Power management
Bus Converter Chip
Fixed-ratio DC-DC for intermediate-bus and POL distribution.
What is it?
Bus converters provide a fixed step-down ratio (e.g., 48 V → 12 V at 4:1, or 12 V → 1 V at 12:1) from a primary bus rail to an intermediate rail. Used in datacenter and telecom architectures where a high primary bus distributes power efficiently across a board, and per-load POL (Point-Of-Load) converters generate the final voltage. Bus converters trade regulation flexibility for very high efficiency at their nominal operating point.
When do you need it?
- 48 V intermediate-bus distribution to 12 V POL feeders (server racks).
- High-current low-voltage rails from a high-voltage bus (12 V → 1.0 V).
- Telecom −48 V to +12 V isolation bus.
- Industrial 24 V → 12 V conversion at higher efficiency than a regulated buck.
How to pick the right one
- Conversion ratio
- Fixed at design — 4:1, 6:1, 8:1, 12:1 common.
- Power level
- 20 W to 1 kW+ — bus converters cover a wide range, brick-format common above 200 W.
- Isolation
- Isolated bus converters provide galvanic separation; non-isolated have a tighter form factor.
- Efficiency
- Peak efficiencies of 96-98% at nominal point.
What Magnias offers
Magnias bus converter chip family targets datacenter and telecom intermediate-bus architectures. Specific part selection depends on bus voltage, conversion ratio, and isolation requirements — consult your Magnias FAE for the right variant.
Common questions
Why not just use a regulated buck?
Bus converters skip the regulation loop, so they hit 96-98% efficiency vs ~92-94% for an equivalent regulated buck. The downstream POL converters provide regulation.
Can I use a bus converter for the final rail?
Only if your load tolerates the ratio's natural output voltage range — bus converters track input without regulation. Final rails usually need a regulated POL.