Power Supply Unit for Application Microprocessors

ON Semiconductor (Nasdaq: ONNN), a leading supplier of power management solutions, today introduced the NCP1526. This high efficiency synchronous dc-dc buck (step-down) converter features an integrated low noise LDO. Offered in a unique 0.55 mm ultra-thin DFN package, it is ideal for portable applications. The device is designed to power an application microprocessor in multimedia portable devices such as portable media players (PMP), MP3 players and either DMB or DVB-H mobile TV chipsets in cellular phones. This new NCP1526 integrated buck converter accepts input voltage from 2.7 volts (V) to 5.2 V, and features a 3.0 megahertz (MHz) buck converter that supplies a fixed output voltage with current capability of 400 milliamp (mA). The NCP1526 delivers fast transient response, making the converter ideal to power the digital core of a portable microprocessor. The device’s integrated LDO provides a 150 mA current capability and its low noise characteristic enables it to power radio frequency (RF) sensitive analog circuitry. Adding new functions to portable products requires the power device to have a small footprint as well as a thin profile. The high frequency oscillator in the NCP1526 converter dramatically reduces the size of external components. In fact, a very small surface mount inductor of value between 1 micro Henry (µH) to 4.7 µH is recommended. The device’s integrated synchronous rectifier maximizes efficiency and minimizes solution part count. The integrated regulators are packaged in a footprint of only 3 mm x 3 mm, thus saving 50 percent of board space compared to a two-chip solution. To ensure optimal component size and safe operation, value added features like soft-start, cycle-by-cycle current limiting, and thermal shutdown protection have also been integrated. “The NCP1526 is the first integrated converter on the market that is housed in an ultra thin 0.55 mm UDFN package, which is thinner than a flip-chip package and fits nicely into a slim portable design,” said Marie Capron, ON Semiconductor’s director of Low Voltage Power Management products. “It allows designers to differentiate their products by adding an extra application processor anytime, without waiting for the upgrade of the power management unit. In the fast-turning portable market, this design flexibility helps reduce board re-design time and enables manufacturers to get their new, slim models with extra functions to the market faster than their competitors.” The NCP1526 offers a fixed output of 1.2 V from the converter and 2.8 V from the LDO. Other output voltage options are available upon request. The device is offered in a Pb-free, 3 mm x 3 mm x 0.55 mm ultra-thin DFN-10 package. It is priced at $0.90 per unit in 3,000 unit quantities.