Electronic Design


DC-DC Converters Don't Need A Heatsink For Full Operation
The NML series of isolated 2-W, single-output dc-dc converters can operate between −40°C and 85°C without a heatsink or any other external cooling device. These devices feature a 2.01-W/cm3 power density in a 1.05-cm2 footprint. They also can be configured to provide isolated negative rails in systems where only positive rails exist, thanks to their 1-kV dc galvanic isolation. An industry-standard 4-pin SIP pinout simplifies upgrades to existing designs as well.

Available with nominal 5- or 12-V inputs, the NML converters have an approximate efficiency rating of 85%. Their nominal load regulation ranges from 3.7% to 7.0%, depending on the model. No external components are necessary for operation, which optimizes PCB utilization. They have MTTF ratings of up to 2 million hours. An internal SMD construction features ceramic capacitors instead of electrolytic or tanatalum capacitors for maximum reliability. Encapsulated in UL 94V-0 packaging material, these devices incorporate a toroidal magnetic design for external field minimization.

Models in the NML series cost $9.58 each in quantities greater than 2500 pieces. Custom designs based on the NML technology also are available.

Newport Components Inc., 8917 Glenwood Ave., Raleigh, NC 27612; (919) 571-9405; fax (919) 571-9262; Internet: www.newport-comps.com.

15-W DC-DC Converters Feature A 4:1 Input Range
Models in the 15-W BR series of dc-dc converters are packaged in a 1.0- by 2.0- by 0.43-in. copper case. They feature a 4:1 input range of 9 to 36 V dc or 18 to 72 V dc. With these devices, OEMs can qualify one converter for applications ranging from 12-V battery power to 24-V industrial bus power. Output voltages of 2.5, 3.3, 5, 12, and 15 V dc are available. These converters also have a ±2% output voltage accuracy and a typical 0.1% load regulation. The typical line regulation is 0.02%, while the typical output noise is 100 mV p-p.

Also, they have a 50-ppm/°C temperature coefficient and a 400-kHz switching frequency. Efficiency can reach 84%. The 9- to 36-V models and the 18- to 72-V models have 700-V dc and a 1500-V dc input-to-output isolations, respectively. Their case operating temperature ranges from −40°C to 100°C, with a 15°C/W thermal impedance. A thermally conductive potting compound encapsulates the units, enabling them to withstand a normal water wash.

These converters cost $38.85 each in 1000-unit lots. They're available from stock.

Calex Manufacturing Co. Inc., 2401 Stanwell Dr., Concord, CA 94520-4841; (800) 542-3355; fax (925) 687-3333; www.calex.com.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.