Patent application number | Description | Published |
20100052628 | Circuit and Method for Reducing Output Voltage Transients in a Voltage Mode Buck Converter - A voltage control mode buck converter circuit includes a feedback amplifier providing a comparison signal and a storage circuit in communication with the comparison signal to store a storage comparison signal value. The storage circuit stores the operating conditions for the circuit during normal continuous conduction mode operation in response to sensing a load drop for the circuit. A switching circuit locks the feedback amplifier into the stored operating parameters while the converter circuit operates in non-continuous conduction mode. When the circuit transitions back into the continuous conduction operation mode, the feedback amplifier is already operating at conditions that are compatible with a continuous conduction operation mode. | 03-04-2010 |
20100188061 | METHOD AND APPARATUS FOR SWITCHING A SYNCHRONOUS DC/DC CONVERTER BETWEEN A PWM MODE OF OPERATION AND A LIGHT-LOAD MODE OF OPERATION - A synchronous buck converter operates in a PWM mode of operation and switches to light-load mode of operation under a light-load condition. When operating in the light-load mode, the synchronous buck converter transitions between a burst mode and an idle mode of operation. In the burst mode of operation, the converter operates with a fixed but increased duty ratio, with respect to the PWM mode of operation, that installs additional energy in an output capacitor. In the idle mode of operation, the high-side and low-side transistors are each turned off. To maximize energy savings and to quickly transition back to the PWM mode of operation if the load increases, a limit as to the number of allowed switching cycles when bursting is imposed and a minimum ratio of the number of clock cycles when idling to the number of switching cycles when bursting is set. Additionally, a comparator is provided to detect a sudden step-increase in the load to quickly switch the converter back to the PWM mode of operation. | 07-29-2010 |
20100253296 | SYMMETRIC SAMPLE AND HOLD OVER-CURRENT SENSING METHOD AND APPARATUS - An over-current condition is detected in a synchronous DC-DC converter by sampling and holding a measured load current value. The load current is sampled while a low-side transistor is ON and then held when the low-side transistor is OFF. The held value is compared to a threshold value while the low-side transistor is OFF. The comparison occurs during the portion of the cycle when the low-side transistor is OFF so that a comparator has sufficient time in which to detect the over-current condition, even in high duty cycle applications. | 10-07-2010 |
Patent application number | Description | Published |
20090279251 | HEAT DISSIPATION DEVICE WITH HEAT PIPE - A heat dissipation device is used for removing heat from at least two adjacent first and second electronic devices in a computer enclosure. The heat dissipation device includes a first heat sink mounted on the first electronic device and a second heat sink mounted on the second electronic device. The first heat sink includes a base, a first fin unit mounted on the base and two heat pipes extending from the base outwardly. Second and third fin units engage with the two heat pipes, respectively. The first, second and third fin units are located adjacent to first, second and third openings of the computer enclosure, respectively. The second heat sink is located among the first, second and third fin units of the first heat sink. | 11-12-2009 |
20100053904 | LOCKING DEVICE FOR HEAT SINK - A locking device is used for securing a heat sink to an electronic device mounted on a first face of a printed circuit board which defines a first hole. The heat sink defines a second hole therein. The locking device has a fastener including a head portion located aside the heat sink, a foot portion located aside a second face of the printed circuit board, and a body portion extending through the holes of the heat sink and the printed circuit board and interconnecting the head portion and the foot portion. The foot portion includes a buckling part abutting against the second face of the printed circuit board, and a positioning part extending toward the head portion to a position above the buckling part. When the buckling part abuts against the printed circuit board, the positioning part has a portion thereof entering into the first hole. | 03-04-2010 |
20100053906 | HEAT DISSIPATION DEVICE - A heat dissipation device for dissipating heat generated by an electronic device on a printed circuit board includes a heat sink and a plurality of mounting devices. A plurality of retaining pillars are secured on the printed circuit board at positions around the electronic device. Each of the mounting devices includes a fixing portion connecting with the heat sink, a mounting portion extending from the fixing portion and a locating portion extending from the mounting portion to a position below the mounting portion. The retaining pillars on the printed circuit board extend through the locating portions and abut against bottoms of the mounting portions to accurately position the heat dissipation device on the electronic device on the circuit board before fasteners are brought to extend through the mounting portions to screw in the retaining pillars. | 03-04-2010 |
20100246127 | HEAT DISSIPATION DEVICE AND METHOD FOR MANUFACTURING THE SAME - A heat dissipation device for dissipating heat from an electronic component mounted on a printed circuit board, includes a fin unit, a centrifugal fan located adjacent to the fin unit, a heat-conducting board attached to the electronic component and a heat pipe thermally connecting the fin unit and the electronic component. An engaging portion protrudes upwardly from a top face of the heat-conducting board. The heat pipe has an evaporating section extending through the engaging portion and being fixed to the top face of the heat-conducting board, and a condensing section attached to the fin unit. | 09-30-2010 |
20110017430 | THERMAL MODULE - A thermal module includes a mounting plate, a centrifugal fan with a fin assembly arranged at an air outlet thereof, and a heat pipe connected the fin assembly with the heat mounting plate. The centrifugal fan includes a fan housing and an impeller rotatably received in the fan housing. The fan housing is disposed immediately neighboring to the mounting plate and mounted to a lateral side of the mounting plate via a securing structure formed between the fan housing and the mounting plate. The fan housing consists of a base and a cover. The base is made of a plastic material. | 01-27-2011 |