摘要:
There is disclosed an A-D converter testing circuit wherein exclusive-OR gates (13a, 13b) provide the exclusive-OR of the high-order bits (D.sub.1a, D.sub.1b) of the outputs of A-D converters (12a, 12b) and the exclusive-OR of the high-order bits (D.sub.1b, D.sub.1c) of the outputs of A-D converters (12b, 12c), respectively, and an OR gate (13c) provides the logical sum of the outputs of the both gates, which is "L" if all of the bits (D.sub.1a, D.sub.1b, D.sub.1c) are equal. A tri-state buffer (15a) receives the output of the OR gate (13c) at its control end and receives the bit (D.sub.1c) at its input. When all of the A-D converters are normal, all of the bits (D.sub.1a, D.sub.1b, D.sub.1c) are equal and are applied to the output of the tri-state buffer (15a). When one or some of the A-D converters are abnormal, the output of the tri-state buffer (15a) enters a high-impedance state. The A-D converter testing circuit, therefore, rapidly judges whether the A-D converters are defective or non-defective.
摘要:
The present invention is directed to improvement of a differential amplifier an its peripheral components employed in an A/D converter to enhance an accuracy of the A/D converter. The differential amplifier has an amplifying element comprised of a pair of differential transistors Q1 and Q2, emitter resistances 2a and 2b, and collector resistances 2c and 2d. The differential amplifier has transistors Q3 and Q4 constituting an emitter follower for applying an output amplified in the differential amplifying element to the outside. The differential amplifier includes transistors Q5 and Q6 having their respective base electrodes connected to input terminals 4a and 4b and serially connected to the transistors Q3 and Q4, and resistances 2e and 2f interposed between emitter electrodes of the transistors Q5 and Q6 so as to relieve any influence of variations in base-emitter voltages of the transistors Q3 and Q4. Effectively an output from the emitter follower can be improved and a gain of the differential amplifier and linearity can be also improved.
摘要:
In order to improve linearlity of analog current outputs with respect to input digital codes in a D-A converter formed by a matrix array of unit current sources, respective current source cells forming the matrix are connected by analog ground wires (101 to 105 ) along respective rows. Analog ground wires (301, 302 ) connect left sides of the analog ground wires (102, 104) and right sides of the analog ground wires (101, 103, 105) to pads (41, 42 ) respectively, to ground the same. Thus, large-small relations of current distributions are reversed in respective rows, whereby influences by the current distributions are cancelled.
摘要:
An analog voltage subtracting circuit for calculating a difference between an analog input voltage and a voltage drop caused by a load includes an analog voltage generator 7 for generating an analog voltage, a load 3 having one end connected to an output of the analog voltage generator 7 and the other end connected to an output terminal 2, and a D/A converter 6 applying a positive output current Iout for generating a desired voltage drop at said the other end 4 of the load 3 and for applying a complementary output current Iout complementary to the positive output current Iout to said one end of the load 3. By this structure, a constant current of Iout+Iout flows at said one end 4 of the load 3, and therefore linear output can be provided.
摘要:
A semiconductor integrated circuit device comprises a general purpose unit having a general purpose function and a specific unit for a specific use of the semiconductor integrated circuit device. In addition, the semiconductor integrated circuit device has structure in which a plurality of layers each having an integrated circuit formed therein are stacked in a three-dimensional manner. Specific unit layers are formed on the surface of the layer having the general purpose unit formed therein by different manufacturing processes.
摘要:
A Hall device a semiconductor region embedded in a substrate, the embedded region having opposite main and back surfaces and a pair of side surfaces parallel to and spaced apart from respective ones of the main, back and side surfaces of the substrate. A pair of current electrodes are formed of first highly doped regions embedded in the substrate respectively (i) between the main surfaces of the substrate and the semiconductor region and (ii) between the back surfaces of the substrate and semiconductor region so as to sandwich the semiconductor region between the main and back surfaces of the substrate. A pair of Hall voltage detecting electrodes are formed of second highly doped regions embedded in the substrate, respectively between side surfaces of the substrate and semiconductor region. The substrate can be made of SiO.sub.2 to increase electrical isolation between the electrodes.
摘要:
The inventive multilayer semiconductor integrated circuit has a columnar semiconductor region provided between adjacent two layers and a control electrode provided in the vicinity of the columnar semiconductor region. The transference of a signal between the adjacent two layers is carried out through the columnar semiconductor region the electric conductivity of which is controlled by a control signal applied to the control electrode. That is, the area corresponding to the columnar semiconductor region functions as an active element.
摘要:
A semiconductor device of the invention has a plurality of resistor elements formed on an element isolating oxide film in predetermined regions on a surface of a semiconductor substrate. Active regions are furnished close to the resistor elements. This allows the element isolating oxide film near the resistor elements to be divided into suitable strips, forestalling a concave formation at the center of the element isolating oxide film upon polishing of the film by CMP and thereby enhancing dimensional accuracy of the resistor elements upon fabrication.
摘要:
An oscillator circuit is formed of a differential LC resonant circuit formed of an L load differential circuit including inductance-variable portions and a capacitive element, and a positive feedback circuit formed of N-channel MOS transistors. The inductance-variable portion is configured to vary the inductance by selecting a plurality of switch circuits arranged between a plurality of arbitrary positions on a spiral interconnection layer and the input/output terminal, and thereby can control an oscillation frequency. The inductance-variable portions form an inductor pair when the switch circuit among the switch circuits coupled between the first input/output terminals is turned on together with the switch circuit.
摘要:
A semiconductor device of the invention has a plurality of resistor elements formed on an element isolating oxide film in predetermined regions on a surface of a semiconductor substrate. Active regions are furnished close to the resistor elements. This allows the element isolating oxide film near the resistor elements to be divided into suitable strips, forestalling a concave formation at the center of the element isolating oxide film upon polishing of the film by CMP and thereby enhancing dimensional accuracy of the resistor elements upon fabrication.