No assignee for this patent application has been made.
Reporters obtained the following quote from the background information supplied by the inventors: "This disclosure relates to power converters. In particular, this disclosure relates to a step down (buck) power converter with inductor based switching, suitable for use with a memory device (e.g., a flash memory device) or other device.
"Continual development and rapid improvement in semiconductor manufacturing techniques have led to extremely high density memory devices. The memory devices are available in a wide range of types, speeds, and functionality. Memory devices often take the forms, as examples, of flash memory cards and flash memory drives. Today, capacities for memory devices have reached 64 gigabytes or more for portable memory devices such as Universal Serial Bus (USB) flash drives, and one terabyte or more for solid state disk drives. Memory devices form a critical part of the data storage subsystem for digital cameras, digital media players, home computers, and an entire range of other host devices.
"One important characteristic of a memory device is its power consumption. In an age when many host devices are powered by limited capacity batteries, every fraction of a watt in power saving translates into extended battery life and extended functionality between recharges for the host device. While the memory device is in operation, a power converter provides the power supply to the memory device. A buck power converter typically has much higher efficiency than other types of power converters. This is one reason that buck converters are frequently preferred over linear regulators and charge pump regulators.
"However, memory devices present significant technical challenges to the use of a buck regulator. As one example, the form factor of the circuit board in a memory device is often very small. As a result, it is difficult to find space for large off-chip components like the inductor or capacitor used in a buck regulator. Furthermore, the components add extra cost to the memory device, and cost margins for memory devices are already very small.
"The sizes of the inductor and capacitor are inversely proportional to the switching frequency of the control loop in the buck regulator. According, in the past, very high switching frequencies on the order of tens or hundreds of MHz or higher were used. Unfortunately, high switching frequencies increase design complexity and cost, while reducing the overall power efficiency. Moreover, the bandwidth of the components of a buck regulator is generally preferred to be significantly higher (e.g., 10 times or higher) than the switching frequency. This is often a difficult condition to meet, and commonly imposes significant restrictions on the maximum possible switching frequency.
"One technique for addressing the technical challenges associated with buck converters is to use a multiphase approach with multiple control loops. Each phase requires its own distinct inductor and switching power transistor pairs. The control loops are driven 180 degrees out of phase. Separate pulse width modulated (PWM) signals drive the distinct power transistor pairs. In other words, the conventional multiphase approach requires multiple inductors equal in number to the number of phases. The convention approach also requires multiple power transistor pairs. As noted above, it is difficult and financially prohibitive to provide these extra components, particularly in a small, inexpensive memory device."
In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "A buck power converter creates a desired output voltage from a greater input voltage, without requiring multiple inductors or capacitors. The buck power converter has a higher efficiency than linear regulators or charge pumps. The buck power converter uses techniques that reduce the sizes of the inductor and capacitor so that they can be integrated on-chip or in-package or on board.
"A signal converter in the buck power converter determines the duty cycle of a switching control signal. The signal converter outputs a modified (multiphase) switching control signal that includes multiple separated on-periods that taken together approximate the duty cycle of the switching control signal while maintaining the same control loop frequency. The multiphase switching signal drives the power switching circuit to provide current to the inductor and capacitor during each of the multiple separated on-periods. The output voltage ripple decreases by a factor of the number of phases in the modified switching signal. In this way, when the ripple amplitude is kept same, the sizes of the passive components may be reduced by the factor of the number of phases in the modified switching control signal.
"Other features and advantages of the inventions will become apparent upon examination of the following figures, detailed description, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
"The system may be better understood with reference to the following drawings and description. In the figures, like reference numerals designate corresponding parts throughout the different views.
"FIG. 1 illustrates a buck power converter.
"FIG. 2 shows a power switching circuit.
"FIG. 3 shows a power switching circuit.
"FIG. 4 shows a signal diagram including a modified (multiphase) switching signal.
"FIG. 5 shows a signal diagram including a modified (multiphase) switching signal.
"FIG. 6 shows a signal diagram including a modified (multiphase) switching signal.
"FIG. 7 shows a signal diagram including a modified (multiphase) switching signal.
"FIG. 8 shows one example of logic for determining the duration of two phases in a modified switching signal.
"FIG. 9 shows a flow diagram of logic for generating a specific nominal output voltage V.sub.o."
For more information, see this patent application: Pancholi, Deepak; Odedara, Bhavin. Multiphase Low Lc Buck Regulator. Filed
Keywords for this news article include: Patents.
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
Most Popular Stories
- Ukraine Crisis Limits Losses in Gold, Silver
- Big Earthquake Rumbles Northern California
- Chiquita, Fyffes to Form Top Banana
- Tesla's Alt-Energy Future Aims for Massive Lithium-Ion Battery Production
- FAA to Appeal Court Decision Allowing Commercial Drone Use
- China's Money Rate Drops on Slowdown Concern
- New Chat App, Yik Yak, Causes Problems for Students
- Mt. Gox Files for Bankruptcy in U.S.
- Obama Meets with Ukraine Prime Minister Wednesday
- Rand Paul Tops Presidential Straw Poll at Conservative PAC Conference