Hitachi, Ltd.

Yasuo Nagai

Isao Shimizu

Kazuji Yamada

Ryoichi Kobayashi

Kanji Kawakami

Kenji Kaneko

Takeaki Okabe

Masatoshi Kimura

Kazuhiko Kawai

Koozoo Sakamoto

A semiconductor integrated circuit device includes a high voltage circuit and a high-speed signal processing circuit on the same chip. The high-speed signal processing circuit is made to have a stacked construction thereby to reduce the power consumption. It is also surrounded by ground potential lines so that it may be prevented from being adversely affected by a high voltage used in the high voltage circuit. Each of the high voltage elements composing the high voltage circuit has its principal surface formed at its base and collector regions with guard ring layers of the same conduction types as the respective ones of the high voltage elements. The guard ring layers extend over the elements and the semiconductor body and have lower impurity concentrations than the respective ones of the elements.

Semiconductor integrated circuit device

A detecting circuit for detecting electric abnormality of a pair of feeders is provided with resistors R.sub.A and R.sub.B converting the abnormality of the feeders into a change in voltage, transistors (Q.sub.8, Q.sub.9 and Q.sub.10) supplying or interrupting a current I.sub.B in response to presence or absence of an abnormal state, transistors (Q.sub.5, Q.sub.6 and Q.sub.17) drawing in or blocking a current I.sub.A in response to the abnormal state, a current subtraction element (I) conducting a subtraction of the currents I.sub.B and I.sub.A on an absolute value basis, a current addition element (II) conducting an addition of the currents I.sub.A and I.sub.B, a current addition element (III) adding the output currents of the current subtraction element (I) and current addition element (II), and a voltage comparator (6) subjecting the output current of the current addition element (III) to current-voltage conversion and comparing a voltage thus obtained with a reference voltage so as to obtain an abnormality detection signal, which is used to interrupt the feeding of electricity to the paired feeders when an abnormality is detected.

Circuit for detecting abnormality in feeder

A current source device controls a rate of change of current flowing through a load so that the change rate of the current is equal to a change rate of a fluctuating supply voltage. A first transistor is fed with the supply voltage via a first resistor connected to its collector and a second resistor connected to its emitter. A second transistor has a base connected to a base of the first transistor, an emitter connected to a third resistor and a collector connected to a load. A current to the load is fed from the supply voltage via the load, the collector and emitter of the second transistor and the third resistor. The collector and base of the first transistor are respectively connected to a base and an emitter of a third transistor having a collector fed with the supply voltage. The ratio between a voltage drop caused across the second resistor by a reference current flowing through the first resistor, the collector and emitter of the first transistor and the second resistor, and a voltage drop caused across the third resistor by an emitter current of the second transistor, which is substantially equal to a collector current of the second transistor flowing through the load, is set to a predetermined value. The emitter area of the second transistor is enlarged beyond that of the first transistor to obtain a sufficiently large output current.

Constant current source device having a ratio metricity between supply

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Maebashi, Japan

Yasuo Nagai