An adaptive equalizer and automatic gain controller is disclosed. The adaptive equalizer and automatic gain controller includes a programmable continuous time linear equalizer (CTLE). The CTLE includes a control port to receive a control signal to adjust a frequency response of the CTLE. The adaptive equalizer and automatic gain controller also includes a power comparator coupled with an output of the CTLE and a controller coupled with the power comparator and the control port and configured to generate the control signal for the CTLE based on the output of the power comparator. The power comparator is configured to compare power of a low frequency part and a high frequency part of an output signal of the CTLE.

An optical receiver can implement a transimpedance amplifier (TIA) to process received light using a closed loop optical pre-amplification. The optical receiver can use an average input value of the TIA to control an semiconductor optical amplifier (SOA) or pre-amplification as received average signal varies. The optical receiver can include a gain controller for the TIA that can measure the TIA swing to adjust the gain of the SOA to pre-amplify received light in a closed loop control configuration.

An optical receiving device includes a conversion module, a signal generation module and a control module. The conversion module performs photoelectric conversion and amplification on an optical signal to generate a photocurrent, the signal generation module provides a gain signal, performs transimpedance and amplification on the photocurrent according to an input signal indicating a preset output voltage swing to generate a voltage signal, and generates a measurement signal indicating an average optical power associated with the optical signal according to the photocurrent, the control module outputs a control signal which is variable to adjust a gain of the conversion module, so that a dynamic range of the conversion module changes as the gain of the conversion module itself changes.

A laser scanner can include a light source to output laser pulses, and an optical sensor to generate analog signals, having a first dynamic range, from light of the laser pulses that is reflected by an object. A logarithmic amplifier can amplify the analog signals to have a second dynamic range that is smaller than the first dynamic range. An analog to digital converter can convert the analog signals to digital signal samples having a signal sample rate. A template can represent an expected return reflection signal, and can have a template sample rate that is higher than the signal sample rate. A processor can perform a cross-correlation between the digital signal samples and the template, determine a time-of-flight value based at least in part on the cross-correlation, and determine a distance to the object based at least in part on the time-of-flight value.

A transimpedance amplifier (TIA) circuit disclosed includes an input terminal, a first TIA circuit, a second TIA circuit, a field effect transistor (FET), and a gain control circuit. The first TIA circuit outputs a voltage signal from a first output in accordance with an input current received at a first input electrically connected to the input terminal. The second TIA circuit outputs a reference signal from a second output. The FET varies a resistance between a first current terminal and a second current terminal in accordance with a control signal applied to a control terminal. The first current terminal is electrically connected to the input terminal. The second current terminal is electrically connected to the second output of the second TIA circuit. The gain control circuit detects an amplitude of the voltage signal and generates the control signal according to a detection result of the amplitude.

A single servo control loop for amplifier gain control based on signal power change over time or system to system, having an amplifier configured to receive an input signal on an amplifier input and generate an amplified signal on an amplifier output. The differential signal generator processes the amplified signal to generate differential output signals. The single servo control loop processes the differential output signal to generates one or more gain control signals and one or more current sink control signals. A gain control system receives a gain control signal and, responsive thereto, controls a gain of one or more amplifiers. A current sink receives a current sink control signal and, responsive thereto, draws current away from the amplifier input. Changes in input power ranges generate changes in the integration level of the differential signal outputs which are detected by the control loop, and responsive thereto, the control loop dynamically adjusts the control signals.

A transimpedance amplifier is provided for converting a current between its two input terminals to a voltage over its two output terminals comprising a high-speed level shifter configured for creating a difference in input DC voltage and for being transparent for alternating voltages, an input biasing network configured for reverse biasing a photodiode connected to at least one of the input terminals and transparent for a feedback signal from the feedback network which is differentially and DC-coupled with the output terminals of the voltage amplifier and outputs of the feedback network are differentially and DC-coupled with the input biasing network of which outputs are coupled with inputs of the level shifter which is differentially and DC-coupled with input terminals of the voltage amplifier.

A linear amplifier includes a pre-amplifier configured to amplify an input differential signal, a post-amplifier configured to amplify an output signal of the pre-amplifier, an amplitude detector configured to detect an amplitude of an output signal of the post-amplifier, and an output voltage corresponding to the detected amplitude, a comparator configured to control a tail current source of the pre-amplifier such that when the output voltage of the amplitude detector is less than or equal to a reference voltage, a tail current of the pre-amplifier is set to a constant value, and when the output voltage of the amplitude detector is larger than the reference voltage, the tail current is reduced to make the output voltage of the amplitude detector equal to the reference voltage.

An optical module includes an optical receiver with a complementary metal-oxide semiconductor (CMOS) transimpedance amplifier (TIA) and a digital signal processing (DSP) circuit. The DSP circuit is integrated with the CMOS TIA and facilitates adaptability of the CMOS TIA, and the CMOS TIA can adapt by using information provided by the DSP circuit.

This application relates to transimpedance amplifier (TIA) apparatus, in particular to a TIA apparatus suitable for receiving data using burst mode communication. The apparatus has a transimpedance amplifier configured to generate a first voltage based on a current at an input node for an input signal. A controlled voltage source, such as a dummy TIA, generates a second voltage based on a first control current. A controller is configured to collectively control the first control current and a second control current based on an indication of input signal magnitude. The first control current controls the second voltage which may be used as a slicing level. The second control current is subtracted from the current at the input node and can provide a DC restore current.