Alternative traditional low input voltage high power switch mode DC/DC converters with N-channel MOSFETs require a second regulator circuit to provide the 5V gate drive needed for logic level MOSFETs. Conversion efficiencies for the LTM4611 at full load (15A) are 92% for 3.3VIN to 2.5VOUT, 88% for 2.5VIN to 1.5VOUT, and 81% for 1.5VIN to 0.9VOUT. Applications include systems with only 3.3V, 2.8V or 2.5V as the main power rail such as compact data storage and RAID systems, ATCA and optical networking cards, as well as medical and industrial equipment.
The LTM4611 includes the main DC/DC power circuit and the gate drive circuit plus inductors, MOSFETs, input and output bypass capacitors and compensation circuitry in a small 15mm x 15mm x 4.32mm LGA (Land Grid Array) package weighing only 2.6g. The device boasts ±2% total DC output error over temperature, including line and load regulation as a result of its architecture, precision reference voltage and differential remote sense amplifier — a key specification for loads such as FPGAs and ASICs that require better than ±3% voltage accuracy for optimum performance. To increase output capability to 30A, 45A or 60A, two, three or four LTM4611 DC/DC µModule devices can be paralleled to share current.