Abstract: An M-channel (M is an integer of at least two) synchronous rectification type step-down DC/DC converter is provided. A controller in the converter (i) calculates a load current on a basis of currents flowing through M inductors, (ii) dynamically changes the number K of driving phases (K is an integer of up to M) on the basis of the calculated load current, (iii) generates a pulse signal adjusted in duty ratio such that an output voltage of an output line coincides with a predetermined reference voltage, (iv) selects K drivers among M drivers, and distributes the pulse signal with a phase difference of (360/K) degrees to each of the selected K drivers, and (v) monotonically increases an amplitude control signal indicating the amplitude of a gate driving voltage with respect to the calculated load current in a range determined in advance for each number K of driving phases.

Abstract: The present disclosure is to provide a DC/DC converter capable of suppressing increase in the ripple amount of the output voltage in association with switching of the number of drive phases. N (N is an integer equal to or larger than 2) switching circuits each generate a switching voltage at the switching node according to an input pulse signal. A phase controller dynamically switches the number K (K is an integer equal to or smaller than N) of drive phases according to the state of a DC/DC converter at the time. A pulse modulator generates a pulse signal whose frequency changes according to the number K of drive phases. A distributor selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of (360/K) degrees.

Abstract: An M-channel (M is an integer of at least two) synchronous rectification type step-down DC/DC converter is provided. A controller in the converter (i) calculates a load current on a basis of currents flowing through M inductors, (ii) dynamically changes the number K of driving phases (K is an integer of up to M) on the basis of the calculated load current, (iii) generates a pulse signal adjusted in duty ratio such that an output voltage of an output line coincides with a predetermined reference voltage, (iv) selects K drivers among M drivers, and distributes the pulse signal with a phase difference of (360/K) degrees to each of the selected K drivers, and (vi) monotonically increases an amplitude control signal indicating the amplitude of a gate driving voltage with respect to the calculated load current in a range determined in advance for each number K of driving phases.

Abstract: Based upon a detection voltage VL that develops between ISEN+ and ISEN? terminals, a current detection circuit detects a coil current IL that flows through an inductor. A measurement circuit is connected to an inductor, and measures an inductance value L and a DC resistance value RDC of the inductor in a calibration operation before normal operation of a DC/DC converter. Based upon the inductance value L and the DC resistance value RDC thus measured, the current detection circuit detects the coil current IL using the detection voltage VL.

Abstract: The present disclosure is to provide a DC/DC converter capable of suppressing increase in the ripple amount of the output voltage in association with switching of the number of drive phases. N (N is an integer equal to or larger than 2) switching circuits each generate a switching voltage at the switching node according to an input pulse signal. A phase controller dynamically switches the number K (K is an integer equal to or smaller than N) of drive phases according to the state of a DC/DC converter at the time. A pulse modulator generates a pulse signal whose frequency changes according to the number K of drive phases. A distributor selects K switching circuits among the N switching circuits and distributes the pulse signal to each of the selected K switching circuits with a phase difference of (360/K) degrees.

Abstract: In a power supply apparatus for supplying a target power supply voltage to a microprocessor, a system controller sets the target power supply voltage to be supplied to the microprocessor based on a voltage configuration signal outputted from the microprocessor and outputs a voltage setting signal corresponding to the target power supply voltage. The regulator circuit generates the target power supply voltage set by the system controller based on the voltage setting signal outputted from the system controller and supplies the voltage to the microprocessor 10. The system controller acquires the conditions of the microprocessor, such as the operating time and temperature of the microprocessor and the amount of computation in the microprocessor, and reflects the acquired conditions on the setting of the power supply voltage.

Abstract: In a power supply apparatus for supplying a target power supply voltage to a microprocessor, a system controller sets the target power supply voltage to be supplied to the microprocessor based on a voltage configuration signal outputted from the microprocessor and outputs a voltage setting signal corresponding to the target power supply voltage. The regulator circuit generates the target power supply voltage set by the system controller based on the voltage setting signal outputted from the system controller and supplies the voltage to the microprocessor 10. The system controller acquires the conditions of the microprocessor, such as the operating time and temperature of the microprocessor and the amount of computation in the microprocessor, and reflects the acquired conditions on the setting of the power supply voltage.

Abstract: A power supply circuit produces a supply voltage to be supplied to a microprocessor which is an integrated circuit. A transmission line type noise filter includes a signal input terminal, a signal output terminal and two ground terminals corresponding respectively to the signal input terminal and the signal output terminal. The transmission line type noise filter eliminates a high-frequency component of DC voltage applied to the signal input terminal and outputs it from the signal output terminal. A first power supply line pattern, formed on a printed-circuit board, connects an output terminal of the power supply circuit with the signal input terminal of the transmission line type noise filter. A second power supply line pattern connects the signal output terminal of the transmission line type noise filter with a power supply terminal of the microprocessor. A ground land pattern is connected with an external ground potential through via holes and makes a connection between the two ground terminals.

Abstract: A power supply circuit produces a supply voltage to be supplied to a microprocessor which is an integrated circuit. A transmission line type noise filter includes a signal input terminal, a signal output terminal and two ground terminals corresponding respectively to the signal input terminal and the signal output terminal. The transmission line type noise filter eliminates a high-frequency component of DC voltage applied to the signal input terminal and outputs it from the signal output terminal. A first power supply line pattern, formed on a printed-circuit board, connects an output terminal of the power supply circuit with the signal input terminal of the transmission line type noise filter. A second power supply line pattern connects the signal output terminal of the transmission line type noise filter with a power supply terminal of the microprocessor. A ground land pattern is connected with an external ground potential through via holes and makes a connection between the two ground terminals.

Abstract: A management system for a copying machine includes a detection circuit for determining whether the information representing a department of the user recorded on a magnetic card is properly read and for providing an operation signal to the copying machine to make it operable. A memory unit having a plurality of storage locations counts a pulse signal generated by the copying machine everytime a copy is produced and stores the date indicative of the total number of produced copies at a storage location assigned in accordance with the read-out information of a department. The total number of copies produced by each of different departments of users is displayed together with the indication of the department by a visual display unit.