Abstract: A modulator includes an integrator, an input chopping switch, and output chopping switch, and a control circuit. The integrator has a differential amplifier, a first switch and a series circuit. The first switch is connected between input and output terminals of the differential amplifier. The series circuit is connected between the input and output terminals of the differential amplifier. The series circuit has a second switch, an input capacitance chopping switch, an integration capacitor and an output capacitance chopping switch. The control circuit controls the input chopping switch and the output chopping switch to execute chopping being at a chopping frequency identical to the input capacitance chopping switch and the output capacitance chopping switch. The chopping frequency of the input and output capacitance chopping switches is lower than a switching frequency of the first switch.

Abstract: A reference voltage generation circuit includes a Zener diode and a current generation circuit connected to the Zener diode in parallel. The current generation circuit includes a resistance voltage divider circuit, a transistor circuit and a voltage control circuit. The resistance voltage divider circuit has a branch portion for branching the current into two paths, and outputs a reference voltage acquired by voltage division through a resistive element. The transistor circuit includes two NPN transistors and a series resistance circuit in which resistive elements are connected in series. The two NPN transistors respectively having collectors, bases and emitters. The collectors are respectively connected to the two paths. The bases have a common connection. The series resistance circuit is connected between a ground and one of the emitters. The voltage control circuit equalizes respective collector potentials of the two NPN transistors.

Abstract: An amplifier circuit includes: an amplifier; a first switched resistor unit configured by connecting in series a first resistance element having one or more resistors and a first switch, and having one end connected to an input terminal of the amplifier; a second resistance element unit connected between an other end of the first switched resistor unit and an output terminal of the amplifier and including one or more resistors; a second switch connected between a common connection point of the first switched resistor unit and the second resistance element unit and a reset potential point; and a control circuit for exclusively turning on and off the first switch and the second switch, respectively.

Abstract: A current sensor includes a current detection unit, a relay, a relay control unit, and a resistance value correction circuit. The current detection unit detects a detection target current based on a terminal voltage of a shunt resistor located in series with a path through which the detection target current flows and a detection resistance value for current detection corresponding to a resistance value of the shunt resistor. The relay is located in series with the path through which the detection target current flows. The relay control unit controls the relay to be turned on or off. The resistance value correction circuit calculates the resistance value of the shunt resistor as a calculated resistance value and corrects the detection resistance value based on the calculated resistance value.

Abstract: A current sensor for a detection target current using a shunt resistor includes: a resistance value correction circuit having a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a voltage detection unit that detects terminal voltages of the shunt resistor and the correction resistor; and a correction unit that calculates a resistance value of the shunt resistor and corrects the resistance value for detection; and a power supply circuit having a first power supply generation unit that generates a first power supply of the signal application unit from an input power supply of an outside; and a second power supply generation unit that generates a second power supply of the voltage detection unit.

Abstract: In a communication system, a control unit and driver units are connected in a daisy chain; each unit includes a corresponding insulated communication circuit, respectively. The control unit measures a communication delay time between the control unit and each driver unit from a response time to transmission of a pulse signal performed to each driver unit during a measurement period. Then, based on each communication delay time, the control unit transmits a shift time to each driver unit for equalizing the timing of signals output by the driver units. When each driver unit receives, from the control unit, an instruction instructing each driver unit to output a signal, each driver unit outputs the signal when the shift time has elapsed.

Abstract: An assembled battery monitoring device in the present disclosure includes: an excitation signal processor generates a excitation signal by processing an in-phase signal of an orthogonal reference signal generated by a signal generator; a current exciter generates an excitation current based on the excitation signal according to voltage signals, and energizes a battery cell; and an impedance measurer measures an AC impedance of the battery cell based on the excitation current measured by the current measurer and a voltage of the battery cell measured by the voltage measurer.

Abstract: A delta-sigma modulator includes a capacitively-coupled amplifier, a first integrator, a second integrator, a quantizer, a first switch, a second switch, and a control circuit. The first switch is connected between an input of the capacitively-coupled amplifier and a sampling capacitor of the capacitively-coupled amplifier to execute a chopping operation. The second switch is connected between an output of the capacitively-coupled amplifier and an input of the first integrator to execute a chopping operation. The control circuit executes modulation through the first switch at the input of the capacitively-coupled amplifier, executes demodulation through the second switch at the output of the capacitively-coupled amplifier, and imports an output signal of the capacitively-coupled amplifier into the first integrator after the demodulation.

Abstract: A current sensor for detecting a current based on a terminal voltage and a resistance value of a shunt resistor, includes: a resistance value correction circuit having: correction resistors; a signal application unit; a voltage detection unit that detects terminal voltages of the shunt resistor and a part of the correction resistors in a first period, and terminal voltages of all of the correction resistors in a second period; and a correction unit that corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor. Resistance values and resistance accuracies of the correction resistors are higher as the plurality of correction resistors are disposed farther from the shunt resistor.

Abstract: A differential communication circuit is connected to a communication line formed of a positive communication line and a negative communication line for differential communication. The differential communication circuit includes: a series circuit that includes a resistor element and a connection switch. The resistor element is connected between the positive and negative communication lines when the connection switch is turned on. The circuit also includes a transmission unit that is configured to output a differential signal to the communication line and a controller that is configured to change impedance of the communication line by turning on the connection switch in a period during which the transmission unit does not output the differential signal.

Abstract: A current sensor of a detection target current using a shunt resistor includes: a resistance value correction circuit having: a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a first voltage detection unit that detects the terminal voltage of the shunt resistor; a second voltage detection unit that detects a terminal voltage of the correction resistor; and a correction unit that calculates the resistance value of the shunt resistor based on a first voltage detection value by the first voltage detection unit and a second voltage detection value by the second voltage detection unit, and corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor.

Abstract: An insulated communication system includes a communication controller that sets communication data to a communication symbol through a numeral system and executes insulated communication through an insulator by adopting the communication symbol. The numeral system includes multiple states having a positive state, a negative state and a zero state. The positive state is represented by at least one positive integer, and the negative state is represented by at least one negative integer. The zero state is represented by zero being a level without generating current consumption. An absolute value of the at least one positive integer and an absolute value of the at least one negative integer are identical to each other. The communication controller sets an initial section of the communication data in the communication symbol to the positive state or the negative state, and sets a following section of the communication data to one of the multiple states.

Abstract: A battery monitoring system that monitors states of a plurality of batteries. The battery monitoring system includes a battery monitoring ECU and a plurality of battery monitoring devices. The battery monitoring ECU and the plurality of battery monitoring devices are connected to each other in any connection form of ring connection, daisy chain connection, or multi-drop connection.

Abstract: A battery monitor system includes: a reference signal generation unit; an excitation signal generation unit; a current generation unit for an excitation current; a current measurement unit for the excitation current; a voltage measurement unit for a voltage of each battery cell; an impedance measurement unit for an impedance of each battery cell; a noise measurement unit for a noise voltage; and a control unit. The control unit selects one or more battery cells not a measurement target, and the noise measurement unit measures the noise voltage near a measurement frequency equal to a frequency of an orthogonal reference signal while operating the voltage measurement unit without operating the current generation unit.

Abstract: A battery monitoring system includes a battery monitoring ECU and battery monitoring devices which are sequentially connected in a connection configuration. The battery monitoring ECU includes a clock generator that generates a first clock signal. Each battery monitoring device includes a second clock generator that generates a second clock signal, a controller that causes a frequency correction block to correct a frequency of the second clock signal in line with the first clock signal and causes the battery monitor to monitor a battery cell using the second clock signal that has been corrected, and a switch that, according to an instruction of the battery monitoring ECU, switches a circuit configuration to a state in which a signal received from a preceding device is transmitted to a succeeding device in the connection configuration.

Abstract: A differential transmission circuit for a communication device performs bidirectional communication via a differential transmission line. The differential transmission circuit include: output transistors that are turned on and off according to a drive signal during a transmission period; a signal generation unit that generates and outputs the drive signal; short-circuit transistors connected between gates and drains of the output transistors; and a cut off unit that cuts off a supply path of the drive signal between the signal generation unit and the gates of the output transistors. The cut off unit cuts off the supply path of the drive signal during a reception period in which a reception operation is performed by the communication device.

Abstract: A current sensor for a detection target current using a shunt resistor includes: a resistance value correction circuit having a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a voltage detection unit that detects terminal voltages of the shunt resistor and the correction resistor; and a correction unit that calculates a resistance value of the shunt resistor and corrects the resistance value for detection; and a power supply circuit having a first power supply generation unit that generates a first power supply of the signal application unit from an input power supply of an outside; and a second power supply generation unit that generates a second power supply of the voltage detection unit.

Abstract: A current sensor for detecting a current based on a terminal voltage and a resistance value of a shunt resistor, includes: a resistance value correction circuit having: correction resistors; a signal application unit; a voltage detection unit that detects terminal voltages of the shunt resistor and a part of the correction resistors in a first period, and terminal voltages of all of the correction resistors in a second period; and a correction unit that corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor. Resistance values and resistance accuracies of the correction resistors are higher as the plurality of correction resistors are disposed farther from the shunt resistor.

Abstract: A current sensor of a detection target current using a shunt resistor includes: a resistance value correction circuit having: a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a first voltage detection unit that detects the terminal voltage of the shunt resistor; a second voltage detection unit that detects a terminal voltage of the correction resistor; and a correction unit that calculates the resistance value of the shunt resistor based on a first voltage detection value by the first voltage detection unit and a second voltage detection value by the second voltage detection unit, and corrects the resistance value for current detection based on a calculated resistance value of the shunt resistor.

Abstract: A differential communication circuit is connected to a communication line formed of a positive communication line and a negative communication line for differential communication. The differential communication circuit includes: a series circuit that includes a resistor element and a connection switch. The resistor element is connected between the positive and negative communication lines when the connection switch is turned on. The circuit also includes a transmission unit that is configured to output a differential signal to the communication line and a controller that is configured to change impedance of the communication line by turning on the connection switch in a period during which the transmission unit does not output the differential signal.