|June 7, 2004
Stan Michelson, Focus Communications
New Lambda NV-Power Series Provides Class-Leading Power Densities with No Compromises
SAN DIEGO, CA (June 7, 2004) - A power supply without compromise is every designer's dream. Lambda's
NV-Power is a new series of class-leading high-density and environmentally friendly AC-DC power supplies
that can give designers that no compromise solution.
"The trade-offs made in power supply designs have always been a way of life," says David Norton, vice
president of marketing for Lambda Americas. "The industry has accepted compromises in size, output
power, minimum load, acoustic noise and EMC performance. In NV-Power we have a power technology
that cuts switching losses by 50% to deliver an unparalleled efficiency of up to 90%. This technology has
enabled Lambda to create the NV-Power series without compromising any of the fundamentals."
NV-Power is based on a configurable planar transformer and employs multiple efficiency gain (MEG)
technology to achieve its class-leading efficiency for multiple-output power supplies. Lambda's approach
is to uniquely use synchronous rectifiers in a resonant topology. The patented multi-resonant-topology
(MRT) at the heart of the new design gives a 5% improvement over more traditional AC-DC power
The new MRT uses closed-loop control of the main outputs, a single conversion stage and auxiliary
channels employing high-efficiency DC-DC post regulation. NV-Power has no minimum load requirement
on any output channel. The inherent low internal voltages on the secondary side produced by Lambda's
MRT allow the use of low-voltage synchronous rectifiers with minimal losses, which improves the
The new topology uses smaller, lower-loss output inductors, along with a ferrite boost choke wound with
Litz wire. Improvements in multilayer ceramic and functional organic polymer capacitors enable the use of
simplified filter circuits without inductors, increasing efficiency and reducing size. Silicon carbide
Schottky diodes in the PFC (power factor corrected) circuit provide a further 4% improvement in
Because of these efficiency improvements, Lambda did not have to trade power for size. The first two NV-
Power units to be released, the NV-175 and the NV-350, are compatible with a 1U rack and boast class-
leading power densities of 9.36 and 6.6 watts per cubic inch, respectively.
NV-Power employs an 8-bit microcontroller to handle housekeeping routines, replacing multiple discrete
components. This reduces the part count by 50% and board space by 40%.
The open construction improves cooling, made easier by the combined benefits of the MRT and MEG
design. Reduced heat dissipation and careful thermal management eliminate heatsinks, reducing weight
and size, and low airflow volumes allow a slower fan to be used, reducing acoustical noise.
The patented soft-switching MRT design has inherently low EMI emissions, and the use of silicon carbide
Schottky diodes minimizes EMI. Moreover, the power IMS (insulated metal substrate) does not rely on
chassis conduction cooling, eliminating a potential path for noise currents to ground. This superior design
enables the NV-Power 350-watt unit to meet medical safety approvals (less than 300 microamps leakage
current) and still meet EN55022 Curve B, typically with a 6-decibel margin.
The environmentally friendly NV-Power series exceeds Energy Star guidelines for low power dissipation in
operational mode, 50% better than some competing products. It is also designed to be a totally lead-free
solution and to meet the European RoHS directive.
"Listening to our customers through Lambda's Voice of the Customer program has been key to NV-Power's
development," says Norton. "They asked for 1U height compatibility, low noise, low emissions and high
efficiency, and that's what Lambda delivered."
For more than 50 years, Lambda has been a leading provider of standard and custom power supply solutions.
The company's broad range of products power industrial, telecommunications, data communications, medical,
and test-and-measurement applications worldwide. Lambda's corporate headquarters is at 3055 Del Sol Blvd.,
San Diego, Calif., 92154; telephone 800-LAMBDA4 (toll free) or 619-575-4400; fax 619-429-1011.
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