Is there anything that can do this?

[technix]

Purpose: a digitally-controller multi-phase buck converter module rated for up to 50A output.

Requirement: switching high current at a high frequency.

Input voltage: 24V maximum
Switch current: 20A maximum
Switch frequency: 600kHz, 720kHz or 1.2MHz (from STM32F334 HRTIM peripheral)

This module is intended to be part of a blade server system, so physical size is a major limiting factor. That is why I am using that high frequencies, so the inductors can be smaller. The controller chip STM32F334 limited me to 3-phase synchronous rectifying buck design.

[technix]

What output voltage are you looking at?
If you are looking to generate Vcore for a CPU, forget about it. It's not just about a stable voltage. It required DVFS, which required extremely fast control loop.

If you are after 24V->12V or 24V->5V or 24V->3.3V, then you can build one.

It is 24V->0-20V adjustable over I2C or CAN with default to 3.3V.

What I need here is that specific switching element that can operate at that speed and current level.

[technix]

What output voltage are you looking at?
If you are looking to generate Vcore for a CPU, forget about it. It's not just about a stable voltage. It required DVFS, which required extremely fast control loop.

If you are after 24V->12V or 24V->5V or 24V->3.3V, then you can build one.

It is 24V->0-20V adjustable over I2C or CAN with default to 3.3V.

What I need here is that specific switching element that can operate at that speed and current level.

SIC770 from Vishay, 2~3 phases.

Those DrMOS looked interesting, and I am going to look into them.

When I went to Electronica Shanghai this year people pointed me at GaN parts though, if I want to run the switching elements at 1.2MHz, but finding or buying them... DrMOS like those seem to be able to run at 750kHz. Now how big of an inductor do I need? How do I estimate the inductor (since, again, size is at premium for my purpose.)

The power module in question actually is one of my basic functionality modules which will be deployed in multiple future projects.