90A digital point-of-load (POL) modules for networking applications

March 18, 2015 // By Graham Prophet
CUI’s highest-current digital POL family to date is designed to address the rapidly-rising power requirements of today’s most advanced integrated circuits; NDM3Z-90 is a non-isolated module outputting 90A in ultra low-profile vertical and horizontal packages.

The series incorporates a range of advanced digital features, including programmable output range, active current sharing, voltage sequencing, voltage tracking, synchronisation and phase spreading, programmable soft start and stop, as well as monitoring capabilities.

The module is based around Intersil’s ZL8801 digital power controller; the chip’s ChargeMode Control technology means no compensation is required, allowing the modules to autonomously balance the trade-offs between dynamic performance and system stability on a continuous basis. With this feature, 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 lead to higher component cost and longer design cycles. The NDM3Z’s zero compensation feature allows the module to dynamically set optimum stability in real time as conditions change.

The 90A series has efficiency peaking at 91.4% at 12 Vdc in to 1.0 Vdc out, 50% load. Efficiency remains high up to full load at 88.7%. To address the growing sensitivity to transient load steps in today’s ICs, performance has been maximised, again with Chargemode technology which allows the module to responds to a transient load step in a single switching cycle. At 12 Vdc in to 1 Vdc out with a 45A load step (from 22.5A to 67.5A) and a 2 A/µsec slew rate, peak voltage is 28 mV with moderate external capacitance required.

The design is capable of paralleling four modules in an active current sharing manner to output up to 360A. The NDM3Z-90 series is available with an input range of 7.5~14 Vdc and a programmable output range of 0.6~1.8 Vdc. All digital features will be dynamically programmable via PMBus commands or through CUI’s Novum ACE GUI. The 90A family is available in two compact through-hole configurations, a vertical version measuring 50.80 (L) X 9.47 (W) X 19.10 (H) mm and a horizontal version measuring 50.8 x 19.1 x 9.7 mm. For added flexibility during the development process, the modules are footprint-nested to accommodate dual layout needs.