Patent application number | Description | Published |
20080284402 | Power Supply Unit and Portable Apparatus Using the Same - A power supply unit comprises a series regulator and a switching DC-DC converter controlled by a PWM signal and connected in parallel with the series regulator, which are switchably enabled by a mode instruction signal depending on the magnitude of a load current. In switching the series regulator and the DC-DC converter, they are simultaneously enabled for a predetermined overlapping time. Further, in changing the operating condition of the DC-DC converter, the width of the PWM signal is shortened to extend the dead time of the DC-DC converter by a predetermined period, thereby suppressing free oscillations and accompanying overshoots that could take place in the power supply unit during switching. | 11-20-2008 |
20090021232 | Switching Regulator - A switching regulator according to the invention includes a resistor (R | 01-22-2009 |
20090033299 | STEP-DOWN TYPE SWITCHING REGULATOR, CONTROL CIRCUIT THEREOF, AND ELECTRONIC DEVICE USING THE SAME - A pulse signal generating circuit generates a pulse signal having a duty ratio controlled such that the output voltage approaches a reference voltage. A driver circuit generates first and second gate voltages, which are to be respectively applied to the gates of a switching transistor and a synchronous rectifier transistor, based upon the pulse signal. A threshold voltage generating unit generates a threshold voltage which is synchronous with the second gate voltage, and which is in the high-level state during a period when the synchronous rectifier transistor is to be turned off and in the low-level state during a period when the synchronous rectifier transistor is to be turned on. A light-load detection comparator compares a switching voltage with the threshold voltage, and outputs a light-load detection signal. | 02-05-2009 |
20090273329 | STEP-DOWN TYPE SWITCHING REGULATOR - A pulse signal generating circuit generates a pulse signal having a duty ratio controlled such that the output voltage approaches a reference voltage. A driver circuit generates first and second gate voltages, which are to be respectively applied to the gates of a switching transistor and a synchronous rectifier transistor, based upon the pulse signal. A threshold voltage generating unit generates a threshold voltage which is synchronous with the second gate voltage, and which is in the high-level state during a period when the synchronous rectifier transistor is to be turned off and in the low-level state during a period when the synchronous rectifier transistor is to be turned on. A light-load detection comparator compares a switching voltage with the threshold voltage, and outputs a light-load detection signal. | 11-05-2009 |
20120126768 | CONTROL CIRCUIT FOR SWITCHING POWER SUPPLY - An error amplifier generates an error signal V | 05-24-2012 |
20120235623 | CHARGING CIRCUIT - A charging circuit receives electric power from a solar battery, and charges a secondary battery. A charging current detection unit generates a detection signal that corresponds to a charging current supplied from a DC/DC converter to the secondary battery. A control circuit generates a reference voltage that corresponds to the detection signal. A driving unit generates a pulse signal having a duty ratio that is adjusted such that the voltage output from the solar battery matches the reference voltage, and performs switching of a switching transistor according to the pulse signal. A control circuit adjusts the reference voltage such that the reference voltage becomes greater. | 09-20-2012 |
20130043851 | CONTROL CIRCUIT AND CONTROL METHOD FOR SWITCHING POWER SUPPLY, AND SWITCHING POWER SUPPLY AND ELECTRONIC APPARATUS USING CONTROL CIRCUIT AND CONTROL METHOD - The present invention improves the efficiency of a switching power supply in a light load. A control circuit is configured to repeat a driving duration enabling the switching element to be switched and a stop duration stopping the switching in a light load state. A pulse signal generating portion generates a driving pulse signal, in which the driving pulse signal at least includes a pulse in the driving duration, and the lighter a load is, the less the number of pulses in the driving duration is. A first driver drives a first switching transistor according to the at least one pulse in the driving pulse signal other than predetermined K pulses (K is a natural number). The K pulses are in the driving pulse signal when the number of the pulses is reduced to K. | 02-21-2013 |
20150015219 | DC/DC CONVERTER - A DC/DC converter comprises: inductors L provided for respective channels; switching circuits provided for the respective channels; and a controller configured to change the number of channels to be activated, i.e., K, according to an amount of a load current I | 01-15-2015 |