In telecom and data-center applications, dc-dc brick converters' power density keeps going up to match the number of point-of load (POL) converters on the board. The latest in the quarter-brick format (57.9 by 36.8 by 12.7 mm) is Ericsson Power Modules' PKM4000BPI series, which delivers up to 380 W from a 36- to 75-V input range (see the figure).
These converters particularly target designs based on the Advanced Telecom Computing Architecture (ATCA). Features include latching or non-latching protection, a base plate with optional case ground pin, and N+1 parallel operation.
With a regulation of ±10% over all load and line changes, the modules are available in 33 A at 12 V, 25 A at 12 V, and 40 A at 9 V. The 9-V version recognizes the move toward lower intermediate bus voltages.
POL efficiency is related to the step-down voltage ratio. Stepping down from 9 to 1.2 V results in higher POL efficiency than stepping down from 12 V. The tradeoff, of course, is higher conduction loss on the bus.
Typical efficiencies are 96%. Input-to-output isolation is 1500 V dc. The modules meet safety requirements to IEC/EN/UL60950 (approval pending) and offer a mean time before failure of 1.82 million hours.
In thousand-piece quantities, unit prices range from $49.70 to $58.88.
Ericsson Power Modules