The drive toward sixteenth brick form factor began last month when Mansfield, Mass.-based Datel Inc. proposed a footprint and pin spacing to make this standard feasible and workable (see the March 13 issue of PE Tech Times). Toward that goal, the length was shrunk to half, while the width remained the same as in the eighth brick format. Concurrently, Datel unveiled plans to deliver power conversion solutions in this format for 12V and 48V applications with the ability to handle 33W to 50W power. Meanwhile, as Datel designers are prepping dc-dc converters in this new form factor, another major player has taken the sixteenth brick effort a step further. Earlier this month, Astec Power, a major merchant supplier of power conversion solutions, introduced a 50W isolated dc-dc converter solution in the sixteenth brick format, labeled ALX series. Astec’s footprint, however, is slightly different from Datel’s. While preserving the same quarter-brick and eighth-brick pin location but with reduced length, Astec’s newest sixteenth brick is 1.65 in. in length, 0.8 in. in width, and has a 0.33 in. profile. Datel’s proposed format offers 1.3-in. in length and 0.9 in. in width. Interestingly, the sixteenth brick entry into the market comes much earlier than predicted by Pandits. Based on the evolution of bricks, analysts expected sixteenth brick products to come into the market by 2005. However, the pace of development in planar magnetics, coupled with novel topologies and clever circuit techniques, has resulted in this solution sooner than later. One-third smaller than a typical eighth brick converter, Astec’s ALX models squeeze up to 20A output current from this form factor in surface-mount format. This sixteenth brick series handles 36V to 76V input bus voltage to deliver up to 20A at 1.8V and 1.2V outputs. Astec claims the unit offers efficiency as high as 88% for 1.8V model. Because it employs clever layout and thermal management techniques, the ALX converter offers minimal power derating at elevated temperatures. While providing basic insulation from input to output, Astec’s sixteenth brick boasts mean-time-between-failures (MTBF) of more than 1million hours. Other salient features of the new brick include overvoltage, overcurrent, and overtemperature protection. In addition, it implements undervoltage lockout with hysteresis, as well as an output trim pin and enable pin with positive or negative logic controls. The 1.8V output models in the ALX family are sampling now, while the 3.3V, 2.5V, and 1.2V sixteenth bricks will be released later in this quarter. In OEM quantities, the pricing starts at $40.75.
