Abstract: A semiconductor device according to an embodiment of the present disclosure includes an output driver including a first variable resistor element, a replica circuit including a second variable resistor element and having the same configuration as the output driver, a first wiring line coupled to an output end of the replica circuit; a second wiring line electrically coupled to a first external terminal; and a comparator that compares a voltage of the first wiring line with a voltage of the second wiring line.

Abstract: A DC-DC converter 1 is provided with a voltage conversion unit 100 and a control unit 200. The control unit 200 includes: a comparator 20 and a trigger signal generation section 30 which generate a trigger signal when an output voltage is reduced from a reference voltage after having received a minimum off-time signal, a DLL section 40 generating a reference delay signal, a delay section 50 generating delay signals which are delayed from the trigger signal by a predetermined amount, further delayed by an on-time, still further delayed by a second dead time, and yet still further delayed by a minimum off-time, respectively, according to the reference delay signal, and a timing control section 60 determining a start time point and an end time point of an on-pulse, a start time point and an end time point of an off-pulse and also generating a minimum off-time signal, according to these delay signals.

Abstract: A DC-DC converter 1 is provided with a voltage conversion unit 100 and a control unit 200. The control unit 200 includes: a comparator 20 and a trigger signal generation section 30 which generate a trigger signal when an output voltage is reduced from a reference voltage after having received a minimum off-time signal, a DLL section 40 generating a reference delay signal, a delay section 50 generating delay signals which are delayed from the trigger signal by a predetermined amount, further delayed by an on-time, still further delayed by a second dead time, and yet still further delayed by a minimum off-time, respectively, according to the reference delay signal, and a timing control section 60 determining a start time point and an end time point of an on-pulse, a start time point and an end time point of an off-pulse and also generating a minimum off-time signal, according to these delay signals.

Abstract: The comparator-system DC-DC converter 1 comprises the voltage conversion section 100 and the control unit 200. The control unit 200 comprises comparator sections 20 and 40 which compare the output voltage of the voltage conversion section 100 and the reference voltage, and determine a predetermined ON width of the ON pulse or the OFF width of the OFF pulse of the control signal Ssw, and a counter section 60 which counts at least either one of the ON pulses and OFF pulses of the control signal and counts the reference clocks to adjust the predetermined ON width so that the ratio between the count value of the control signal Ssw and the count value of the reference clock is M:N where M and N are natural numbers.

Abstract: A comparator-system DC-DC converter 1 according to an embodiment of the present invention comprises a control unit 200 which has a comparator section 20, 40 which compares the output voltage of the voltage conversion section with a reference voltage and determines a predetermined ON width of the ON pulse of the control signal Ssw or a predetermined OFF width of the OFF pulse of the control signal Ssw, and frequency control means 25 which compares the control signal Ssw with reference clock Cref and adjusts the ON width or OFF width so that the frequency of the control signal Ssw is constant. The frequency control means 25 detects a state where the output current of the voltage conversion section 100 is 0 A or a state where the output current is going to be 0 A and stops the processing to adjust the ON width or OFF width.

Abstract: A power supply apparatus includes a switching regulator, a linear regulator, a timer circuit, a control circuit, an inverter, and a switch. The power supply apparatus is a step-down type DC-DC converter which steps down an input voltage inputted to an input terminal and then outputs an output voltage, which has been stepped down, to an output terminal. The timer circuit counts the time elapsed from when a start of the power supply apparatus is instructed by a control signal, and sets an output signal to a high level at a lapse of a predetermined time. When the output signal goes to the high level, the switch turns on and the output voltage is supplied to a power supply terminal of the control circuit.

Abstract: A control signal generating circuit (1) comprises a comparator (10) for comparing an output voltage VO with a reference voltage outputted from a reference voltage source (11), a flipflop (12) set by the output of the comparator (10), and a pulse control circuit (13) which receives an input voltage VIN, a reference voltage VREF2, and the inverted output of the flipflop (12), sets the on time in accordance with the ratio between the input voltage VIN and the reference voltage VREF2, and resets the flipflop (12) when the on time elapses after the output pulse of the flipflop (12) rises. The output pulse of the flipflop (12) is outputted as a control signal into a driver logic circuit (2). The driver logic circuit (2) performs on/off control of NMOSs (3, 4) according to the control signal. Thus, a switching regulator capable of operating at high speed can be realized.

Abstract: A comparator-system DC-DC converter 1 according to an embodiment of the present invention comprises a control unit 200 which has a comparator section 20, 40 which compares the output voltage of the voltage conversion section with a reference voltage and determines a predetermined ON width of the ON pulse of the control signal Ssw or a predetermined OFF width of the OFF pulse of the control signal Ssw, and frequency control means 25 which compares the control signal Ssw with reference clock Cref and adjusts the ON width or OFF width so that the frequency of the control signal Ssw is constant. The frequency control means 25 detects a state where the output current of the voltage conversion section 100 is 0A or a state where the output current is going to be 0A and stops the processing to adjust the ON width or OFF width.

Abstract: The comparator-system DC-DC converter 1 comprises the voltage conversion section 100 and the control unit 200. The control unit 200 comprises comparator sections 20 and 40 which compare the output voltage of the voltage conversion section 100 and the reference voltage, and determine a predetermined ON width of the ON pulse or the OFF width of the OFF pulse of the control signal Ssw, and a counter section 60 which counts at least either one of the ON pulses and OFF pulses of the control signal and counts the reference clocks to adjust the predetermined ON width so that the ratio between the count value of the control signal Ssw and the count value of the reference clock is M:N where M and N are natural numbers.

Abstract: A direct-current power supply apparatus outputs a predetermined output voltage by lowering an input voltage. The apparatus includes a control element to which the input voltage is inputted, a first resistive element, provided in series with the control element, which outputs the output voltage, and second and third resistive elements, connected in series with each other, which are provided in parallel with the first resistive element. A voltage at a midpoint between the second resistive element and the third resistive element is fed back so as to control the control element.

Abstract: A power supply apparatus includes a switching regulator, a linear regulator, a timer circuit, a control circuit, an inverter, and a switch. The power supply apparatus is a step-down type DC-DC converter which steps down an input voltage inputted to an input terminal and then outputs an output voltage, which has been stepped down, to an output terminal. The timer circuit counts the time elapsed from when a start of the power supply apparatus is instructed by a control signal, and sets an output signal to a high level at a lapse of a predetermined time. When the output signal goes to the high level, the switch turns on and the output voltage is supplied to a power supply terminal of the control circuit.

Abstract: A DC/DC converter in which the DC output set voltage can be raised includes a switching transistor arranged to input an external power supply voltage, a smoothing circuit, a switching control circuit to which the internal power supply voltage is supplied and arranged to control the switching transistor, a comparison circuit arranged to compare the DC output voltage with a first reference voltage and to output a selecting signal, first and second linear transistors arranged to input the external power supply voltage or DC output voltage in accordance with the selecting signal, and to output the voltage according to the internal power supply control voltage as the internal power supply voltage, and an error amplification circuit arranged to input the internal power supply voltage, compare the internal power supply voltage with the second reference voltage, amplify the error thereof, and output the internal power supply control voltage.

Abstract: A switching regulator is provided which allows a switching to an optimum control method according to a set on which it is to be mounted. A power supply apparatus, which is a step-down type DC-DC converter, includes two blocks, namely a control circuit and a switching regulator. The switching regulator includes a switching transistor, a rectifier diode, in inductor and a capacitor. The control circuit generates a drive signal that controls the on and off of the switching transistor. The control circuit includes a fixed frequency control signal generation unit, a fixed ON-time control signal generation unit, a driver circuit and an inverter. Either one of the fixed frequency control signal generation unit and a fixed ON-time control signal generation unit operates according to a selection signal inputted to a selection terminal from the outside, and the other is shut down.

Abstract: A control signal generating circuit (1) comprises a comparator (10) for comparing an output voltage VO with a reference voltage outputted from a reference voltage source (11), a flipflop (12) set by the output of the comparator (10), and a pulse control circuit (13) which receives an input voltage VIN, a reference voltage VREF2, and the inverted output of the flipflop (12), sets the on time in accordance with the ratio between the input voltage VIN and the reference voltage VREF2, and resets the flipflop (12) when the on time elapses after the output pulse of the flipflop (12) rises. The output pulse of the flipflop (12) is outputted as a control signal into a driver logic circuit (2). The driver logic circuit (2) performs on/off control of NMOSs (3, 4) according to the control signal. Thus, a switching regulator capable of operating at high speed can be realized.

Abstract: An electronic apparatus includes a housing and a printed wiring board contained in the housing. The printed wiring board includes a first surface, a second surface and a conductive layer. The first surface has a mounting area, the second surface is located opposite to the first surface in a position corresponding to the mounting area, between the first surface and the second surface. A heat generating component is mounted on the mounting area of the printed wiring board. A reinforcing member is provided on the second surface of the printed wiring board, and is in thermal contact therewith. The heat of the heat generating component is conducted to the reinforcing member through the printed wiring board, and is radiated from the reinforcing member.

Abstract: An electronic apparatus includes a hollow main body. This main body is powered by a fuel cell which generates a vapor-containing gas during operation. The vapor-containing gas generated by the fuel cell is made to flow along a predetermined passage by a cooling fan and is discharged from a discharge port formed in the main body.

Abstract: A DC/DC converter in which the DC output set voltage can be raised includes a switching transistor arranged to input an external power supply voltage, a smoothing circuit, a switching control circuit to which the internal power supply voltage is supplied and arranged to control the switching transistor, a comparison circuit arranged to compare the DC output voltage with a first reference voltage and to output a selecting signal, first and second linear transistors arranged to input the external power supply voltage or DC output voltage in accordance with the selecting signal, and to output the voltage according to the internal power supply control voltage as the internal power supply voltage, and an error amplification circuit arranged to input the internal power supply voltage, compare the internal power supply voltage with the second reference voltage, amplify the error thereof, and output the internal power supply control voltage.

Abstract: An electronic apparatus includes a housing and a printed wiring board contained in the housing. The printed wiring board includes a first surface, a second surface and a conductive layer. The first surface has a mounting area, the second surface is located opposite to the first surface in a position corresponding to the mounting area, between the first surface and the second surface. A heat generating component is mounted on the mounting area of the printed wiring board. A reinforcing member is provided on the second surface of the printed wiring board, and is in thermal contact therewith. The heat of the heat generating component is conducted to the reinforcing member through the printed wiring board, and is radiated from the reinforcing member.

Abstract: In place of an arrangement that terminates a signal input circuit of a signal input buffer on a line of a transmission line part including a circuit board, cables, and the like, a signal output buffer arranged in an output-side electronic device part is directly circuit-connected to a signal input buffer arranged in an input-side electronic device part via a line of a transmission line part including a circuit board, cables, and the like without being terminated. Furthermore, the circuit is terminated by a terminating resistor near the input-side electronic device part via a terminating circuit line extending from that circuit connection part.

Abstract: An electronic apparatus includes a hollow main body. This main body is powered by a fuel cell which generates a vapor-containing gas during operation. The vapor-containing gas generated by the fuel cell is made to flow along a predetermined passage by a cooling fan and is discharged from a discharge port formed in the main body.