Abstract: An abnormal state latch unit comprises: an detection circuit that masks an abnormality position signal; a timer circuit that starts motion when the abnormality position signal indicates the occurrence of an abnormality based on the abnormality position signal, and completes the motion and outputs a reset signal after passage of a predetermined period; and a latch circuit that latches the abnormality position signal output from the detection circuit when the reset signal is output. The detection circuit masks the abnormality position signal when the latch circuit makes latching motion to disable an output from the detection circuit. The timer circuit masks an input to the timer circuit when the latch circuit makes the latching motion to maintain a state indicating completion of the motion. Abnormality voltage signals generated by an signal generation circuit are wired-OR connected and supplied through a single signal line to a monitor circuit.

Abstract: An abnormal state latch unit comprises: an detection circuit that masks an abnormality position signal; a timer circuit that starts motion when the abnormality position signal indicates the occurrence of an abnormality based on the abnormality position signal, and completes the motion and outputs a reset signal after passage of a predetermined period; and a latch circuit that latches the abnormality position signal output from the detection circuit when the reset signal is output. The detection circuit masks the abnormality position signal when the latch circuit makes latching motion to disable an output from the detection circuit. The timer circuit masks an input to the timer circuit when the latch circuit makes the latching motion to maintain a state indicating completion of the motion. Abnormality voltage signals generated by an signal generation circuit are wired-OR connected and supplied through a single signal line to a monitor circuit.

Abstract: In a digitally controlled power source, a setting value of an output voltage therefrom is set in advance in the vicinity of an upper limit within a tolerable range of fluctuation. Even if a voltage drop is caused by starting currents that flow upon initial rise of DC-DC converters in a subsequent stage, such setting makes it possible to confine values of the output voltage within the tolerable range of fluctuation because the setting value of the output voltage is set in advance at a relatively high value. Accordingly, the starting currents in the DC-DC converters can be increased without restriction so that rise time for the power source can be shortened.

Abstract: In a digitally controlled power source, a setting value of an output voltage therefrom is set in advance in the vicinity of an upper limit within a tolerable range of fluctuation. Even if a voltage drop is caused by starting currents that flow upon initial rise of DC-DC converters in a subsequent stage, such setting makes it possible to confine values of the output voltage within the tolerable range of fluctuation because the setting value of the output voltage is set in advance at a relatively high value. Accordingly, the starting currents in the DC-DC converters can be increased without restriction so that rise time for the power source can be shortened.

Abstract: In a DC/DC converter, each channel operates under digital control using nonlinear control. The time interval between the time of turning ON of the switching element 1 and the time of turning ON of each of other switching elements j (j=2, 3, . . . , N) is measured. If the measured interval is within a specified range, operation is continued without changing the ON time of the switching element j used last time. Meanwhile, if the measured interval is out of the range, the ON time of the switching element j is increased or decreased within a predetermined range to be shifted from a basic frequency. Thus, the interval between the time of turning ON of the switching element 1 and the time of turning ON of the switching element j is brought back to the specified range.

Abstract: In a DC/DC converter, each channel operates under digital control using nonlinear control. The time interval between the time of turning ON of the switching element 1 and the time of turning ON of each of other switching elements j (j=2, 3, . . . , N) is measured. If the measured interval is within a specified range, operation is continued without changing the ON time of the switching element j used last time. Meanwhile, if the measured interval is out of the range, the ON time of the switching element j is increased or decreased within a predetermined range to be shifted from a basic frequency. Thus, the interval between the time of turning ON of the switching element 1 and the time of turning ON of the switching element j is brought back to the specified range.