As rack-mount systems increase in complexity, improved voltage conversion efficiency shows savings in energy consumption, thermal management and equipment size. Cloud-based equipment and RAID systems, where 3.3V is preferred as the main power distribution rail, are placing demands on system power conversion, which are met by the LTM4639. This is a 20A DC/DC step-down μModule regulator from Linear Technology, capable of converting 2.5 to 7V main-power system rails to point-of-load voltages as low as 0.6V.

The regulator includes the inductor, MOSFETs, DC/DC controller and compensation circuitry in a 4.92mm height BGA package which has a 15 x 15mm footprint. For 3.3V input to 1.5V output conversion at 20A load, efficiency is 88%, power loss is 3.9W, says the company. Junction temperature rise above ambient temperature is 37°C. The regulator provides total DC error of maximum ±1.5%, guaranteed from -40 to 125°C.  Up to four devices can be paralleled for up to 80A output while operating out-of-phase to reduce the number of input and output capacitors.

The input supply ranges from 2.375V to 7V. (For operation from 3.3V and below, a 5V low power auxiliary supply is needed to bias internal circuitry.)