Abstract: A protection circuit 2 of a first embodiment comprises a resistance-variable switch 10, an overcurrent detection unit 20, a control voltage application unit 30, a capacity unit 40, a control terminal voltage change unit 50, and an outer terminal 11. The resistance-variable switch 10 has a control terminal 10a, a first terminal 10b, and a second terminal 10c. The control terminal voltage change unit 50 includes a switch 51 and a resistor 52 which are provided in series between the control terminal 10a of the resistance-variable switch 10 and a reference potential terminal.

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: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.

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 switching regulator includes a first switching regulator corresponding to a master channel, and a second switching regulator corresponding to a slave channel. The first switching regulator generates first output voltage Vout1 by a constant on-time system in which on-time is constant. On the other hand, the second switching regulator monitors a first switching signal and a second on-time control circuit determines on-time of a second switching signal in accordance with lapse time from the rising time of the first switching signal to the rising time of a second switching signal.

Abstract: A switching regulator includes a first switching regulator corresponding to a master channel, and a second switching regulator corresponding to a slave channel. The first switching regulator generates first output voltage Vout1 by a constant on-time system in which on-time is constant. On the other hand, the second switching regulator monitors a first switching signal and a second on-time control circuit determines on-time of a second switching signal in accordance with lapse time from the rising time of the first switching signal to the rising time of a second switching signal.

Abstract: A switching regulator includes a first switching regulator corresponding to a master channel, and a second switching regulator corresponding to a slave channel. The first switching regulator generates first output voltage Vout1 by a constant on-time system in which on-time is constant. On the other hand, the second switching regulator monitors a first switching signal and a second on-time control circuit determines on-time of a second switching signal in accordance with lapse time from the rising time of the first switching signal to the rising time of a second switching signal.

Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases.

Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.

Abstract: A DC/DC converter includes a switching element which is opened and closed to supply power from an input power supply Vcc through a coil to an output terminal, which is connected to a load, and to adjust the voltage at the output terminal. The DC/DC converter also includes a coil current detection resistor arranged to detect a coil current, a smoothing capacitor connected to the load side of the coil current detection resistor and arranged to smooth the voltage at the output terminal, a reference current value control circuit arranged to detect the voltage on the coil side of the coil current detection resistor to control a reference current value of the coil current, a clock generator arranged to generate a reference clock, and a feedback circuit arranged to close the switching element in synchrony with the reference clock and to open the switching element when the coil current exceeds the reference current value.

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: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current lo increases.

Abstract: In a power supply apparatus that is so configured as to produce from an input voltage an output voltage Vo within a predetermined permissible variation range, the output voltage Vo is so controlled as to decrease within the permissible variation range as the output current Io increases. This configuration offers an output voltage with an improved transient characteristic against an abrupt variation in the output current and simultaneously permits reduction of the power consumed when the output current increases.

Abstract: A DC/DC converter includes a switching element which is opened and closed to supply power from an input power supply VCC, through a coil to an output terminal, which is connected to a load, and to adjust the voltage at the output terminal. The DC/DC converter also includes a coil current detection resistor arranged to detect a coil current a smoothing capacitor connected to the load side of the coil current detection resistor and arranged to smooth the voltage at the output terminal, a reference current value control circuit arranged to detect the voltage on the coil side of the coil current detection resistor to control a reference current value of the coil current, a clock generator arranged to generate a reference clock, and a feedback circuit arranged to close the switching element in synchrony with the reference clock and to open the switching element when the coil current exceeds the reference current value.

Abstract: A switching regulator includes a first switching regulator corresponding to a master channel, and a second switching regulator corresponding to a slave channel. The first switching regulator generates first output voltage Vout1 by a constant on-time system in which on-time is constant. On the other hand, the second switching regulator monitors a first switching signal and a second on-time control circuit determines on-time of a second switching signal in accordance with lapse time from the rising time of the first switching signal to the rising time of a second switching signal.

Abstract: A power supply circuit relating to the present invention comprises a differential amplifier for feeding out a voltage as a control voltage in accordance with a difference between a feedback voltage commensurate with an output voltage and a reference voltage, an output current control element for feeding out an output current in accordance with the control voltage fed thereto from the differential amplifier, an output line by way of which the output current is supplied to a load, a feedback line by way of which a voltage on the output line is fed back as the feedback voltage to the differential amplifier, the feedback line connected to the output line, and a sink current generating circuit, connected between the feedback line and ground, for generating a sink current by which the control voltage fed to the output current control element is raised to a predetermined value.

Abstract: A power supply circuit relating to the present invention comprises a differential amplifier for feeding out a voltage as a control voltage in accordance with a difference between a feedback voltage commensurate with an output voltage and a reference voltage, an output current control element for feeding out an output current in accordance with the control voltage fed thereto from the differential amplifier, an output line by way of which the output current is supplied to a load, a feedback line by way of which a voltage on the output line is fed back as the feedback voltage to the differential amplifier, the feedback line connected to the output line, and a clamping circuit for maintaining the control voltage so as not drop below a predetermined value.