CUI Extends Family of Open-frame AC-DC Switchers for Green Technology

December 04, 2019 by Gary Elinoff

CUI has added six new lines of powers supplies, offering 15 watts to 65 watts, to its VOF product family.

CUI Inc has expanded its VOF product family with six new lines to the series: VOF-15C, VOF-30C, VOF-40C, VOF-45CVOF-60C, and VOF-65C. As the digits in their names suggest, they supply 15W, 30W, 40W, 45W, 60W, and 65W, respectively.

Each of the new series is composed of either six or seven members, each offering a number of different voltage-current combinations.


New lines to the VOF product family.

New lines to the VOF product family. Image from CUI Inc


CUI’s VOF product line is an industry mainstay offering outputs ranging from 3W to 550W. Like the VOF-180 and VOF-225 series, which come in 2 x 4-inch open-frame packages, the new series likewise comes in an open-frame package. 


Designed for Green Power Technology

CUI places great store in the fact that the six new series are “green," claiming that the new low-power additions will "meet the growing demand for green power technology."

Because of the small device sizes and power properties, CUI sees the new additions to the VOF series to be useful candidates for industrial, consumer, ITE, and smart home applications.


VOF-15C series.

VOF-15C series. Image from CUI Inc

The series also conform with RoHS and REACH material compliance directives. In addition, they feature UL/EN/IEC 62368-1 certification and are compliant with CISPR32/EN 55032 Class B, while meeting UL/EN/IEC 60335 requirements. 


Notable Device Properties

The new power supplies feature switching frequencies of either 60kHz or 65kHz. All feature no-load power consumption of less than 500mW. The units can all operate from DC input voltages ranging from 100V to 370V and from 85VAC to 264VAC, featuring 3kVAC isolation.


Package Sizes

The series all feature industry-standard footprints and similar package sizes. The VOF-15C series and VOF-30C series are available in a 2.5 x 1.8 x 0.75-inch and 3 x 2 x 1.1-inch packages, respectively. The remaining four series all come in 3 × 2 x 1.2-inch packages.


Output Voltages and Currents

While nowadays it is practically a given, it should still be mentioned that these devices all feature overcurrent, overvoltage, and output short circuit protection. The table below lists some of the features of the six new series of power supplies. 


Output Voltages and Currents


Each of the new lines includes a maximum ripple noise of 100mVp-p to 150mVp-p. Notice, too, the high-efficiency range: between 72% and 88% across all devices.  


Derating Curves

CUI is confident that because each of the devices in the new series can operate at less than their maximum capacity, they will have a prolonged life. Presented below is the derating curve for the VOF-45C series.


Derating curve of VOF-45C series

Derating curve for the VOF-45C series. Image from CUI Inc


Similar derating curves in the other VOF series also speaks to an extended lifespan. 


Around the Industry

There are many manufacturers active in this competitive arena.

Mean Well offers its NFM-05 series. Input voltage range is 85VAC to 260VAC or 120VDC to 370VDC. They switch at 67kHz. There are five devices, with outputs ranging from 3.3V and 1.25A to 24V at 0.23A.

The ZWS30B series from TDK-Lambda is a series of 5 units. Power output ranges from 19.8W to 31.2W. Output voltages and currents range from 3.3V to 24V, and 6A to 1.3A, respectively.



Do you gravitate toward components designed for "green technology?" Share your experiences in the comments below.