Hitachi, Ltd.

Renesas Technology Corp.

Other

Renesas Electronics Corporation

Hitachi Ulsi Systems Co., Ltd.

Takayuki Iwasaki

Nobuyasu Kanekawa

Masaki Shiraishi

Yasuyuki Kojima

Minehiro Nemoto

Chiyoshi Kamada

Nobuyoshi Matsuura

Tsutomu Yatsuo

Katsuhiro Furukawa

Atsuo Watanabe

Shinichiro Mitani

Seigoh Yukutake

Masatsugu Amishiro

Takayuki Oouchi

Tomoaki Uno

Yoichi Tamaki

Seigou Yukutake

Shin Kimura

Kozo Sakamoto

Kazuhisa Takami

Yusuke Takeuchi

Kousuke Tsuji

Hidekatsu Onose

Toshiyuki Ohno

Yasuo Shima

Toshiyuki Oono

A semiconductor device in which the self-turn-on phenomenon is prevented that can significantly improve power conversion efficiency. The semiconductor device is a system-in-package for power supply applications in which a high-side switch, a low-side switch, and two drivers are included in a single package. The device includes an auxiliary switch disposed between the gate and source of said low-side switch, and a low-side MOSFETfor the low-side switch and an auxiliary MOSFETfor the auxiliary switch are disposed on the same chip. In this way, the self-turn-on phenomenon can be prevented, allowing the mounting of a low-side MOSFETwith a low threshold voltage and thereby significantly improving power conversion efficiency. The gate of the auxiliary MOSFETis driven by the driver for the high-side MOSFET, thereby eliminating the need for a new drive circuit and realizing the same pin configuration as existing products, which facilitates easy replacement.

Semiconductor device, DC/DC converter and power supply

A communication system is provided including a transceiver and an application controller to transmit and receive signals through the transceiver. An isolator which insulates and separates the transceiver and application controller includes primary and secondary side circuits insulated from each other on a substrate and a capacitive insulating means to transfer signals between the primary and second sides while insulating and separating the primary side circuit from the secondary side circuit.

Isolator and a modem device using the isolator

A semiconductor device in which the self-turn-on phenomenon is prevented that can significantly improve power conversion efficiency. The semiconductor device is a system-in-package for power supply applications in which a high-side switch, a low-side switch, and two drivers are included in a single package. The device includes an auxiliary switch disposed between the gate and source of said low-side switch, and a low-side MOSFETfor the low-side switch and an auxiliary MOSFETfor the auxiliary switch are disposed on the same chip. In this way, the self-turn-on phenomenon can be prevented, allowing the mounting of a low-side MOSFETwith a low threshold voltage and thereby significantly improving power conversion efficiency. The gate of the auxiliary MOSFETis driven by the driver for the high-side MOSFETthereby eliminating the need for a new drive circuit and realizing the same pin configuration as existing products, which facilitates easy replacement.

Switch elements and a DC/DC converter using the same

A power MOS-FET is used as a high side switch transistor for a non-insulated DC/DC converter. An electrode section that serves as a source terminal of the power MOS-FET is connected to one outer lead and two outer leads via bonding wires respectively. The outer lead is an external terminal connected to a path for driving the gate. Each of the outer leads is an external terminal connected to a main current path. Owing to the connection of the main current path and the gate driving path in discrete form, the influence of parasitic inductance can be reduced and voltage conversion efficiency can be improved.

Semiconductor device and power supply system

The number of design processes for fabricating semiconductor devices can be reduced by parallel connection of a plurality of unit bipolar transistors Qu that are completely electrically isolated from each other in a semiconductor layer of an SOI substrateto form a bipolar transistor having a large current capacity.

Semiconductor device and method for fabricating the same

The gate resistance of a power MOSFET in a semiconductor chip is reduced and the reliability and yield of the gate of the power MOSFET are improved The semiconductor chip includes two or more control electrode pads functioning as control electrodes for a power semiconductor device formed within a semiconductor chip. The two or more control electrode pads are distributed within the periphery of the gate area of the power semiconductor device such that the gate resistance of the power semiconductor device can be reduced. The two or more control electrode pads are connected via bumps or a conductive bonding material to an electrode layer of a multilayer circuit board disposed outside the semiconductor chip.

Power MOSFET with reduced dgate resistance

In a power supply of a synchronous rectification type, the self-turn on phenomenon of MOSFET is suppressed without increase of the drive loss to thereby improve the power efficiency. In a synchronous rectifier circuit, a threshold value of a commutation MOSFET is made higher than that of a rectification MOSFET and particularly a threshold value of a commutation MOSFETis made 0.5V or more higher than that of a rectification MOSFET. The threshold value of the rectification MOSFETis lower than 1.5V and the threshold of the commutation MOSFETis higher than 2.0V.

Synchronous rectifier circuit and power supply

The number of design processes for fabricating semiconductor devices can be reduced by parallel connection of a plurality of unit bipolar transistors Qu that are completely electrically isolated from each other in a semiconductor layer of an SOI substrate to form a bipolar transistor having a large current capacity.

An isolator is made monolithic by forming a capacitive insulating barrier using an interlayer insulation film on the semiconductor substrate to miniaturize the modem device by the monolithic isolator.

The hardware of an over-sampling A/D and D/A converter is provided, which hardware is capable of being operated with either kind of software: one corresponding to a first method in which the over-sampling ratio is fixed and the other corresponding to a second method in which the over-sampling ratio is variable. The value N written on the pseudo-frequency-dividing-ratio-register and the value N written on the pseudo-over-sampling-ratio-register are converted through a user interface into the frequency dividing ratio N by the conversion circuit and the converted result is written in the frequency-dividing-ratio-register

Over-sampling A/D, D/A converter

The present semiconductor switching device comprises a silicon carbide single crystal of hexagonal symmetry having a first conductive type and a semiconductor region of a second conductive type opposite to the first conductive type and locating in the silicon carbide single crystal. The silicon carbide single crystal of the first conductive type and the semiconductor region of the seconductive type form a pn junction. The pn junction interface has an interface extended in the depth direction from the surface of the silicon carbide single crystal, and the interface includes a crystal plane in parallel to the <11 0> orientation of the silicon carbide single crystal or approximately in parallel thereto, thereby reducing the leak current.

Silicon carbide semiconductor switching device

A wide bandgap semiconductor single crystal is applied as a semiconductor substrate material of a semiconductor surge absorber, and a surge absorption operation starting voltage is set by a punchthrough of a pn junction, to obtain a semiconductor surge absorber with a repetitive operation and a high surge endurance.

Semiconductor surge absorber, electrical-electronic apparatus, and power module using the same

In order to reduce the consumption of power of an isolator interface and an ADC, it is proposed to operate a calling signal reception or Caller ID signal reception function only with power supplied from the system switch while maintaining the on-hook condition of a telephone. At the time of normal operation, the output of the analogue digital converter is input to an isolator through the isolator interface, and at the time of the calling signal reception or the caller identification information reception, the output of the analogue digital converter is input directly to the isolator.

Line interface circuit and information communication apparatus using it

In a silicon carbide static induction transistor, at a surface part of a semiconductor substrate, a p-type gate region is formed partially overlapping a n-type source region, whereby the high accuracy in alignment between the gate region and the source region is not required, and the gate withstand voltage can be highly increased since the substrate is made of silicon carbide, which improves the yield of static induction transistors.

Growing community of inventors

Hitachi, Japan

Takayuki Iwasaki