Toyota Jidosha Kabushiki Kaisha

Yoshitaka Ojima

Mitsugu Makita

Shouji Abo

Hironobu Kusafuka

Yoshinobu Kume

Yusuke Moritani

A PWM signal generating circuit according to the invention includes a digital PWM signal generating circuit that generates a digital PWM signal having a resolution of 2n based on a clock signal CLK and n-bits (n&#x2267;1) of digital information; a triangular wave generator that generates a triangular wave (e.g. ramp wave) synchronized with the clock signal CLK; and a comparator that compares the triangular wave with a threshold value. The PWM signal generating circuit increases the resolution of the digital PWM signal based on an output from the comparator.

PWM signal generating circuit

A voltage raising device that provisionally maintains an operation and function when there is an abnormality provided. If a battery voltage drops when an engine is restarted after an idle stop, the voltage raising device raises the output voltage to a target voltage by using a voltage detecting circuit and a current detecting circuit. If an overcurrent determining circuit detects overcurrent, a switching control circuit reduces the target voltage to perform a control. If overvoltage is output, for example, due to an increased target voltage caused by an internal setting deviation resulting from a failure, an overvoltage detecting circuit outputs a prohibition signal ENV to stop the switching operation. However, as long as the output voltage is not overvoltage, the voltage raising operation is allowed. Therefore, the possibility that the engine can be started at least once without a problem is increased.

Voltage generator device, motor vehicle, control method for the voltage generator device, control method for the motor vehicle, and computer-readable recording medium storing program for causing computer to execute the control method

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Toyota, Japan

Yoshitaka Ojima