FRAMINGHAM, Mass. — Artesyn
Technologies has introduced a new series of compact 250 watt ac-dc power supplies that are ideal front-end
conversion solutions for systems with distributed power architectures. The new NLP250 series power supplies provide
a choice of 12 V, 24 V or 48 V outputs to simplify system integration, backed by extensive control and monitoring
features to satisfy a wide variety of dc supply requirements. For distributed power applications, the 24 V and 48 V
models are suitable for feeding on-board isolated brick or intermediate bus converters, while the 12 V model can be
used to directly power boards fitted with multiple non-isolated point-of-load (POL) dc-dc converters. In addition to
the main output channel, each power supply also provides an auxiliary ‘always-on’ 5 Vdc output for
applications that require standby operation, as well as a 12 V output for powering fans.
The 12 V and 24 V models are also available with full medical approvals, for
applications such as patient monitoring systems and other portable equipment used in medical wards and surgical
NLP250 series ac-dc power supplies employ a rugged U-channel construction, combined
with highly integrated layout and packaging techniques, to realize a small form factor, high functionality unit
capable of delivering high levels of useable power. Measuring just 4 x 7 inches, with a profile of only 1.5 inches,
the supplies have a power density of 6.0 watts per cubic inch. The main output channel can deliver up to 175 watts
continuously under free air convection conditions, rising to 250 watts with 200 LFM forced air cooling. The power
supplies accommodate a wide ambient operating temperature range of 0 ˚C to 70 ˚C, maintaining
full rated output up to 50 ˚C.
All NLP250 series power supplies feature a universal input that
accepts any voltage in the range 85 to 264 Vac at any frequency from 47 to 63 Hz, enabling them to be used
in equipment destined for any part of the world. Active power factor correction minimizes input harmonic current
distortion and ensures compliance with the international EN61000-3-2 standard. The power supplies employ the latest
high frequency switch-mode technology to maximize conversion efficiency, typically achieving 84% at full load with a
115 Vac input, and 86% with a 230 Vac input.
Primarily intended as low- to medium-power
front-end units for distributed power systems, the small physical size and high functionality of NLP250 series ac-dc
power supplies makes them especially suitable for use in information technology equipment (ITE) and light industrial
systems. Built-in control and monitoring features include ‘ac power fail’ and ‘dc OK’ output
signals and a remote on/off input, and the supplies are comprehensively protected against overcurrent, overvoltage
and overtemperature conditions.
NLP250 series 12 V, 24 V and 48 V power supplies provide
maximum main channel output currents of 21 A, 10.5 A and 5.25 A respectively. Active
‘democratic’ current sharing, enabling multiple units to be connected in parallel for higher current
applications, is available on select models. These models also incorporate internal Or-ing diodes fitted to the main
output, for fault-tolerant and N+1 redundancy applications. All NLP250 series power supplies have a high surge
current capability – they can deliver up to 130% of their rated steady state current for 500 ms –
enabling them to start up into capacitive loads or to power electromechanical devices such as relays, actuators,
motors and print-head solenoids.
main output channel voltage of each supply can be adjusted 5% either side of nominal via an internal trim
potentiometer, and regulation is maintained to within ±2% for all line and load conditions. Differential
remote sense facilities are provided to compensate for up to 0.2 V drop between the main channel output
terminals and the load. The auxiliary 5 Vdc output is regulated to within ±5% and can deliver up to
1.0 A; it is primarily intended for powering ‘standby’ circuitry that needs to remain on for most
of the time, such as power-up/down sequencers, and is unaffected by the on/off status of the main output channel.
The auxiliary 12 V fan output can deliver up to 0.3 A and is present whenever the main output channel is
All NLP250 series ac-dc power supplies comply with the rigorous EN55022-B and FCC part 15 Level B EMC
standards for conducted noise and meet all applicable immunity standards, including EN61000-4-2, -3, -4, -5 and -6
levels 3. The power supplies carry UL/cUL60950-1 and EN60950-1 VDE safety approvals, and the medical versions are
also approved to UL/cUL2601-1 and VDE EN60601-1. The standard industrial versions of the supplies have isolation
ratings of 3000 Vac input/output and 1500 Vac input/chassis, while the medical versions have higher
4000 Vac input/output and 2000 Vac input/chassis ratings. The latter also have a very low safety ground
leakage figure of 140 µA, compared to 1 mA for the industrial versions, and are equipped with fuses
in both live and neutral inputs.
Sample quantities of Artesyn’s NLP250 series power supplies,
including models with medical approvals, are available for immediate delivery. Standard lead-time for both types is
stock to 8-12 weeks. Pricing starts at US$127.00 for the ITE/industrial models and US$140.00 for the medical models,
in quantities of 250.