Power-One has a range of sixteenth-brick DC-DC converters which provide outputs from 1.2 to 5Vdc, rated up to 25A.

Efficiencies exceed 90%, and regulation is +/-3% combined line, load, and temperature, said the supplier.

The SSQE48T series converters feature rugged designs that provide up to 16.23 million hour MTBFs (calculated as per Telcordia TR-332, Method I Case 1) and the capability to withstand a 100V input transient for 100ms.

The converters have a 36 to 75Vdc input range, the capability to start up into pre-biased loads, no minimum-load operation, meets EN 60950 Basic Insulation requirements, and UL94 V-0 flammability rated.
Protections include: hiccup-mode overcurrent, output overvoltage, input undervoltage lockout, and over-temperature shutdown with hysteresis.

Interface and trim capabilities include: remote sense, remote ON/OFF (positive or negative logic option), and +10%/-20% output voltage trim ranges with industry-standard trim equations. 

SSQE48T through-hole-mount converters utilize a DOSA-compliant 22.9x33mm sixteenth-brick footprint, and a profile of 9.5mm. 

See http://www.power-one.com