Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Texas Instruments Corporation

Kabushiki Kaisha Toyota Chuo Kenkyusho

Kabushiki Kaisha Toyoda

Shinobu Aoki

Haruo Takagi

Tetsuo Tateishi

Hiroshi Tadano

Hiroto Tanaka

Takashi Suzuki

Yukihiko Watanabe

Shogo Mori

Takanori Okabe

Susumu Sugiyama

A method for a DC to DC converter with a pseudo constant switching frequency is disclosed herein. For example, some embodiments provide a DC to DC converter having a switch connected to a switching node to control a voltage of the switching node, and a switching controller that is adapted to turn on and off the switch at a substantially constant frequency based at least in part on the voltage of the switching node. The switching controller includes a modulator connected to a control electrode of the switch and that is adapted to actuate and deactuate the switch, and a first timer that is connected to the switching node and to the modulator. The first timer uses the voltage of the switching node to determine an on-time for the switch.

DC to DC converter with pseudo constant switching frequency

Various apparatuses, methods and systems for a DC to DC converter with a pseudo constant switching frequency are disclosed herein. For example, some embodiments provide a DC to DC converter having a switch connected to a switching node to control a voltage of the switching node, and a switching controller that is adapted to turn on and off the switch at a substantially constant frequency based at least in part on the voltage of the switching node. The switching controller includes a modulator connected to a control electrode of the switch and that is adapted to actuate and deactuate the switch, and a first timer that is connected to the switching node and to the modulator. The first timer uses the voltage of the switching node to determine an on-time for the switch.

A comparator monitors an output voltage V.sub.out. When an output voltage V.sub.out decreases to a predetermined output voltage or less, the comparator sends a signal that represents this state to a controlling circuit. When the controlling circuit receives the signal, it causes a switching device to be turned on. Thus, a coil current I.sub.L is increased. A hysteresis (window) comparator monitors the coil current I.sub.L. When the coil current I.sub.L reaches a comparison current I.sub.LP, the controlling circuit causes the switching device to be turned off. When the coil current I.sub.L decreases to the comparison current I.sub.LB (where I.sub.LP &gt;I.sub.LB), the controlling circuit references an output signal of the comparator. When the output voltage V.sub.out is lower than the predetermined output voltage, the controlling circuit causes the switching device to be turned on.

DC/DC converter with multiple operating modes

A DC/DC converter generates a voltage required by a load. A battery supplies electric power for the load as necessary. A charging circuit charges the battery. The load, the DC/DC converter, the battery, and the charging circuit are contained in a housing. The charging circuit controls a charging current to be supplied for the battery such that a total consumed electric power (a sum of electric power consumed by the load, the DC/DC converter, and the charging circuit) dose not exceed the allowable dissipation of the housing.

Circuit and method for charging a battery based on an allowable

DC/DC converter with reduced power consumpton and improved efficiency

A static induction type semiconductor device of a surface gate type, includes a source region, gate region and drain region. A channel region is formed between the drain region and the source region, such that when a bias potential is applied between the gate region and the source region, carriers flow to the drain region from the source region via the channel region. A source electrode is provided on the semiconductor layer. A source contact region is provided between the source electrode and the source region to establish electrical connection therebetween. The source contact region is segmented into a plurality of smaller regions or sections whose total area is smaller than the area of the corresponding portion of the source region, for improving the current gain, and for preventing or significantly reducing local current concentration.

Static induction type semiconductor device with multiple source contact

A static induction transistor has a gate region formed with a protrusion extending toward a drain region. The protrusion is located toward one side of the gate region such that a shallower gate region lies between the protrusion and the nearest source region. When a reverse voltage higher than the withstand voltage is applied between the gate and drain, avalanche breakdown occurs only in a region immediately below the protrusion, and no hot carriers are allowed to flow into a source region. Deterioration of the voltage-withstanding property and destruction of the device is thereby prevented. Another embodiment has a semiconductor region of a first conductivity type formed in a peripheral portion of a semiconductor layer of the first conductivity type in which a plurality of gate regions are disposed and adjacent a first major surface thereof. The distance between the semiconductor region and the nearest gate region is less than the distance between gate and drain regions such that the withstand voltage between the semiconductor region and the nearest gate region is less than that between the gate region and drain region. When a reverse bias voltage higher than a withstand voltage is applied between the gate and drain, the avalanche breakdown occurs only between the semiconductor region and the gate region nearest thereto.

Static induction transistor

A transistor provided with a current detecting function does not need any external resistance to detect current but uses a part of the electrode wiring through which main current flows as a resistance to prevent power loss. It detects the magnitude of main current on the basis of voltage drop caused by the resistance. Further, a stable sense voltage can be obtained without being affected by temperature change and sense voltages caused at the both ends of a sense resistance can be maintained constant with temperature change. Sense voltages can accurately correspond to the magnitude of main current flowing through a main transistor to enable excess current to be detected accurately.

Transistor provided with a current detecting function

A static induction type semiconductor device is used as a power transistor. It is of the surface gate type and is used for providing a high current density. The static induction type semiconductor device provides a plurality of small source regions surrounded by a gate region. According to this structure, the channel region beneath the source region becomes small, thereby increasing the stored carrier density and enabling a large main current to flow when using a small gate current, thereby achieving a high current amplification ratio. Further, when it flows the main current is distributed to the source regions, thus preventing increase in on-voltage.

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Aichi, Japan

Shinobu Aoki