Communications Power

60A Digital POLs use new SEPIC-fed Buck Topology and Intersil Controller

CUI Inc. announced a new family of digital point of load (POL) dc-dc modules that claim performance benchmarks in efficiency, power density, and transient response to address the rapidly-rising power challenges in distributed power architectures. The NDM3ZS-60 is a non-isolated module outputting 60A in ultra-low-profile vertical and horizontal packages. The series is the first non-isolated design to incorporate CUI’s patented Solus® Power Topology which integrates a conventional buck converter into a SEPIC converter to form a SEPIC-fed buck converter; a single stage topology with one magnetic element, one control switch and two commutation switches that are optimally controlled by pulse-width modulation (pwm).

With lower voltage and current stresses in the topology coupled with an inherent gate charge extraction (GCE) process, the topology is able to reduce switching turn-on losses by 75% and switching turn-off losses by 99% on the control FET when compared to a conventional buck converter. The Solus Topology further increases total efficiency by distributing the energy delivery into multiple paths, reducing circuit conduction losses by nearly 50%.

The new topology allows the NDM3ZS-60 to hit the performance metrics such as efficiency which peaks at 91.3% for 12Vdc in to 1.0Vdc out, 50% load. Efficiency remains high up to full load at 88.5%. Transient response is also greatly improved with the SEPIC-fed buck. At 12Vdc in to 1Vdc out with a 30A load step (from 15A to 45A) and a 10A/µs slew rate, peak voltage is a mere 16mV with typical external capacitance required.

The NDM3ZS-60 is also the first released module to use Intersil's newest digital power controller, the ZL8800, incorporating a range of advanced digital features. The ZL8800's ChargeMode Control technology further enhances the module's transient response performance by responding to a transient load step in a single switching cycle. With zero compensation required, the modules autonomously balance the trade-offs between dynamic performance and system stability on a continuous basis.

As a result, designers are able to bypass the traditional practice of building-in margins to account for factors such as component ageing, manufacturing variations, and temperature, which inevitably lead to higher component cost and longer design cycles. The NDM3ZS's zero compensation feature allows the module to dynamically set optimum stability in real time as conditions change.

The NDM3ZS-60 series is available with an input range of 7.2- to 14-Vdc and a programmable output range of 0.6- to 1.5-Vdc. Additional features include voltage sequencing, voltage tracking, synchronization and phase spreading, programmable soft start and stop, as well as a host of monitoring capabilities. All features are dynamically programmable via PMBus commands or through CUI's simple, easy to use Novum ACE GUI.

The family is available in three configurations, a through-hole vertical version measuring 33.02 (L) X 8.92 (W) X 18.11 (H) mm and a horizontal version measuring 33.02 x 18.11 x 7.44 mm that is offered in surface mount or through-hole configurations. For added flexibility during the development process, the modules are footprint nested to accommodate dual layout needs in the event that design requirements change. Additionally, the NDMZ3S-60 is footprint compatible with 40A and 50A digital modules currently available from CUI and other manufacturers, providing up to a 50% increase in power density over existing solutions.

"We are very excited to announce the release of our first non-isolated POL module based on the Solus Power Topology," said Mark Adams, CUI's Senior Vice President. “Our networking customers have hit a ceiling with existing POL topologies as the challenges of powering today's advanced ICs have increased. Our NDM3ZS-60 addresses these efficiency, power density, and transient challenges head-on.”

Intersil Corporation , CUI Inc.
To Top

Join 50,000+ Power Pros

  • Keep pace with relentless innovation
  • Influence the conversation
  • Take your insights to another level

You have Successfully Subscribed!