Rohm Co., Ltd.

Akio Sasabe

Daiki Yanagishima

Masato Nishinouchi

Takeshi Kikuchi

Motohiro Ando

Toshiyuki Ishikawa

Makoto Ikenaga

Hirotaka Takihara

Tsuyoshi Fukura

A signal transmission device that transmits a driving signal for a power transistor from a primary circuit system to a secondary circuit system while isolating between the primary and secondary circuit systems includes: a first fault detection circuit configured to detect a fault in the primary circuit system; a second fault detection circuit configured to detect a fault in the secondary circuit system; a first signal transmission path configured to transmit the result of detection by the second fault detection circuit from the secondary circuit system to the primary circuit system while isolating between the primary and secondary circuit systems; and a self-test circuit configured to perform a self-test on each of the first fault detection circuit, the second fault detection circuit, and the first signal transmission path.

Signal transmission device, electronic device and vehicle

A signal transmission device transmits a driving signal for a gate-driving transistor between a primary circuit system and a secondary circuit system while isolating between the primary and secondary circuit systems. The signal transmission device includes: a first external terminal configured such that the ground terminal of the secondary circuit system is connected to it; a second external terminal configured such that the terminal voltage at it varies according to whether the first external terminal is in an open state; and an open detection circuit configured to monitor the terminal voltage at the second external terminal to perform open detection for the first external terminal.

Signal transmission device, electronic device, and vehicle

A signal transmission deviceincludes an isolated signal transmission circuitconfigured to transmit a pulse signal from a primary circuit systemvia a first isolating element ISOto a secondary circuit system, and an isolated power supply control circuitwhich serves as a controlling agent of an isolation-type power supply that generates a second supply voltage Vccfor the secondary circuit systemfrom a first supply voltage Vccfor the primary circuit systemand which transmits an output feedback signal of the isolation-type power supply from the secondary circuit systemvia a second isolating element ISOto the primary circuit system

Signal transmission device, electronic appliance, and vehicle

A pulse receiving circuit constituting a signal transmission device includes a first pulse detector that receives a differential input between a first reception pulse signal, i.e. an internal signal at a secondary winding of a first transformer and a second reception pulse signal, i.e. an internal signal at a secondary winding of a second transformer; a second pulse detector that receives the differential input between the first reception pulse signal and the second reception pulse signal with input polarity reversed to that of the first pulse detector; and a logic unit that generates a reception pulse signal based on output signals of the first and second pulse detectors, respectively.

Pulse receiving circuit and signal transmission device

A signal transmission device includes a capacitor having a first capacitor element and a second capacitor element connected in parallel such that electrodes of different polarities are connected together between them, and transmits an analog signal in a form converted into a pulse signal by use of a triangular-wave signal generated through charging and discharging of the capacitor.

A mirror clamp circuit includes a comparator having a first input terminal connectable to a first control terminal of a transistor having the first control terminal connected to the other terminal of a resistor of which one terminal is fed with an output voltage and a first terminal fed with a reference potential and a second input terminal fed with a reference voltage, a transistor switch having a second control terminal fed with a control terminal voltage based on a comparison signal output from the comparator and inserted between the first control terminal and the reference potential, an OR circuit fed with a signal based on the control terminal voltage and the output voltage, and a current feeder configured to change the amount of current fed to the comparator based on the output of the OR circuit.

Mirror clamp circuit

The load drive device of the present invention comprises a load drive unit for switching on/off output current that flows to an inductive load; and an overcurrent protection circuit for detecting whether the output current is in an overcurrent state, wherein the load drive unit has an output transistor connected to one end of the inductive load; and a pre-driver for generating a control signal of the output transistor in accordance with an input signal, and the pre-driver has a first drive unit for switching on/off the output transistor during normal operation; and a second drive unit for switching off the output transistor more slowly than the first drive unit during overcurrent protection operation.

Load drive device

A signal-transferring device having a first circuit and a second circuit that operate on different ground references, and a third circuit for transferring signals while providing insulation between the first circuit and the second circuit. The second circuit switches a logic level of an output signal in accordance with the logic level of an input signal notified by the first circuit, and notifies the first circuit about the logic level of the output signal. The first circuit notifies the second circuit about the logic level of the input signal not only when the logic level of the input signal has been switched, but also when the logic level of the output signal notified by the second circuit does not match the logic level of the input signal.

Growing community of inventors

Kyoto, Japan

Akio Sasabe