Date
12/04/2014
PDF
LTM4639 20A DC/DC step-down µModule (micromodule) regulator
Linear Technology introduced the LTM4639, a 20A DC/DC step-down µModule (micromodule) regulator capable of converting 2.5V to 7V main-power system rails to point-of-load voltages as low as 0.6V with optimum efficiency. In complex rack-mount systems, improved voltage conversion efficiency results in savings in energy consumption, thermal management and equipment size. Applications include cloud-based equipment and RAID systems where 3.3V is preferred as the main power distribution rail.
The LTM4639 is a complete switching point-of-load power supply and includes the inductor, MOSFETs, DC/DC controller and compensation circuitry. It is housed in a 4.92mm height BGA package with a 15mm x 15mm footprint. For 3.3V input to 1.5V output conversion at 20A load, efficiency is 88%, power loss is 3.9W, and junction temperature rise above ambient temperature is 37°C. The micromodule regulator provides a precise output voltage regulation: total DC error of maximum ±1.5%, guaranteed from -40°C 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 LTM4639’s input supply range is 2.375V to 7V. For operation from 3.3V and lower, a 5V low power auxiliary supply is needed to bias internal circuitry. Output voltage ranges from 0.6V to 5.5V, with protection functions for overcurrent and overvoltage conditions.
