Abstract: When a transmission signal is detected as having been changed from a high level to a low level, two transmission lines are connected for only a predetermined time through a diode by a first transistor and a second transistor. The diode is arranged such that its forward direction is from a high-side transmission line to a low-side transmission line. The diode turns on, when a potential of the high-side transmission line becomes higher than that of the low-side transmission line by ringing and a potential difference therebetween exceeds a forward drop voltage of the diode. As a result, a peak wave level of a positive side in the ringing is limited to the forward drop voltage of the diode.

Abstract: A ringing suppression circuit for a communication circuit that performs communication through a transmission line includes a high side switch connected between a high potential reference point and a high side line of the transmission line, a low side switch connected between a low potential reference point and a low side line of the transmission line, and a ringing suppression section. The ringing suppression section turns on the high side switch based on a difference between a potential of the high side line and a potential applied to a control terminal of the high side switch. The ringing suppression section turns on the low side switch based on a difference between a potential of the low side line and potential applied to a control terminal of the low side switch.

Abstract: In a transmission device for differential communication, a first cathode-side element part is coupled between a first communication line and a cathode-side power supply line, a second cathode-side element part is coupled between a second communication line and the cathode-side power supply line, a first anode-side element part is coupled between the first communication line and an anode-side power supply line, and a second anode-side element part is coupled between the second communication line and the anode-side power supply line. A driving portion drives the element parts based on transmission data input from an outside. A target potential generating portion generates target potentials of the element parts based on potentials of the first communication line and the second communication line.

Abstract: A transmission apparatus for differential communication includes a driver bridge circuit and a pair of noise protection circuits. The driver bridge circuit includes four output devices that are independently connected between each of a pair of transmission lines and a power line or a ground line. Each noise protection circuit is provided to a corresponding transmission lines. Each noise protection circuit includes a ground potential detector and an impedance controller. The ground potential detector detects a potential of the corresponding transmission line with respect to the ground line. The impedance controller causes an impedance of the corresponding transmission line with respect to the ground line to become equal to an impedance of the other transmission line with respect to the ground line, when the detected potential becomes outside a predetermined potential range.

Abstract: A circuit system includes: a master node; and a slave portion including a plurality of non-grounded slave nodes, each of which couples with the master node through a pair of communication lines. The master node and the slave portion provide a differential transmission system for differentially transmitting a signal among the master node and the slave nodes. The slave portion has a predetermined impedance. The differential transmission system has a good signal condition and a sufficient low common mode noise.

Abstract: A receiving device includes a receiving circuit and an impedance control circuit. The receiving circuit receives a signal transmitted through a communication line. The impedance control circuit is coupled with the receiving circuit and has a detecting part. The detecting part detects a physical value of the signal and the physical value includes at least one of a voltage, an electric current, and an electric power. The impedance control circuit changes an input impedance based on the detected value so that a ringing of the signal is reduced.

Abstract: A signal receiver includes: a receiving circuit that receives a differential signal via a transmission line, which includes a pair of signal wires for transmitting the differential signal; and an impedance control circuit that controls an input impedance so as to reduce a common mode noise. The impedance control circuit includes a detection element for detecting at least one of a voltage, a current and an electric power of the common mode noise. The impedance control circuit controls the input impedance in accordance with change of the at least one of the voltages the current and the electric power of the common mode noise.

Abstract: A circuit system includes: a master node; and a slave portion including a plurality of non-grounded slave nodes, each of which couples with the master node through a pair of communication lines. The master node and the slave portion provide a differential transmission system for differentially transmitting a signal among the master node and the slave nodes. The slave portion has a predetermined impedance. The differential transmission system has a good signal condition and a sufficient low common mode noise.

Abstract: A sample, a reagent, etc. in a reaction container 132 is agitated with an ultrasonic wave generated from a piezoelectric transducer (141, 142). A power supply unit (144) applies, to the piezoelectric transducer, a voltage having been subjected to frequency modulation at frequencies over an optional frequency range. An analyzing section (130) measures a reaction product produced as an analysis target from the reagent, etc. and the sample under agitation, and then analyzes components of the sample. With such a construction, adjustment work needed in an agitating section can be simplified, and satisfactory analyzed results can be obtained regardless of differences in frequency characteristics of ultrasonic wave generators used for ultrasonic agitation.