Abstract: A power supply apparatus connected via a bus line to another power supply apparatus includes a voltage generation circuit generating a voltage, an abnormality detection circuit detecting an abnormality of the power supply apparatus including the abnormality detection circuit and outputting an abnormality detection signal, an abnormality control circuit, and an interface circuit receiving the abnormality detection signal from the abnormality detection circuit to output the signal via the bus line to another power supply apparatus, and receiving the abnormality detection signal via the bus line from another power supply apparatus to output the signal, to the abnormality control circuit and the abnormality control circuit controlling the voltage generation circuit to stop generation of the voltage in a case where receiving the abnormality detection signal from the abnormality detection circuit or in a case where receiving the abnormality detection signal from the interface circuit.

Abstract: A switching regulator which does not require a capacitor having large time constant as a soft start circuit, reduces variation of the soft start time and the time until a start of a power source voltage stabilizing control The output voltage signal of the soft start circuit is set to a step voltage signal which increases or decreases stepwise at a predetermined rate. A changing period of the step voltage signal is set to a predetermined period after a power source is turned ON. The changing period of the step voltage of the output signal of the soft start circuit is made larger than the predetermined period according to a timing of changing of the PWM pulse output from “H” to “L” or “L” to “H” after an initial period, and after the power source is turned ON by monitoring the PWM pulse output by a detection circuit.

Abstract: A switching regulator which does not require a capacitor having large time constant as a soft start circuit, reduces variation of the soft start time and the time until a start of a power source voltage stabilizing control The output voltage signal of the soft start circuit is set to a step voltage signal which increases or decreases stepwise at a predetermined rate. A changing period of the step voltage signal is set to a predetermined period after a power source is turned ON. The changing period of the step voltage of the output signal of the soft start circuit is made larger than the predetermined period according to a timing of changing of the PWM pulse output from “H” to “L” or “L” to “H” after an initial period, and after the power source is turned ON by monitoring the PWM pulse output by a detection circuit.

Abstract: A power supply apparatus connected via a bus line to another power supply apparatus includes a voltage generation circuit generating a voltage, an abnormality detection circuit detecting an abnormality of the power supply apparatus including the abnormality detection circuit and outputting an abnormality detection signal, an abnormality control circuit, and an interface circuit receiving the abnormality detection signal from the abnormality detection circuit to output the signal via the bus line to another power supply apparatus, and receiving the abnormality detection signal via the bus line from another power supply apparatus to output the signal, to the abnormality control circuit and the abnormality control circuit controlling the voltage generation circuit to stop generation of the voltage in a case where receiving the abnormality detection signal from the abnormality detection circuit or in a case where receiving the abnormality detection signal from the interface circuit.

Abstract: In a step-up/step-down DC-DC converter, an error signal commensurate with a difference between a voltage commensurate with the output voltage and a predetermined reference voltage and a triangular wave signal are compared by a first comparator, whose output is used to turn on and off a step-up switching circuit. An inverted signal obtained by inverting the error signal and the triangular wave signal are compared by a second comparator, whose output is used to turn on and off a step-down switching circuit. The median level between the outputs of the first and second comparators is set to be lower than the maximum level of the triangular wave signal and higher than the minimum level thereof. Thus, when step-up and step-down modes are switched from one to the other, an overlap period is produced during which the step-up and step-down modes overlap. This makes possible smooth switching between the step-up and step-down modes.

Abstract: In a step-up/step-down DC-DC converter, an error signal commensurate with a difference between a voltage commensurate with the output voltage and a predetermined reference voltage and a triangular wave signal are compared by a first comparator, whose output is used to turn on and off a step-up switching circuit. An inverted signal obtained by inverting the error signal and the triangular wave signal are compared by a second comparator, whose output is used to turn on and off a step-down switching circuit. The median level between the outputs of the first and second comparators is set to be lower than the maximum level of the triangular wave signal and higher than the minimum level thereof. Thus, when step-up and step-down modes are switched from one to the other, an overlap period is produced during which the step-up and step-down modes overlap. This makes possible smooth switching between the step-up and step-down modes.

Abstract: The invention provides a load driver circuit including at least one FET such as MOSFET QX, QY, and QZ, controlled by a control circuit providing gate control voltage to the load driving FET by means of a feedback loop connecting the FET and the control circuit, without utilizing any resistor connected in series with the load to detect the load current. This is done by detecting, as a measure of the load current Io, the drain-source voltage drop of the load driving FET QX-QZ by means of detection means 13, 14, and 15. Because the control circuit utilizes no resistor, but utilizes a MOSFET instead, in detecting load current Io, the invention advantageously has a compact form, requiring only a minimum space for connection with external components, cuts down significant power loss that would be otherwise entailed by a current detection resistor, is capable of detecting the load current at high precision, thereby allowing precise control of the load current, and provides an improved wide output dynamic range.

Abstract: In a pulse generator, a sawtooth-shaped wave generator circuit generates a sawtooth-shaped wave by charging and discharging a capacitor. The sawtooth-shaped wave is fed to a comparator that performs pulse-width modulation on it in accordance with the voltage it receives via a terminal and thereby produces pulses. The comparator has its output grounded through a transistor that is turned on with appropriate timing by the sawtooth-shaped wave generator circuit. Thus, the maximum duty factor of the output pulses is made equal to the duty factor of the sawtooth-shaped wave.

Abstract: In a semiconductor integrated circuit device using a MOS type transistor as a transistor for the output of a great current, the source and drain of the transistor is formed by connecting in parallel a plurality of source regions and drain regions surrounded by a gate electrode.

Abstract: A power supply apparatus for stepping up an input voltage and for outputting a constant voltage includes an inductance element and a first transistor connected in series between an input terminal and an output terminal, a second transistor connected between a node between the inductance element and the first transistor and a reference potential, and a voltage holding element connected between the output terminal and the line of the reference potential. The first and second transistors are alternately rendered conductive in accordance with an output voltage from the output terminal while the voltage holding element is charged, so that the voltage of the power supply is stepped up.

Abstract: A DC motor control circuit which contains a DC motor as a part of bridge resistance constituting a bridge circuit includes a first terminal connected to one end of the DC motor in the bridge circuit. A switching transistor is connected to the first terminal. A second terminal is connected to the other end of the DC motor. A switching control circuit detects an unbalanced condition of the bridge circuit via the second terminal and controls the switching period of the switching transistor so as to restore the bridge circuit to a predetermined unbalanced condition or balanced condition. A part of the bridge circuit, the switching transistor and the switching control circuit are integrated into an IC, thereby the number of terminals for the IC is reduced and a coil and an externally added capacitor both for smoothing are unnecessary.

Abstract: In a pulse generator, a sawtooth-shaped wave generator circuit generates a sawtooth-shaped wave by charging and discharging a capacitor. The sawtooth-shaped wave is fed to a comparator that performs pulse-width modulation on it in accordance with the voltage it receives via a terminal and thereby produces pulses. The comparator has its output grounded through a transistor that is turned on with appropriate timing by the sawtooth-shaped wave generator circuit. Thus, the maximum duty factor of the output pulses is made equal to the duty factor of the sawtooth-shaped wave.