New Industry Products

Alpha and Omega Semiconductor Debuts a DC/DC Controller for 5G Applications

September 02, 2021 by Gary Elinoff

The Dual Output 3+1 Phase Digital VCOT controller provides power for 5G subsystems including the CU, DU, and RU platforms.

The AOZ97774 is a digital dual output multiphase controller that is itself powered from a single 3.3V supply and is devised to support multiple telecom and general-purpose platforms.

Application Circuit for the 3+1 AOZ97774 with its 4 associated smart power stages. Image courtesy of datasheet

The AOZ97774 is a 3+1 Phase Digital VCOT, dual-channel digital controller aimed at powering processors, FPGAs, ASICs, or MPU/CPUs. The unit features AOS’s proprietary Digital COT architecture. This feature makes ultra-fast load transient response possible. It also enables stable and low voltage ripple control while utilizing only small-sized ceramic capacitors. This allows for reduced board space and for lower final OEM costs.

It also incorporates the specific features necessary to meet Intel VR13 infrastructure applications, and the controller incorporates the SVID Digital High-Speed interface.


Programming and Control

The AOZ97774 is programmable through its PMBus interface and can store these configurations in non-volatile memory NVM, which has a read/write capability of 1,000 times. Designers will find this feature to be extremely useful during the design and debug.

Additionally, the unit can hold as many as 15 custom configurations in the ROM, which are selectable via pinstrapping. This capability allows for a single controller to act as 15 separate power designs.

It incorporates specific features necessary to meet Intel VR13 infrastructure applications, and the controller incorporates the SVID Digital High-Speed interface.


Powering Smart Power Stages

The AOZ97774QE provides power conversion from the 12VDC power rail down to point-of-load (POL) voltages for the subsystems of the 5G wireless network, including the critical control unit (CU), the digital unit (DU), and radio unit (RU) subsystems. The part is relevant for many applications where multi-phase power is required, at three phases or less.

The AOZ97774 is designed for use with AOS smart power stages (SPS) such as the 90A AOZ5276, the 60A AOZ5277, or the 70A (80A peak) AOZ5273. Supporting IMON/TMON inputs, the units will also complement competitor SPS.

In the application circuit diagram depicted earlier, when employing AOZ5276 SPS units, the three-phase output can support 240A peak, while the second uniphase output will peak at 80A. AOS mentions that more typically, relevant designs will call for loads of from 25 to 50 amps per phase.

As per Daniel Lenskold, Director of Digital Power Marketing at AOS. “The AOZ97774QE and companion, Smart Power Stage, offer a highly flexible and configurable solution for Information Infrastructure applications including Wireless and Wired Networking, Optical Communication, Server, Cloud Computing, and General-Purpose applications including FPGA and ASIC power.” He goes on to state that, “The 15 configurations allow for fast time to market and minimizes the number of part numbers required to support a large portfolio of customer products.”


Important features

  • Digital Voltage Mode Constant On-Time Control

  • VR13 compliant with 25MHz SVID bus (rev1.7)

  • Vout accuracy of 0.5%

Protections included for:

     ○ Overvoltage

     ○ Undervoltage

     ○ Overcurrent

     ○ Overtemperature

  • Automatic DPM – Dynamic Phase Management

  • The black-box fault recorder retains fault information in NVM



In addition to generalized DC/DC applications, the AOZ97774QE supports:

  • 3-phase applications
  • Intel VR13 platforms
  • ASIC and FPGA power requirements
  • 5G Wireless
  • Optical Communications
  • Networking



  • The device is available in 5 x 5mm QFN-40L package