Electronic control device
View Patent ↗In a step-up circuit, which is an electronic control device, changes in current caused by a current rise when stepping up is started and a current drop when stepping up is stopped generate magnetic induction noise due to fluctuations in the electromagnetic induction voltage in signal lines around the step-up circuit. The present invention is a step-up circuit for stepping up by current control, wherein the step-up circuit is provided with a plurality of target current values for retaining a step-up current so that the current is raised in a stepwise manner when stepping up is started and dropped in a stepwise manner when stepping up is stopped. The present invention reduces electromagnetic induction noise generated by the changes in current when stepping up is started and when stepping up is stopped.
1. An electronic control device comprising:
a step-up switching element, a coil, and a diode configured to generate a step-up voltage; and
a capacitor mounted to store the step-up voltage, wherein
current values at a time of a current rise when stepping up is started are controlled in a stepwise manner such that a plurality of current values are used as a current is increased in the stepwise manner during the current rise, and the current values at a time of a current drop when stepping up is stopped are controlled in the stepwise manner such that the plurality of current values are used as the current is decreased in the stepwise manner during the current drop.
2. The electronic control device according to claim 1 , wherein
the current values are controlled in the stepwise manner by varying ON/OFF Duty of the step-up switching element and a frequency.
3. The electronic control device according to claim 1 , further comprising:
a current monitor circuit configured to perform current control to step up, wherein
a plurality of target current values to control stepping up is provided.
4. The electronic control device according to claim 3 , wherein
each of the plurality of target current values is provided with upper and lower limit thresholds of the current, and
when the current exceeds a respective target current value of the plurality of target current values, the step-up switching element retains and controls the current so that the current does not exceed the upper and lower limit thresholds of the respective target current value immediately.
5. The electronic control device according to claim 3 , wherein
each of the plurality of target current values is provided with upper and lower limit thresholds of the current,
when the current exceeds a respective target current value of the plurality of target current values, the step-up switching element retains and controls the current so that the current does not exceed the upper and lower limit thresholds of the respective target current value immediately, and
a current profile at the time of the current rise in a stepwise manner is varied based on a retaining time to retain and control the current.
6. The electronic control device according to claim 3 , wherein
each of the plurality of target current values is provided with upper and lower limit thresholds of the current,
when the current exceeds a respective target current value of the plurality of target current values, the step-up switching element retains and controls the current so that the current does not exceed the upper and lower limit thresholds of the respective target current value immediately, and
a current profile at the time of the current drop in a stepwise manner is varied based on a retaining time to retain and control the current.