Phase controllers support AI server and graphics card innovations

Alpha and Omega Semiconductor Limited has unveiled its AOZ73016QI, a 16-phase, two-rail controller specifically designed to NVIDIA's latest OpenVReg16 (OVR16) specifications. The controller design is based on the company's high-performance, proprietary AOS Advanced Transient Modulator (A2TM) control scheme. In addition to supporting all the basic needs of the OVR16 specification, the new controller provides value-added features such as RDS(on) and DCR sensing for current monitoring and balance. These features allow the controller to support DrMOS and Smart Power Stages (SPS) in delivering a complete AI server and graphic card power solution along with increased design flexibility.

The control scheme provides excellent current balance at all load conditions and during fast load transients, which is a critical necessity for power-hungry AI and graphics SoCs that demand several thousands of amperes of peak current. It also capably manages phase doubling or tripling without the addition of a phase doubler so that a single controller can support up to a 48-phase design. When paired with the company's high-performance DrMOS and SPS power stages using its highly efficient and robust trench MOSFET, the solution provides industry-leading efficiency and thermals, saving several hundred watts of power during high transient current events that can last for a few 100s of microseconds and up to one millisecond when the SoC draws peak power. In a head-to-head comparison against a leading competitor product, each of the company's 5 x 5 DrMOS power stages was shown to dissipate 14W lower power loss during these peak current events.

The device supports an accurate RDS(on) sensing scheme, which

employs power stage low side MOSFET RDS(on) sensing, allowing low DCR inductors to help boost system efficiency. The device's APM and DCM power-saving features extend its usability to graphics cards and gaming laptops.

The AOZ73016QI offers full programmability via the PMBUS interface and is also AVS bus compliant. The device features digitally programmable voltage and current regulation loops, minimising the external components required to implement a solution. It supports electronic control system (ECS) programmability with the ability to update configuration in the field and to pre-program up to six configuration settings with a pin-strap selection.

"AOS has a long history of developing leading-edge personal computing, server and datacenter solutions. The launch of our successful AOZ73016QI 16-phase controller for OVR16-based designs is the culmination of several years of R&D investment in multiphase controllers. Developed in close collaboration with our customer's system architects, the AOZ73016QI is a robust, reliable power solution for more advanced AI servers. Plus, the design flexibility afforded by the AOZ73016QI helps lower TCO for next-generation AI servers," said Ralph Monteiro, senior. VP, Power IC and Discrete Product lines at AOS.