Patent application number | Description | Published |
20090129768 | CONTROL CIRCUIT FOR SELF-EXCITATION DC/DC CONVERTER, LIGHT EMITTING DEVICE USING SUCH CONTROL CIRCUIT, AND ELECTRONIC DEVICE - A switching transistor is connected to the primary coil of a transformer. A first resistor is provided such that one end thereof is connected to the switching transistor, and the other end thereof is grounded. A first voltage comparator compares a first detection voltage with a first threshold voltage. A second voltage comparator compares a second detection voltage with a second threshold voltage. A switching control unit controls the ON/OFF state of the switching transistor according to the output signals of the first voltage comparator and the second voltage comparator. A first electrode pad through a fourth electrode pad are provided to the respective nodes of the switching transistor and the first resistor. | 05-21-2009 |
20090242734 | CURRENT DETECTION CIRCUIT, PHOTORECEIVER USING THE SAME, LIGHT EMISSION CONTROL DEVICE, AND ELECTRONIC DEVICE USING THE SAME - A first transistor may be provided on a current path of a photo transistor. The bias current path may include a bias switch and a first bias resistor connected in series and is provided in parallel with a main current path including the phototransistor. A second transistor may configure a current mirror circuit with the first transistor, and generates second current formed by multiplying the first current flowing in the first transistor by a predetermined factor. The second current is charged in the charging capacitor and converted into a voltage. The bias current path turns on prior to the start of light reception of the phototransistor and turns off after a predetermined period has elapsed from the start of light reception of the phototransistor. | 10-01-2009 |
20100052767 | SEMICONDUCTOR MODULE - A semiconductor module is provided. Multiple external terminals are connected to an external circuit. Each semiconductor chip includes multiple pads. Wiring lines connect the multiple pads provided to each of the multiple semiconductor chips and the corresponding external terminals or corresponding different pads, respectively. Multiple input terminals of a switch are connected to corresponding internal nodes included within the semiconductor module, and an output terminal thereof is connected to a monitoring terminal provided as an external terminal. The switch makes a connection between the output terminal and one input terminal selected from among the multiple input terminals. | 03-04-2010 |
20120147631 | DC/DC CONVERTER, AND POWER SUPPLY AND ELECTRONIC DEVICE USING THE SAME - A DC/DC converter includes a transformer including primary and secondary coils and an auxiliary coil disposed in a primary coil side; a first output capacitor including a first end having a fixed electric potential and a second end; a first diode disposed in a direction where a cathode of the first diode faces the first output capacitor, between the second end of the first output capacitor and one end of the secondary coil; a switching transistor disposed on a path of the primary coil; a second output capacitor including a first end having a fixed electric potential and a second end; a second diode and a switch disposed between the second end of the second output capacitor and the first port of the auxiliary coil; and a control circuit receiving voltage generated in the second output capacitor through a power supply port and controlling turn-on/off of the switching transistor. | 06-14-2012 |
20120195075 | DIRECT CURRENT/DIRECT CURRENT CONVERTER, AND POWER SUPPLY APPARATUS AND ELECTRONIC DEVICE USING THE SAME - A direct current (DC)/DC converter capable of lowering power consumption and capable of being started in a short time is provided. A voltage generated at a second output capacitor is input to a power supply terminal. An input voltage is input to a high voltage terminal. A charging transistor is a N-channel Metal Oxide Semiconductor Field Effect Transistor disposed between the high voltage terminal and the power supply terminal and applied with a bias so that the charging transistor is normally on. In a first state, in which the voltage of the power supply terminal is lower than a specified first threshold voltage, a current limiting circuit limits a charging current flowing from the high voltage terminal to the power supply terminal, and in a second state in which the voltage is higher than a second threshold voltage, the current limiting circuit lowers the charging current substantially to zero. | 08-02-2012 |
20120201065 | POWER FACTOR CORRECTION CIRCUIT - A first error amplification circuit amplifies a difference between a predetermined reference voltage and a first detection voltage that corresponds to the output voltage of a DC/DC converter, so as to generate a second voltage. A voltage level judgment circuit generates a third voltage having a discrete level that corresponds to the amplitude of a first voltage. A multiplying/dividing circuit multiplies the first voltage by the second voltage, and divides the resulting product by the third voltage, so as to generate a fourth voltage. A comparator compares the fourth voltage with a second detection voltage that corresponds to a current that flows through a switching transistor included in the DC/DC comparator. A driving circuit turns on the switching transistor for each predetermined period, and turns off the switching transistor according to the output of the comparator every time the second detection voltage becomes higher than the fourth voltage. | 08-09-2012 |
20120294046 | POWER SUPPLY APPARATUS - A second control circuit is configured to switch a pulse signal to a level which turns off a second switching transistor when a coil current that flows through a primary winding reaches a predetermined threshold current. The second control circuit is configured to start a switching operation when a power supply for an electronic device is turned on, to set the threshold current to a first value when an intermediate voltage is higher than a predetermined level, and to set the threshold current to a second value that is lower than the first value when the intermediate voltage is lower than a predetermined level. A first control circuit is configured to start a switching operation upon receiving an instruction from a microcontroller to start operating. | 11-22-2012 |
20130027983 | AC/DC CONVERTER, AND AC POWER ADAPTER AND ELECTRONIC APPARATUS USING THE SAME - The present invention provides an Alternating Current/Direct Current (AC/DC) converter employing measures not only against residual voltage but also to reduce power consumption. The AC/DC converter receives an Alternating Current (AC) voltage through a concentric plug and converts the AC voltage into a Direct Current (DC) voltage. A discharge path is disposed on a path from a discharge terminal to a ground terminal. A detection circuit compares a wave detection voltage with a predetermined threshold voltage, and enables the discharge path to be turned on when the wave detection voltage is continuously lower than the threshold voltage for a predetermined detection time. | 01-31-2013 |
20140063865 | DC/DC CONVERTER - A pulse modulator generates a pulse modulation signal S | 03-06-2014 |
20140071715 | DC/DC CONVERTER, CONTROL CIRCUIT AND CONTROL METHOD THEREOF, POWER SUPPLY, POWER ADAPTER AND ELECTRONIC APPARATUS USING THE SAME - A control circuit of a DC/DC converter includes: a pulse modulator configured to generate a pulse signal; and a driver configured to switch a switching transistor based on the pulse signal. The pulse modulator includes an on signal generator to generate an on signal. The on signal generator includes: a bottom detection comparator configured to compare a voltage of one end of an auxiliary winding with a predetermined threshold voltage and generate a bottom detection signal; a first time-out circuit configured to generate a first time-out signal asserted when the bottom detection signal is not asserted; a second time-out circuit configured to generate a second time-out signal asserted when the bottom detection signal is not asserted; and a logic part configured to generate the on signal based on the bottom detection signal, the first time-out signal and the second time-out signal. | 03-13-2014 |
20140160804 | DC/DC CONVERTER - An external resistor is connected to a detection terminal. A pulse modulator is configured to generate a pulse signal S | 06-12-2014 |
20140313792 | POWER DELIVERY DEVICE, AC ADAPTER, AND ELECTRONIC APPARATUS - The PD device comprises a primary-side controller configured to control an input current of a DC/DC converter disposed between an input and an output, and a secondary-side controller connected with AC coupling to the output, and configured to feedback electric power information of the output to the primary-side controller. The primary-side controller varies an output voltage value and an available output current capacity of the DC/DC converter by controlling the input current on the basis of the electric power information fed back from the secondary-side controller. The primary-side controller can change an overpower detecting set value in accordance with the target equipments connected to the output, thereby executing the power change of the DC/DC converter. | 10-23-2014 |
20140313793 | POWER DELIVERY DEVICE, AC ADAPTER, ELECTRONIC APPARATUS AND POWER DELIVERY SYSTEM - The PD device includes: a DC/DC converter disposed between an input and an output; a primary-side controller configured to control an input current of the DC/DC converter; and a secondary-side controller connected with AC coupling to the output, and configured to feed back electric power information of the output to the primary-side controller. The primary-side controller varies an output voltage value and an available output current capacity of the DC/DC converter by controlling the input current on the basis of the electric power information fed back from the secondary-side controller. | 10-23-2014 |
20140313794 | POWER DELIVERY DEVICE AND START-UP METHOD, AC ADAPTER AND ELECTRONIC APPARATUS - The PD device includes: a DC/DC converter disposed between an input and an output; a primary-side controller configured to start up the DC/DC converter; and a secondary-side controller connected to an output of the DC/DC converter, the secondary-side controller AC-coupled to the output, the secondary-side controller configured to feed back electric power information of the output to the primary-side controller and an input of the DC/DC converter, wherein the secondary-side controller controls an input current of the DC/DC converter, thereby varying an output voltage value and an available output current capacity of the DC/DC converter. | 10-23-2014 |
20150023070 | AC/DC CONVERTER - A first rectified voltage obtained by rectifying an AC voltage is input to an input detection terminal of a control circuit. A first NMOS transistor configured as a depletion-type high-voltage element, and its drain is connected to the input detection terminal, and its gate is connected to its source. An AC voltage detection circuit detects the amplitude of the AC voltage based on a current that flows through the first NMOS transistor. | 01-22-2015 |
20150098255 | INSULATION TYPE SWITCHING POWER SOURCE APPARATUS - A power source apparatus comprises: a transformer that insulates a primary system and a secondary system and uses primary/secondary windings to transform an input voltage into an output voltage; a switching control device that is disposed in the primary system to drive the primary winding, and an output monitor device that is disposed in the secondary system to monitor the output voltage. The transformer includes a first auxiliary winding disposed in the primary system and a second auxiliary winding disposed in the secondary system. The output monitor device drives the second auxiliary winding to generate an induced voltage in the first auxiliary winding when the output voltage becomes smaller than a predetermined threshold voltage. The switching control device temporarily stops driving of the first winding upon detecting a light load state and resumes the driving of the first winding upon detecting the induced voltage in the first auxiliary winding. | 04-09-2015 |