Examples described herein relate to calibration of an optical communications link. Data signals received over the optical communications link are measured to obtain an eye scan. A height of an upper eye region and a height of a lower eye region are compared in the eye scan. A common mode calibration value is adjusted based on any difference in the heights. A common mode adjustment circuit is then controlled based on the common mode calibration value. The common mode adjustment circuit is configured to remove a direct current bias within a receiver for the optical communications link.

Examples described herein relate to calibration of an optical communications link. Data signals received over the optical communications link are measured to obtain an eye scan. A height of an upper eye region and a height of a lower eye region are compared in the eye scan. A common mode calibration value is adjusted based on any difference in the heights. A common mode adjustment circuit is then controlled based on the common mode calibration value. The common mode adjustment circuit is configured to remove a direct current bias within a receiver for the optical communications link.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

A mobile visible light communication (VLC) receiver and associated method of use which overcomes the detrimental effects of the time-varying inter-symbol interference (ISI) due to the VLC receiver's high acceptance angle and vibration in the structure utilizing an optimal multiple-symbol detection (MSD) module and a decision feedback affine projection algorithm (DF-APA) module.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

A signal processing apparatus, an optical line terminal, and a communications system are provided. The signal processing apparatus includes a signal input interface, a signal output interface, a reset signal generation unit, a signal amplification and equalization unit, an enable signal generation unit, and N direct-current offset calibration loop units. The signal input interface is connected to the signal amplification and equalization unit, which is connected to the signal output interface and the enable signal generation unit; the enable signal generation unit is connected to the N direct-current offset calibration loop units, which are connected to the signal amplification and equalization unit; and the reset signal generation unit is connected to the N direct-current offset calibration loop units. Embodiments of the present invention are directed to reduce an LA burst settling time, thereby reducing physical overheads of a link.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

A circuit and method in an amplifier circuit for filtering a DC offset in differential input signals and inserting a programmable adjustable crosspoint offset in differential output signals. An amplifier circuit includes a differential amplifier circuit configured to amplify differential input signals into differential output signal. The amplifier circuit further includes a feedback circuit coupled between the differential output signals and the differential input signals. The feedback circuit is configured to generate a programmably adjustable crosspoint offset in the differential output signal and a programmably adjustable cutoff frequency of the feedback circuit. An amplifier method includes amplifying differential input signals into differential output signals, generating a programmably adjustable crosspoint offset in the differential output signal, and generating a programmably adjustable cutoff frequency of a feedback circuit between the differential output signals and the differential input signals.

This invention relates to a optical receiver circuit (200) comprising: at least one photo detector (207) configured to convert a received light signal to an input current signal, a transimpedance amplifier circuit (201) with an input to receive the input current signal from the at least one photo detector (207) and being configured to convert the received input current signal to an output voltage signal to generate an output signal of the transimpedance amplifier circuit (201), wherein the transimpedance amplifier circuit comprises a plurality of gain amplifier stages (209, 210, 211), a DC restoration component (205), wherein the DC restoration component (205) is configured to receive the output voltage signal of the transimpedance amplifier circuit (201) for restoring the DC component of the received current signal and configured for outputting a corresponding current signal, and an automatic gain control component (204) configured for controlling via at least one programmable feedback resistor (226, 227) the equivalent transimpedance of the transimpedance amplifier circuit based on the signal output by the DC restoration component (205) to provide a constant output voltage amplitude for different current ranges of the input current signal.

An example of an isolation sensor package is disclosed to include a first Integrated Circuit (IC) chip and a second IC chip. The first IC chip may include an input interface circuit that receives an input signal from a first input signal terminal and a second input signal terminal, where the input signal ranges between a first positive voltage and a first negative voltage. The first IC chip may further include a negative voltage generator that generates a second negative voltage, a level shifter that receives an output of the input interface circuit and generates a modified signal having a voltage level between a ground voltage provided to the ground terminal and a second positive voltage that is present at a voltage supply terminal. The first IC chip may further produce a signal based on the modified signal generated by the level shifter.