Fixed-frequency synchronous buck regulators for noise-sensitive applications

Alpha and Omega Semiconductor Limited has introduced AOZ676xDI series of high switching frequency and simple-to-use synchronous buck regulators. AOZ6762DI and AOZ6763DI can deliver 2A and 3A, respectively, and up to 15W output power. The new devices provide a low on-resistance power stage and are supplied in a 3mm x 3mm DFN 8-lead package with an exposed thermal pad, enabling cooler power conversion for a mixture of consumer and networking equipment such as wireless AP/routers, cable modems, set-top boxes, audio equipment, and LCD TVs.

The power stage consists of two power MOSFETs optimised for efficient synchronous switching to minimise both switching and conduction losses. The new devices can deliver >90% efficiency at full load operation. When working in low output current conditions, the devices run in a proprietary PEM to deliver high efficiency by decreasing switching loss. Under this mode, the regulators can still sustain up to 86% efficiency at 10mA load operation. This feature allows system designers to deliver the low standby power required to meet the 'One Watt Initiative'.

“Features such as high fixed-frequency operation and low minimum controllable on-time of 30ns make AOZ6762DI and AOZ6763DI uniquely suited to noise-sensitive applications such as wireless routers and audio applications,” said Kenny Hu, Power IC marketing manager at AOS. “The thermally enhanced package combined with high efficiency across the whole load range thanks to the pulse energy, light load mode makes this an extremely versatile device for a wide range of applications.”