Denso Corporation

Susumu Ueda

Tadatoshi Asada

Hirokazu Toyoda

Hideto Okahara

Shinichi Konda

Masaki Mori

A temperature detection circuit includes a bandgap reference voltage generation circuit, a detection output circuit, and an output conversion circuit. The bandgap reference voltage generation circuit generates a first reference voltage and causes a bias current to flow through a current path to produce a thermal voltage. The current path has a first resistor. The detection output circuit has a second resistor and causes a mirror current of the bias current to flow through the second resistor. The output conversion circuit uses a second reference voltage to convert a voltage drop across the second resistor to a predetermined output form to detect a temperature. The first and second resistors are substantially identical in temperature dependence. The second reference voltage is generated from the first reference voltage.

Temperature detection circuit

A noise free transceiver circuit includes a communication line, a power source line, a ground line, an output transistor having output terminals connected between the communication line and the ground line for outputting a communication signal to the communication line, a first circuit for applying a trapezoidal signal to the input terminal of the output transistor to turn on in synchronism with a transmission signal and a second circuit for turning off the output transistor when the level of the transmission signal is high. The output transistor is turned off when the communication signal is outputted. Therefore, noises of the power line are shut out of the output transistor.

Noise free transceiver circuit

An overcurrent protecting device for protecting a semiconductor element from an overcurrent includes: the semiconductor element; a shunt resistor for detecting the overcurrent when the electric current in the semiconductor element exceeds a threshold value; a reference resistor for setting the threshold value; a constant electric current circuit for supplying a constant electric current to the reference resistor; and a comparator for comparing a terminal voltage of the shunt resistor and a terminal voltage of the reference resistor. The shunt resistor is made of a same kind of resistor as the reference resistor.

Overcurrent protection device for semiconductor element

A signal detecting device detects, as analog voltage signals, a current flowing through an exciting coil of an electric power generator, a source voltage and a temperature of a regulator that change as a current is fed to the exciting coil by an FET. These analog voltage signals are subjected to A/D conversion by a single A/D converter circuit. The detected current is subjected to A/D conversion in a period during which the FET is ON, while the detected source voltage and the detected temperature are subjected to A/D conversion in a period during which the FET is OFF.

Signal detecting device and method for inductive load

A motor control system designed to monitor a failure in a multi-phase dc motor is provided. The motor control system includes an inverter which controls an operation of the motor, a failure detecting circuit which monitors the voltage appearing at one of terminals of armature windings of the motor every active time when a PWM signal is at an active level to turn on switching elements of the inverter and determines occurrence of the failure based on the monitored voltage, and a switching operation prohibiting circuit which prohibits one of the switching elements connected to the one of the terminals of the windings of the motor from being turned on, thereby avoiding additional damages of the motor control system.

Growing community of inventors

Okazaki, Japan

Susumu Ueda