Seiko Instruments Inc

Other

Nec Corporation

Minoru Sudo

Yoshikazu Kojima

Hiroshi Mukainakano

Sadashi Shimoda

Takayuki Takashina

Kazuaki Sawada

Makoto Ishida

Hidekuni Takao

Jun Osanai

Takashi Niwa

Kenji Kato

Norio Chiba

Susumu Ichihara

Mitsuo Yarita

Toshiya Shimura

Provided is an ESD protection circuit for CDM capable of preventing a high current from flowing and preventing breakage when a battery is connected with reverse polarity. The ESD protection circuit employs a circuit configuration in which transistor elements are interposed in series to OFF transistors (and) included in the ESD protection circuit for CDM so that parasitic diodes of the transistor elements are connected to parasitic diodes of the OFF transistors in a reverse direction.

Method of manufacturing a package

Provided is a voltage regulator capable of preventing a large current from flowing even when a battery () is connected with reverse polarity by mistake. The voltage regulator employs a circuit configuration in which a substrate potential (n-well) of an output transistor () of the voltage regulator is not fixed to a potential of a VDD terminal, and a power supply of a reference voltage circuit () and an error amplifier () is not fixed to the VDD terminal.

Voltage regulator

A power generation circuit has one of an antenna or a coil that receives an ambient radio wave. A rectifying circuit is connected to the antenna or the coil for rectifying a signal from the antenna or the coil receiving the ambient radio wave. A booster circuit is connected to and boosts an output of the rectifying circuit. A storage circuit is connected to the booster circuit and stores an output power obtained from the rectifying circuit for driving a load without the use of a power source or a battery. A switching circuit is operable in an ON-state thereof to connect the storage circuit to the load when a voltage of the storage circuit is equal to or greater than a preselected voltage.

Power generation circuit for generating and storing electric power utilizing radio wave energy

A power generation circuit generates and stores electric power utilizing electromagnetic wave energy. The power generation circuit has one of an antenna or a coil that receives an electromagnetic wave. A rectifying circuit is formed on a silicon substrate and rectifies a signal from the antenna or the coil. A storage circuit stores an output power obtained from the rectifying circuit for driving a load. A MOS transistor has a source and a drain connected to an output of the storage circuit and the load, respectively, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor.

Power generation circuit using electromagnetic wave

An electronic circuit device comprises a silicon substrate having front and rear surfaces, a semiconductor element formed on the front surface, and at least one through-hole penetrating through the front surface and the rear surface. At least one passive element is supported by the silicon substrate. At least one connecting element is disposed in the through-hole of the silicon substrate for electrically connecting the semiconductor element to the passive element.

Electronic circuit device having silicon substrate

Provided is a humidity sensor whose electrode is set to have an island-like configuration and is enclosed by a humidity sensitive film. As a result, in the humidity sensor, adhesion property between the humidity sensitive films on the electrode is enhanced and thus high reliability is achieved.

Humidity sensor and semiconductor device including the same

A system for measuring the transmission characteristic of an xDSL system that implements high-speed data communication over existing copper telephone wires connecting an office and a subscriber includes a polling device included in the outside line of an xDSL circuit, which is installed in an office, for polling a subscriber line. A noise level measuring circuit measures the existing level of cross-talk noise on the subscriber line. A decision circuit determines, based on the existing level of cross-talk noise measured, whether or not the subscriber line is usable.

Method of measuring and improving xDSL transmission characteristic

A capacitance type dynamic quantity sensor has a first substrate, a second substrate disposed over the first substrate, and first and second electrodes each disposed on a main surface of a respective one of the first and second substrates. Each of the first and second electrodes has through-holes formed in a portion thereof. A third substrate is disposed between and connected to the main surface of each of the first and second substrates. A vibration member is mounted on the third substrate so as to confront the first and second electrodes with gaps therebetween. The vibration member is mounted on the third substrate to undergo vibrational movement in response to application of an acceleration or an angular velocity to the vibration member so that the capacitance type dynamic quantity sensor detects a dynamic quantity in accordance with a change in capacitance between the first and second electrodes due to vibrational movement of the vibration member.

Capacitance type dynamic quantity sensor

A battery pack has a secondary battery connected to a plus side terminal. A protective circuit protects the secondary battery from overcharge and over-discharge. A calculation circuit operates with a minus side terminal as a reference for calculating a remaining capacity of the secondary battery. An N-channel MOS transistor is connected between the secondary battery and the minus terminal for controlling charge and discharge of the secondary battery in accordance with a signal from the protective circuit. A level shifter circuit is connected between the calculation circuit and a communication terminal.

Battery pack with a remaining battery power calculating function

An LED drive circuit having reduced power consumption has a constant current generating circuit for driving a plurality of LEDs and at least one switch connected to a respective LED for periodically turning on and off the respective LED at a rate higher than a visual perception rate to reduce power consumption.

LED drive circuit

In order to improve drive performance of a voltage regulator (on resistance of an output transistor) while suppressing increases in surface area resistance of an output transistor is reduced by changing the threshold voltage of the output transistor by controlling the back-gate voltages of output transistors of a voltage regulators.

Voltage converter having switching element with variable substrate potential

When an output impedance of an input power supply for a switching regulator is high, damages caused by a large current are suppressed which are given to switch elements employed in a power supply circuit and the switching regulator. In a step-up type switching regulator control circuit comprising at least an error amplifying circuit and a drive circuit of a switch element and producing an output voltage higher than an input voltage, the error amplifying circuit is operated by the input voltage; the drive circuit of the switch element is operated by the output voltage; the step-up type switching regulator control circuit is further comprised of a voltage detecting circuit operated by the output voltage; the voltage detecting circuit detects the input voltage, and when the input voltage is decreased lower than an arbitrary voltage, the voltage detecting circuit causes the drive circuit of the switch element to produce such a signal capable of firmly turning OFF the switch element.

Switching regulator control circuit avoiding break-down of the switching element

In order to avoid a ripple voltage and to ensure that an adequate voltage is applied to a load even when a supply voltage is low, the duty ratio of a PFM type switching regulator is provided with a supply voltage dependency. A control circuit for a PFM type switching regulator according to a first embodiment comprises a first circuit for producing a first output signal based on a difference between a fed back portion of a regulated output voltage of a PFM type switching regulator and a first reference voltage; and a second circuit for producing a second output signal based on a second reference voltage, the second output signal being used for modulating the first output signal and including a pulse signal having successive pulses the width of which is dependent upon the value of the second reference voltage so that the duty cycle of the PFM type voltage regulator is dependent upon the second reference voltage. The second reference voltage varies depending upon the value of a power supply voltage of the PFM type switching regulator so that the duty ratio is increased when the power supply voltage decreases and the duty ratio decreases when the power supply voltage increases.

Switching regulator control circuit of PFM system and switching regulator thereof

A synchronous rectifying type switching regular circuit operable in a high efficiency is obtained, while a reverse current flowing through a coil is not used to charge a power supply. In a synchronous rectifying type switching regulator circuit for alternately turning ON/OFF a first switch element for controlling a current of a coil employed in the switching regulator and a second switch element connected parallel to a commutation diode, a capacitor is added to an input of the switching regulator circuit; a third switch element is interposed between a power supply such as a battery and the capacitor; and when the first switch element is turned ON, the third switch element is turned ON, whereas when the first switch element is turned OFF, the third switch element is turned OFF.

Growing community of inventors

Chiba, Japan

Minoru Sudo