Two Building Blocks, Two Jobs

Vicor's brick and bus converters look similar but do different jobs. A brick converter, from the Maxi, Mini, Micro family, provides a regulated isolated output from a well-regulated input and offers the proven, second-sourceable footprint that has been a power-design staple for decades. A bus converter, the BCM, provides an isolated fixed-ratio intermediate bus that feeds non-isolated point-of-load regulators, trading regulation for very high efficiency and density. Choosing between them is the first decision in designing a power tree, and this guide explains how to make it.

The Brick Converter: Regulated and Proven

Choose a brick converter when the input is already well regulated and the load needs an isolated, regulated rail. The Maxi, Mini and Micro family uses low-noise zero-current and zero-voltage switching, supports single-wire paralleling with N+M fault tolerance, and offers output voltage adjust from 10 to 110 percent, logic enable and disable, input undervoltage lockout and output overvoltage protection. The Micro is the quarter-brick member, and models such as the V48C12C150BL2, V48C5C100BL and V48C3V3C50BL provide 12 V, 5 V and 3.3 V outputs from a 48 V input. The standard footprint and comprehensive applications manual make the family easy to design in and reuse.

When to Pick a Brick

Pick a brick when the input is a regulated bus, when you need a regulated isolated output, or when you want a proven footprint that is easy to second-source. It is the natural choice for telecom, industrial and instrument rails that run from a well-controlled bus.

The BCM Bus Converter: Fixed-Ratio and Efficient

Choose a BCM when you need an isolated intermediate bus to feed point-of-load regulators, especially in a 48 V architecture. The BCM is a Sine Amplitude Converter that runs at high frequency with a low series impedance, giving low noise, fast transient response and about 98 percent efficiency. Because the ratio is fixed, the secondary tracks the primary, and the module behaves as an efficient capacitance multiplier, letting the low-voltage bus capacitance be scaled down. The BCM6123TD1E5126T00 provides a 1/8 ratio from a 380 V input to an isolated 47.5 V bus, and the BCM6123T60E15A3T00 provides a 1/4 ratio from a 48 V bus at up to 130 A.

Choosing the Ratio

Choose the ratio so the secondary voltage sits in the range your point-of-load regulators need across the primary operating range. A 1/8 ratio suits a high-voltage primary such as 380 V, while a 1/4 ratio suits a 48 V primary that feeds a low-voltage intermediate bus. Confirm the secondary current and the isolation rating as well.

Combining Them in a Power Tree

In a hierarchical architecture the two families work together: a BCM creates the isolated intermediate bus, and brick converters and DCM modules produce the regulated rails at the point of load, with DCM modules used where the input is wide or unregulated. Partitioning the tree this way keeps each stage simple and efficient, and it lets you reuse standard modules across the design.

Getting Help

If you send your input, output, current and architecture to our FAE team, we will propose a shortlist and help partition the power tree. BeiLuo holds mainstream brick and bus converter models in regional stock and ships them with import declaration, certificate of origin and RoHS documents, so you can move from selection to production reliably.