1.2 kW from a 63 x 23 mm converter – and it is bi-directional
In mid-2013, Vicor described the construction of the next step in its miniaturisation of power conversion modules, without announcing product details; now, the company has issued the first such specification, for the ChiP (converter housed in pacakge) bus converter module (BCM). BCMs are fixed-ratio isolated DC/DC converters: in effect, they are “DC transformers”. The ChiP BCM takes the analogy of transformer operation one step further in that the symmetry of its internal circuitry means that it can operate bi-directionally – power flow can be in either direction.
The 63 x 23 x 7.3-mm device is a 1/8 ratio converter that will deliver 1.2 kW (1.5 kW for 10 msec) with only airflow cooling; the rating is thermally, not electrically limited and appropriate cooling will enable higher ratings, Vicor says. With a nominal input voltage of 380V and a K-factor of 1/8, the converters supply an isolated 48V distribution bus with a peak efficiency of 98%. With its input range of 260 to 410 V, the new BCM supports outputs ranging from 32.5 V to 51.25 V. BCMs are based on Vicor’s ZCS/ZVS Sine Amplitude Converter topology and operate at a 1.25 MHz switching frequency, providing fast response time and low noise operation.
ChiP BCMs may be paralleled to provide multi-kW arrays and are capable of bi-directional operation to support battery backup and renewable energy applications. Standard BCM features include under-over-voltage lockout, over-current, short circuit and over-temperature protection. ChiP BCMs incorporate digital telemetry and control features that can be configured to meet customer requirements.
The module construction uses highly-automated assembly, on large panels. Heat-dissipating components are mounted symmetrically on either side of the substrate, and magnetic components mount through the substrate, with their top and bottom surfaces exposed at the surface of the over-mould. The complete panel of assembled modules is over-moulded, then sawn as if it were a giant silicon wafer. The dimensions of the sawn converter modules are in part numbers, in mm. Exposed connections at either end of the modules receive terminations to allow normal through-hole (pins) to be added; surface mounting assembly options will be offered at a later stage. Vicor says that directly connecting the modules to the exposed-edge connections, and mounting the converters in a board cutout, is a possibility, but not one that is yet offered.
You can operate the modules with no heatsinking, or with one- or two-sided heatsinks. Advanced designs for use of the devices have already been developed that apply a pressure contact to each side of the converter, with liquid-cooling to conduct away heat. The modules use, “advanced magnetic structures integrated within high density interconnect (HDI) substrates with power semiconductors and control ASICs,” Vicor says; however, the semiconductor switches are silicon MOSFETs – the advantages come from circuit design and packaging, and not from use of exotic technologies or materials.
Vicor’s 6123 VI ChiP BCMs costs $120.00 in OEM quantities; www.vicrpower.com
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