Patent classifications
H04B10/693
Amplifier
An amplifier applied to TIA is provided to suppress the noise caused by a current source. An amplifier constituting a transimpedance amplifier includes an inductor element inserted between a current source connected to an input terminal of an amplification stage and a power source voltage line. The current source includes a first transistor in which a base terminal is connected to a current control bias and a collector terminal is connected to the input terminal. The inductor element is inserted between the emitter terminal of the first transistor and the power source voltage line.
Optical receiver
The present disclosure relates to optical receivers. One example optical receiver includes an optoelectronic detector, a transimpedance amplification (TIA) circuit, a single-ended-to-differential converter, an I/O interface, and a controller. The optoelectronic detector, having bandwidth lower than required system transmission bandwidth, converts an optical signal into a current signal. The TIA circuit compensates gain for the received current signal based on a received control signal to obtain a voltage signal, where a frequency response value of the current signal within first bandwidth is greater than that within the bandwidth of the optoelectronic detector, and any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector. The single-ended-to-differential converter converts the voltage signal into a differential voltage signal. The I/O interface outputs the differential voltage signal. The controller generates the control signal based on the differential voltage signal.
High dynamic range analog front-end receiver for long range LIDAR
A system and method for operating a high dynamic range analog front-end receiver for long range LIDAR with a transimpedance amplifier (TIA) include a clipping circuit to prevent saturation of the TIA. The output of the clipping circuit is connected via a diode or transistor to the input of the TIA and regulated such that the input voltage of the TIA remains close to or is only slightly above the saturation threshold voltage of the TIA. The regulation of the input voltage of the TIA can be improved by connecting a limiting resistor in series with the diode or transistor. A second clipping circuit capable of dissipating higher input currents and thus higher voltages may be connected in parallel with the first clipping circuit. A resistive element may be placed between the first and second clipping circuits to further limit the input current to the TIA.
Self biased dual mode differential CMOS TIA for 400G fiber optic links
A transimpedance amplifier (TIA) device. The device includes a photodiode coupled to a differential TIA with a first and second TIA, which is followed by a Level Shifting/Differential Amplifier (LS/DA). The photodiode is coupled between a first and a second input terminal of the first and second TIAs, respectively. The LS/DA can be coupled to a first and second output terminal of the first and second TIAs, respectively. The TIA device includes a semiconductor substrate comprising a plurality of CMOS cells, which can be configured using 28 nm process technology to the first and second TIAs. Each of the CMOS cells can include a deep n-type well region. The second TIA can be configured using a plurality CMOS cells such that the second input terminal is operable at any positive voltage level with respect to an applied voltage to a deep n-well for each of the plurality of second CMOS cells.
Signal Detection for GPON Optical Line Terminal
A signal detection circuit has a first differential amplifier including a first input coupled for receiving a data signal, and a second input coupled for receiving a threshold signal. A current steering circuit is coupled to an output of the first differential amplifier to establish a threshold for the first differential amplifier. A latch has an input coupled to the output of the first differential amplifier for latching a signal detect. A second amplifier has an input coupled to the output of the first differential amplifier and an output coupled to the input of the latch. A third amplifier has an input coupled to the output of the first differential amplifier and an output providing the data signal. The current steering circuit can be disabled which removes the need for the third amplifier as the data signal path is through second amplifier.
Low power optical link
An optical receiver circuit is disclosed, including a photodiode, an output terminal, a first amplifier stage, and an electrostatic discharge (ESD) protection circuit. The photodiode may generate a receiver current based on received optical signals. The first amplifier stage may be coupled between the photodiode and the output terminal and include a first inductor coupled between the photodiode and an input of a first inverter, and a second inductor coupled between the input of the first inverter and a first resistor. The first resistor may be coupled between the second inductor and an output of the first inverter. ESD protection circuit may be coupled to the input of the first inverter. The output terminal may generate an output signal based at least in part on the output of the first inverter.
Optical receiver
An optical receiver includes a transimpedance amplifier that converts a current signal corresponding to an optical signal into a voltage signal. The transimpedance amplifier includes an input terminal receiving the current signal, an output terminal outputting the voltage signal, an inverting circuit including a pull-up device that pull-up drives the voltage signal of the output terminal according to the current signal, and a pull-down device that pull-down drives the voltage signal of the output terminal according to the current signal, a feedback resistor electrically connected between the input and output terminals, a first resistor electrically connected between the input terminal and the pull-up device, and a second resistor electrically connected between the input terminal and the pull-down device.
Bias circuit with a replica circuit for an amplifier circuit and a generation circuit supplying bias voltage to the replica and amplifier circuits and optical receiver
A bias circuit includes a replica circuit for an amplifier circuit using a cascode type inverter, and a generation circuit that generates a bias voltage that causes a drain voltage of an input stage transistor of the amplifier circuit to be a saturation drain voltage, based on an output voltage of the replica circuit, and supplies the generated bias voltage to a cascode element of the amplifier circuit and a cascode element of the replica circuit.
Optical receiver
An optical receiver includes a light receiving element array that includes a plurality of light receiving elements, a plurality of amplifiers that amplify respective currents obtained by the plurality of light receiving elements, a plurality of anode lines arranged in a region between the light receiving element array and the plurality of amplifiers, the plurality of anode lines coupling respective anodes of the plurality of light receiving elements to the plurality of amplifiers, respectively, and a cathode line disposed in a region different from the region between the light receiving element array and the plurality of amplifiers, the cathode line coupling respective cathodes of the plurality of light receiving elements to a bias power supply and a bypass capacitor.
OPTICAL MODULE
The present disclosure provides an optical module comprising: a photoelectric conversion unit, a first demodulation circuit, and a second demodulation circuit; the first demodulation circuit and the second demodulation circuit are respectively connected to the photoelectric conversion unit; the photoelectric conversion unit is configured to convert the received optical signal into an electrical signal; the first demodulation circuit is configured to demodulate an electrical signal converted by the photoelectric conversion unit and generate a high-frequency electrical signal; the second demodulation circuit is configured to demodulate an electrical signal converted by the photoelectric conversion unit and generate a low-frequency electrical signal.