Kabushiki Kaisha Tokai Rika Denki Seisakusho

Satoki Uruno

Junichi Matsubara

Kengo Shima

Daisuke Aoki

Yuichiro Mori

Natsuki Arakawa

Yusuke Kamiya

A semiconductor integrated circuit includes a constant-voltage circuit that outputs a constant voltage and a constant-current circuit. The constant-current circuit includes a first transistor. A voltage input as an input voltage to a first gate electrode of the first transistor is equal to the node voltage at an intermediate node in a connection path between the output of the constant-voltage circuit and an external resistor. A source region of the first transistor is connected to a fixed power supply, and a drain region of the first transistor is connected to the external power supply via a load. In the first transistor, a constant current can be made to flow between the source region and the drain region based on the input voltage. A constant-current drive system in which the semiconductor integrated circuit and the external resistor have been mounted on a circuit board is also constructed.

Circuit and constant-current drive system having adjustable constant current output

A signal processing device includes an input terminal configured to be input with an input signal that is active high or an input signal that is active low, a switching terminal connectable to a power supply or ground, a selection circuit configured to select and output the input signal that is active high in a case that the switching terminal is connected to the power supply and select and output the input signal that is active low in a case that the switching terminal is connected to the ground.

Signal processing device

An indicator drive circuit includes a current mirror circuit including a first transistor located at a control side and a second transistor located at a controlled side, a current through the current mirror circuit being switched by an external control signal, a current source adapted to feed a control current to the first transistor of the current mirror circuit, and a switching element adapted to be driven by a current through the second transistor of the current mirror circuit and to switch on or off an indicator light source. The current source includes two transistors cascode-connected.

Growing community of inventors

Aichi, Japan

Satoki Uruno