Sumitomo Electric Industries, Limited

Naoki Itabashi

Keiji Tanaka

Taizo Tatsumi

Yoshiyuki Sugimoto

Hiroshi Hara

Makoto Ito

Tomoya Saeki

Naoya Kono

Chie Fukuda

Yasuyuki Yamauchi

Kazuhiro Yamaji

Masataka Watanabe

Morihiro Seki

Kosuke Okawa

An optical semiconductor module according to the embodiment includes: a board including a transmission line; a block including a low-permittivity material; an inductor mounted on the block, the inductor being connected with the transmission line via a first wire, the first wire having a first inductance; a semiconductor laser device mounted on the board, the semiconductor laser device being connected with the transmission line via a second wire, the second wire having a second inductance smaller than the first inductance; and a housing configured to accommodate the board, the block, the inductor, and the semiconductor laser device.

Optical semiconductor module

An optical semiconductor module according to an embodiment includes a housing; a temperature control element having a temperature control plane; a first board mounted on the temperature control plane; a semiconductor laser device mounted on the second side of the first board; a second board mounted on the second side of the first board, the second board having a third side and a fourth side, the fourth side including a wiring pattern, the wiring pattern being electrically connected with the housing via a first bonding wire and electrically connected to the semiconductor laser device via a second bonding wire, the second board having a second thermal conductivity smaller than the first thermal conductivity. The housing is configured to accommodate the temperature control element, the first board, the second board, and the semiconductor laser device.

An optical module includes a circuit board having a through hole for the lead terminal, a signal wiring connected to the lead terminal, a ground layer providing a reference potential, an opening through which the ground layer is exposed, and a bonding material connecting the ground layer to the metallic base. The lead terminal extends in a first direction, and the circuit board and the signal wiring extend in a second direction. When the circuit board is viewed from the first direction, the opening overlaps with the signal wiring, or when the opening does not overlap with the signal wiring, a first distance between the signal wiring and a closest point of the opening to the signal wiring is smaller than a second distance between the closest point and an edge of the circuit board.

Optical module and manufacturing method of the same

An optical receiver disclosed includes a bias terminal, an input terminal, a photodiode, an amplifier circuit, a first resistor, a bypass circuit, a filter circuit, and a control circuit. The photodiode receives a bias from the filter circuit through the bias terminal, and outputs a current signal to the amplifier circuit through the input terminal. The amplifier circuit converts an input current to an output voltage. The bypass circuit electrically connected to the input terminal decreases a first input impedance viewed from the input terminal, when activated, and increases the first input impedance, when deactivated. The filter circuit increases a second input impedance viewed from the bias terminal, when a dumping function thereof is activated, and decreases the second input impedance, when the dumping function is deactivated. The control circuit activates the dumping function and the bypass circuit, when the output voltage is larger than a certain voltage.

Optical receiver and transimpedance amplifier circuit

A differential amplifier circuit includes a first transistor, a second transistor, a field effect transistor (FET) connected between the first transistor and the second transistor, a first current source connected to the first transistor, a second current source connected to the second transistor, and a control circuit. The first transistor and the second transistor generate a differential output signal in accordance with an input signal and a reference signal. The control circuit includes a first resistor and a second resistor connected in series between the drain and the source of the FET, a center node between the first resistor and the second resistor, a third resistor connected between the gate of the FET and the center node, and a variable current source. The variable current source supplies a control current to the third resistor in accordance with a gain control signal. The control circuit controls on-resistance of the FET.

Differential amplifier circuit having variable gain

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.

Transimpedance amplifier circuit

An amplifier includes a printed circuit board that includes an output terminal for outputting an electrical signal to an outside and a bias terminal for receiving a bias of the electrical signal from the outside, and an integrated circuit, a capacitor, an inductor, and a ferrite bead element mounted on the printed circuit board. The integrated circuit includes a driving circuit and an output end, and outputs the electrical signal generated by the driving circuit from the output end. The capacitor is connected between the output end and the output terminal. A series circuit includes the inductor and the ferrite bead element connected to each other in series, with the inductor connected to the output end, and the ferrite bead element connected to the bias terminal.

Amplifier and optical transmitter using the same

A transimpedance amplifier includes a variable gain circuit configured to generate a pair of complementary signals in accordance with an input signal and a reference signal. A first differential circuit of the variable gain circuit includes a first transistor including a control terminal to receive the input signal, a second transistor including a control terminal to receive the reference signal, and a variable resistance circuit including a first field effect transistor (FET) and a second FET. A first timing when a voltage of a first linearity adjustment signal input to the first FET reaches a first threshold voltage of the first FET and a second timing when a voltage of a second linearity adjustment signal input to the second FET reaches a second threshold voltage of the second FET are different from each other.

Variable gain circuit and transimpedance amplifier using the same

An LD driver circuit includes an adjustment circuit to which a power supply voltage is applied. The adjustment circuit receives an input signal through an input terminal, generates a shifted input signal shifted in voltage from the input signal by a predetermined shift amount, and outputs the shifted input signal from an output terminal. The LD driver circuit also includes a transistor with its base receiving the shifted input signal, its collector electrically connected to an anode of a driven LD, and its emitter electrically connected to a cathode of the LD and ground, which transistor varies an amount of a shunt current flowing from the collector to the emitter in accordance with the shifted input signal. The adjustment circuit includes a comparator which compares a voltage in the collector and a threshold voltage, and increases or decreases the predetermined shift amount in accordance with an output of the comparator.

Laser driver circuit and optical transmitter using the same

A circuit device includes a differential circuit including differential input terminals; a differential amplifier circuit in which differential input nodes are connected to the differential input terminals; a first power supply terminal supplied with a first voltage; a second power supply terminal supplied with a second voltage; a common terminal; a first resistive element of which one end is connected to one differential input terminal and another end is connected to the common terminal; a second resistive element of which one end is connected to the first supply terminal and another end is connected to the common terminal; a third resistive element of which one end is connected to one differential input terminal and another end is connected to the second supply terminal; a bonding wire, and a capacitor of which one end is connected to the second supply terminal and another end is connected to the common terminal.

Integrated circuit device

A variable gain amplifier capable of stabilizing an average output potential of a differential output signal, improving power efficiency over a wide range of an amplitude of the differential input signal, and suppressing deterioration of a distortion rate is provided. The variable gain amplifier includes an amplifying circuit configured to amplify a differential input signal with a gain according to a gain control signal, and a current control circuit. The amplifying circuit has a first current source supplying a source current. The current control circuit adjusts a magnitude of the source current of the first current source according to a magnitude of the gain control signal.

Variable gain amplifier

An amplifier including a pre-amplifier, an impedance converter, and a traveling wave amplifier (TWA) is disclosed. The pre-amplifier receives a differential input signal and has a pair of first output nodes that output a first differential signal by amplifying the differential input signal. Each first output node has first output impedance. The impedance converter includes a pair of first input nodes that receive the first differential signal and a pair of second output nodes that output a second differential signal. Each first input node has first input impedance greater than the first output impedance. The impedance converter converts the first differential signal into the second differential signal. Each second output node has second output impedance smaller than the first output impedance. The TWA includes a pair of transmission lines connected to the pair of the second output nodes. Each transmission line has characteristic impedance matching with the second output impedance.

Amplifier

A traveling-wave amplifier includes a plurality of amplifier cells, an insulating layer, an input line, and an output line. The plurality of amplifier cells is provided on a semiconductor substrate. Each of the amplifier cells receives an input signal and generates a part of an output signal from the input signal. The insulating layer is provided on the semiconductor substrate. The input line is used to externally receive an input signal and to transmit the input signal to the amplifier cells respectively. The output line is used to transmit the output signal generated by the amplifier cells and to externally output the output signal. The thickness of the input line is smaller than the thickness of the output line, and the input line and the output line are provided on the same insulating layer.

Traveling-wave amplifier

A differential amplifier includes an amplifying stage that outputs an output signal by amplifying an input signal with a gain set by a control signal, and an adjusting stage that stabilizes a DC level of the output signal. The amplifying stage includes a first source supplying a first current, and a load, and determines a ratio of a current flowing through the load to the first current depending on the input signal and the control signal, and generates the output signal from a voltage drop of the load. The adjusting stage includes a second source supplying a second current, and a monitor resistor, and generates a monitor current divided from the second current by the ratio, and duplicates the DC level as a voltage drop of the monitor resistor caused by the monitor current, and controls the first current source and the second current source depending on the DC level.

Differential amplifier

An amplifier circuit has: a main amplifier connected between an input terminal and an output terminal, the main amplifier amplifying an input signal input to the input terminal and outputting an amplified signal to the output terminal; a compensation circuit comprising a variable delay circuit and a variable gain inverting circuit, the variable delay circuit receiving the input signal and outputting a delay signal with a delay time from the input signal, the variable gain inverting circuit inverting and amplifying the delay signal with a gain and outputting a compensation signal to the output terminal; and a controller configured to control the gain of the variable gain inverting circuit and the delay time of the variable delay circuit to compensate a response of the main amplifier in a first frequency of a target signal of compensation and in a low frequency band higher than zero Hertz.

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Yokohama, Japan

Naoki Itabashi