Energy harvesting with miniature step-up transformers

October 30, 2013 // By Paul Buckley
Coilcraft has released 6x6 mm LPR6235 Series coupled inductors for use as step-up or flyback transformers in DC-DC converters or as autotransformers.

The devices are sutiable for voltage step-up in energy harvesting applications and have been selected by Linear Technology for the company's LTC3108 and LTC3109 ultralow voltage step-up converter and power managers.

The compact, shielded parts measure 6 mm square by 3.5 mm high, feature a high coupling coefficient (k = 0.95) and are available with five turns ratios from 1:10 to 1:100 for a variety of voltage step-up and step-down applications. The devices offer 300V winding-to-winding isolation and their combination of high Isat and low DCR provides high efficiency and current handling in a rugged, low-cost design. Coilcraft also offer an even smaller LPR 4012 Series transformer that measures 4 mm square by 1.1 mm high.

Both versions have a maximum reflow temperature of 260°C. They feature silver-palladium-platinum-glass frit terminations. COTS Plus tin-silver-copper and tin-lead terminations are also available.

More information about the LPR6235 Series coupled inductors and LPR 4012 Series transformer at www.coilcraft.com/lpr6235.cfm and www.coilcraft.com/lpr4012.cfm