Hitachi, Ltd.

Renesas Electronics Corporation

Hitachi Metals, Ltd.

Hitachi Astemo Ltd.

Renesas Mobile Corporation

Takayasu Norimatsu

Taizo Yamawaki

Takahiro Nakamura

Satoru Yamamoto

Yukinori Akamine

Koji Maeda

Takao Kihara

Yusuke Wachi

Provided is a technique of power superposition differential data transmission with low radiation noise at low cost and capable of operating at a radio frequency. A differential transmission board superimposes DC power on a differential data signal from a transmission/reception IC and then transmits the signal to a cable, and includes: a first differential transmission line including two wiring patterns; a second differential transmission line including two wiring patterns; two DC transmission lines that transmit the DC power; two capacitor elements that cut off the DC power and pass only the differential data signal; and two inductor elements that cut off a radio-frequency component that is the differential data signal and pass only a DC component, in which the first differential transmission line and the second differential transmission line are connected in series, in which the two capacitor elements are connected in series to the second differential transmission line, in which the second differential transmission line and the DC transmission line are connected via the two inductor elements, and in which a characteristic impedance in a differential mode of the first differential transmission line and a characteristic impedance in the differential mode of the second differential transmission line are substantially equivalent, and a characteristic impedance in an in-phase mode of the second differential transmission line is higher than a characteristic impedance in the in-phase mode of the first differential transmission line.

Differential transmission substrate and power-over-differential data communication device

The equalizer has a first differential pair having a first transistor and a second transistor and a second differential pair having a third transistor and a fourth transistor. A first terminal of the first transistor and a first terminal of the third transistor are connected to each other, and a first terminal of the second transistor and a first terminal of the fourth transistor are connected to each other, so that the first differential pair and the second differential pair have common input terminals. Also, resistors are respectively connected to second terminals of the first, second, third, and fourth transistors, a first zero point generation circuit is connected between the second terminal of the first transistor and the second terminal of the second transistor, and a second zero point generation circuit is connected between the second terminal of the third transistor and the second terminal of the fourth transistor.

Equalizer and equalizing device

Provided is an electric signal transmission device which corrects a data error caused by data transition in a pulse amplitude modulation signal to increase an EYE width. The electric signal transmission device can operate as follows: A data pattern determined by an equalizer and a phase relationship between data and a clock detected by a phase detector are used to calculate a correction amount according to the data pattern and the phase relationship, and the received data is corrected to a correct value by adding a correction amount in a data transition direction.

Electric signal transmission device

An equalizing device has: a low-frequency zero-point circuit having a zero point in a low-frequency band of a before-equalization frequency characteristic of a communication medium; a high-frequency zero-point circuit having a zero point in a high-frequency band of the before-equalization frequency characteristic of the communication medium; and an intermediate-frequency zero-point circuit having a zero point in an intermediate-frequency band present between the low-frequency band and the high-frequency band, wherein an inclination of a waveform of the before-equalization frequency characteristic of the communication medium changes in the intermediate-frequency band; wherein the equalizing device equalizes the signal transmitted through the communication medium so as to restrain an amount of change in an inclination of a waveform of the after-equalization frequency characteristic.

Equalizing device, equalizing method, and signal transmitting device

A decision feedback equalizer of an electric signal transmission apparatus has an average peak value determiner that receives an output of an adder and a threshold value set by a program. An average peak value of the output of the adder), compares a magnitude relation of the detected average peak value and the threshold value, increases the reference value of the output of a reference value generation circuit from an initial value set by the program and causes resolutions of DACs to become coarse from the initial value, when the average peak value is larger than the threshold value, and decreases the reference value of the output of the reference value generation circuit from the initial value set by the program and causes the resolutions of the DACs to become fine from the initial value, when the average peak value is smaller than the threshold value.

Electric signal transmission apparatus

A phase detector, which forms a semiconductor device, detects a phase difference between a reference signal and a feedback signal obtained by feeding back an output signal of an oscillator, and generates a phase difference value indicating a value in accordance with the phase difference. An amplifier amplifies the phase difference value at a gain determined in accordance with a control signal from outside the device. A filter smoothes an output value of the amplifier. The oscillator controls a frequency of the output signal in accordance with an output value of the filter.

Semiconductor device and radio communication terminal mounting the same

The transmitter synthesizes amplitude and phase components and calibrates a delay mismatch between amplitude and phase components with high accuracy at high speed. The transmitter has: a digital-to-analog converter (DAC) and a low-pass filter (LPF) in its amplitude-signal path; and a phase modulator operable to convert up a phase component into an RF component in its phase-signal path. In an operation of delay calibration, a test input signal is supplied to a delay-calibrating unit in the amplitude-signal path, and the delay-calibrating unit provides a test input signal to DAC. Then, LPF generates a test output signal. The delay-calibrating unit detects a delay of the test output signal relative to the test input signal, calibrates an amplitude signal delay in a range from the input of the delay-calibrating unit to the output of LPF, reduces the difference between amplitude and phase signal delays of the phase modulator in the phase-signal path.

Transmitter and semiconductor integrated circuit available for it

A quadrature modulator has first to fourth transistors, a first node, a second node, and a first output node. A non-inversion in-phase analog signal, an inversion in-phase analog signal, a non-inversion quadrature analog signal, and an inversion quadrature analog signal are supplied to input electrodes of the first to fourth transistors, respectively. Control electrodes of the first to fourth transistors respond to a non-inversion in-phase RF signal, an inversion in-phase RF signal, a non-inversion quadrature RF signal, and an inversion quadrature RF signal, respectively. Output electrodes of the first and second transistors are coupled to the first node, and output electrodes of the third and fourth transistors are coupled to the second node. A first high-pass filter is coupled between the first node and the first output node, and a second high-pass filter is coupled between the second node and the first output node.

Growing community of inventors

Tokyo, Japan

Takayasu Norimatsu