Alpha and Omega Semiconductor has released 18V input 1.25MHz fixed-frequency synchronous buck regulators with 30ns minimum on-time.

“The low minimum on-time enables low output voltages from a 12V bus, making the device a suitable power converter for next-generation SoCs, FPGAs, and ASICs using deep sub-micron processes,” according to AOS

AOZ6762DI and AOZ6763DI are capable of delivering 2A and 3A, respectively, and up to 15W output power.

Both the internal mosfets are n-channel, with bootstrapping to drive the upper transistor. In both cases the high-side mosfet is 145mΩ, and the synchronous rectifiers are 90 or 80mΩ respectively.

Input can range across 4.5V to 18V, and output from 0.6V to 65% of Vin.

>90% efficiency can be achieved at full load, and a proprietary ‘pulse energy mode’ (PEM) is included to maintain up to 86% efficiency at 10mA load – “this feature enables system designers to achieve the low stand-by power required to meet the One Watt Initiative,” claimed AOS.

Packaging is 3 x 3mm DFN 8-lead package with an exposed thermal pad – thermal rise is 50°C/W into a four layer 2oz copper PCB. 57°C thermal rise at 15W is claimed for both parts.

External compensation is available, allowing transient response and output ripple to be traded with various output filters.

“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 AOS marketing manager Kenny Hu.

Other applications predicted are set-top boxes, cable modems and LCD TVs.