Sponsored Content: Providing very high power DC-DC conversion for defence and other demanding applications

Introduction

The defence sector, for instance, contains many applications where all these factors count, with an added requirement for high reliability. Examples include ground based vehicular systems, targeting systems, radar, and airborne applications.

Radar applications have particularly high power requirements. One way of addressing these is to use modular DC-DC converters within power delivery networks of sufficient capacity to manage these very high power levels. To understand this approach, we can look first at the concept of modular power devices, and then at a specific high-power DC-DC converter module.

Power modules

Vicor Corporation has long experience in helping engineers overcome size, weight, cost, and power challenges, while also ensuring that their time to market is minimised. The company designs, develops, manufactures, and markets modular power components and complete power systems. Using a modular approach allows systems to be designed, configured, and tested – and then modified if necessary – far more quickly than would be possible with a ‘ground-up’ custom design. At the same time, modular configurations are far more efficient, and amenable to accurately profiling to the system’s requirements, than solutions relying on complete, bought in power supplies.

Another key aspect of Vicor’s modular architecture is that devices from their portfolio can be combined as required into complete power delivery networks that extend from an unregulated external source right to the point of load (PoL). The tasks of isolation, regulation and DC-DC conversation can be shared across these components to optimise the efficiency of an entire power network.

The DCM family is a good example of this modular approach. A DCM is an isolated, highly efficient, regulated DC-DC converter utilising high-frequency zero-voltage switching (ZVS) technology, operating from an unregulated, wide range input to generate an isolated output. DCM converters used with downstream DC-DC products support efficient power distribution, providing superior power system performance and connectivity from a variety of unregulated power sources to the point-of-load.

Vicor offers many resources to inform engineers working on DCM power designs. One example is the Application Note: ‘Achieving High-Accuracy Voltage (or Current) Regulation with the DCM™ Up to ± 1% Regulation’

Links to other Application Notes, and a Data Sheet, are given at the foot of this article.

The DCM5614 – a high-power addition to the DCM family

The requirements for a very high power radar power supply design as mentioned above could be fulfilled by a recently-announced addition to the DCM family – the DCM5614. A single DCM5614 can deliver 1300W with 96% efficiency; however, really high power applications up to just over 5kW can be achieved by operating multiple DCM5614s in arrays.

The device is implemented in a VIA package with dimensions of 5.6 x 1.4 x 0.3in (141.43 x 35.54 x 9.40mm) and achieves an unmatched power density of 451W/in3. This specification, plus a weight of just 178g, allows support of not only the radar application, but also other advanced airborne, shipboard and UAV systems where power density, weight and efficiency are critical.

With its 96% peak efficiency, the module’s heat output is significantly reduced, while the innovative planar and thermally adept VIA package enables multiple cooling strategies for enhanced thermal performance. These factors minimise heat sink requirements, which contributes to the low size and weight of DCM5614 configurations.

Figure 1: Vicor’s recently-announced DCM5614 in VIA package for defence and aerospace applications

The DCM5614 accepts 180 – 400VDC inputs, and delivers an isolated, regulated, 28V nominal Safety Extra Low Voltage (SELV) output. The low-profile module, which is available in chassis-mount and through-hole VIA package form factors, incorporates a DC-DC converter, inrush protection and optional analogue or digital communication.

The DCM offers low noise, fast transient response and high efficiency and power density. The optional secondary referenced PMBus-compatible telemetry and control interface provides access to the DCM’s internal controller configuration, fault monitoring and other telemetry functions.

The device has output overvoltage protection, as well as input undervoltage lockout and overtemperature protection. It also has integrated EMI and transient filtering. With robust packaging, it can be used in harsh environments.

Leveraging the thermal management and power benefits of VIA packaging technology, the DCM module offers flexible mechanical mounting options with low top- and bottom-side thermal resistances. When combined with downstream regulators and PoL current multipliers, the DCM enables power system architects to achieve power-system solutions with outstanding performance metrics and low total cost.

Reference materials

Engineers seeking to integrate the DCM5614 into their system design can download a number of documents to support their design effort. These include:

· DCM5614 – Datasheet

· Application Note AN:029 – Single DCM as an Isolated, Regulated DC-DC converter

· Application Note AN:030 – Parallel DCMs

· Application Note AN:035 – Achieving High-Accuracy Voltage (or Current) Regulation with the DCM™ Up to ± 1% Regulation

· Application Note AN:039 – Thermal Management for VIA™ and ChiP™ Modules