, so as to improve convenience of use of the spectrometer.

A receiver circuit, comprising: an receiver-input-terminal configured to receive input-signalling; an receiver-output-terminal configured to provide output-signalling; a plurality of sub-receivers, each configured to compare the received input-signalling with a different effective threshold value in order to provide a digital sub-receiver-output-signal, wherein the different effective threshold values have weighted values in a sequence between a least significant value and a most significant value; a controller configured to, in response to detecting calibration-signalling at the receiver-input-terminal: process the digital sub-receiver-output-signals in order to identify the sub-receiver with the most significant effective threshold value that is triggered by the calibration-signalling as a triggered-sub-receiver; identify a preceding-sub-receiver as the sub-receiver that has an effective threshold value that is before that of the triggered-sub-receiver in the sequence of weighted effective threshold values; and configure the receiver circuit such that, for subsequent signal processing, the sub-receiver-output-signal from the preceding-sub-receiver is provided to the receiver-output-terminal.

A system to program parameters of one or more stages of a transimpedance amplifier (TIA) in an optical sub-assembly (e.g. TO-can package) is disclosed. With this invention, users have the option/flexibility to discretely program any of the stages of the TIA after production of the sub-assembly, i.e. they can still change the TIA settings once the TIA has been installed in a system and the system is in use.

In part, aspects of the invention relate to methods, apparatus, and systems for intensity and/or pattern line noise reduction in a data collection system such as an optical coherence tomography system that uses an electromagnetic radiation source and interferometric principles. In one embodiment, the noise is intensity noise or line pattern noise and the source is a laser such as a swept laser. One or more attenuators responsive to one or more control signals can be used in conjunction with an analog or digital feedback network in one embodiment.