Abstract:
PROBLEM TO BE SOLVED: To provide a distributed amplifier having a tapered transconductance architecture. SOLUTION: The distributed amplifier having an improved transimpedance and/or gain is provided with an input transmission line and an output transmission line, the input transmission line forms the input of the distributed amplifier and has a characteristic impedance associated therewith, and the output transmission line forms the output of the distributed amplifier and has a characteristic impedance associated therewith. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a method and a device for locking and unlocking of an adaptive cache frame. SOLUTION: A frame that has been most accessed of late in a cache memory is possible to be accessed again by a task in the near future. By locking these frames that have been most used at the start of switch or interrupt of a task, the cache performance is improved. The list of frames that have been most used of late is updated as the task is executed, and the list is realized as a list of frame addresses or a flag related to each frame. An adaptive frame unlocking mechanism is also disclosed that automatically unlocks a frame being a potential primary factor of remarkable performance deterioration for a task. The adaptive frame unlocking mechanism monitors the number of times of frame errors that the task makes, and, if the number of times of frame errors exceeds a given threshold, unlocks a given frame. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a light source driver equipped with a bias circuit for controlling an output overshoot. SOLUTION: A driving circuit for a laser diode or another light source is provided with a differential circuit having a first and a second input for receiving differential input data, a current generator circuit for producing a modulation current for a light source while answering to the input data, and a variable bias circuit for adding a variable bias to the differential circuit. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide an optical receiver including a single integrated device capable of substantially simultaneously performing demultiplexing and clock recovery of high-speed OTDM signals in excess of 40 Gbps. SOLUTION: Simultaneous demultiplexing and clock recovery of high-speed (e.g. 80 Gbps or 160 Gbps) optical time division multiplex (OTDM) signals is achieved using a tandem electro-absorption modulator (TEAM). The TEAM has a monolithically integrated SOA (Semiconductor Optical Amplifier) to compensate the insertion loss and two EAMs to reduce the switching window. The demultiplexing and clock recovery may be performed by a single TEAM, or by two or more TEAMs. A fiber Raman amplifier may be used to boost the intensity of the OTDM signals during transmission.
Abstract:
PROBLEM TO BE SOLVED: To provide a comparator with non-complementary input structure in order to improve technical problems such as power consumption, number of transistors and a throughput delay in a conventional comparator circuit with a complementary input structure. SOLUTION: The non-complementary comparator includes an evaluation element such as a memory cell, a differential amplifier, or another type of circuit capable adapted to perform an evaluation function, and at least first and second input legs each coupled to a corresponding one of a first and second node of the evaluation element. However, after the evaluation, the output attains a full digital value but suffers no defective power consumption. Transistors form a cross coupling random access memory cell and perform a comparison of contents of the two legs during the evaluation. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a high speed photodetector having both excellent optical coupling efficiency and high internal efficiency. SOLUTION: This optical device is provided with a first waveguide 204 having a capability for supporting an optical mode. The optical mode has a first size in the inside of the first waveguide 204. The first waveguide 204 is optically coupled to a second waveguide 207. The second waveguide 207 has a capability for supporting the optical mode and the optical mode has a second size in the inside of the second waveguide 207. The photodetector is optically coupled to the second waveguide 207. As a strong point, the first mode size is larger than the second mode size. The first waveguide 204 is capable of being efficiently coupled to an optical source, for example, an optical fiber. The second waveguide 207 is capable of being efficiently coupled to the detector.
Abstract:
PROBLEM TO BE SOLVED: To provide a semiconductor device which is manufactured by the use of organic material having bipolar charge transfer characteristics. SOLUTION: The active layer of a field-effect transistor is formed of organic semiconductor material having bipolar charge transfer characteristics. The semiconductor material is formed of a bipolar polymer film which is effective for the transfer of holes or electrons, containing polymer that has a conjugate skeleton stare possessed of a functional part capable of promoting the transfer of ionic charge. The conjugate skeleton is selected out of thiophene, pyrrole, benzene, naphthalene, anthracene and anthracene-dione, and the functional part is selected out of (i) a functional group containing calboxylate and sulfonate and (ii) a functional site selected from dissimilar atoms provided with isolated electron pairs, containing sulfur, nitrogen, and oxygen. The field effect mobility of the bipolar polymer film is, at least, as high as 10-3 cm2/Vs when it operates as an N-type or a P-type device.
Abstract:
PROBLEM TO BE SOLVED: To provide a method of forming Pb-free solder bumps with improved mechanical properties and to provide a semiconductor device using the same.SOLUTION: There is provided a semiconductor substrate having a first contact and an undoped electroplated lead-free solder bump 610 formed on the first contact. There is also provided a device package substrate having a second contact and a doped lead-free solder layer 510 containing dopant on the second contact. The dopant reduces a solidification undercooling temperature of the undoped lead-free solder bump when the dopant is incorporated into the lead-free solder bump. The undoped electroplated lead-free solder bump and the doped lead-free solder layer are melted thereby incorporating the dopant into the undoped lead-free solder to form a doped solder bump 140. The solder bump provides an electrical connection between the first contact and the second contact.
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatus for storing data in a multi-level cell flash memory device with cross-page sectors, multi-page coding and per-page coding.SOLUTION: A single sector can be stored across a plurality of pages in the flash memory device. Per-page control is provided of the number of sectors in each page, as well as a code and/or code rate used for encoding and decoding a given page, and a decoder or decoding algorithm used for decoding a given page. A multi-page access scheme and a wordline level access scheme are also provided.
Abstract:
PROBLEM TO BE SOLVED: To provide an integrated circuit having a monitor circuit for monitoring timing in a critical path having a target timing margin.SOLUTION: The monitor circuit comprises two shift registers, one of which includes a delay element that applies a delay value to a received signal. The inputs to the two shift registers form a signal input node capable of receiving an input signal. The monitor circuit also has a logic gate having an output and at least two inputs, each input connected to a corresponding one of the outputs of the two shift registers. The output of the logic gate indicates whether the target timing margin is satisfied or not satisfied.