BRAS / Core Router Reference Design
An illustrative BRAS / core router line card reference design for the core / transport layer of the five-layer network architecture: 4 × 400G QSFP-DD line ports (1×4 ganged cage + host connectors) and 8 × 100G line ports (QSFP56 2×2 cage + connector assemblies, fitted with QSFP28 modules); the NPU connects to the switch fabric card through the backplane connector, 12V comes from the backplane, and the NPU core is supplied by a multiphase VR with combined inductors. Each position is marked with the VOOHU parts available, recommended part numbers and package pinouts.
Illustrative PCB ⇄ Schematic
Illustrative top-side view arranged by functional zone (not the actual layout). Red numbered dots mark positions VOOHU can supply. Click a component on the board, an entry in the index below or a part in the schematic to see recommended parts and package pinouts on the right.
Illustrative 400G line port topology: the NPU's line-side 8 × 50G PAM4 SerDes (400GAUI-8) transmit / receive pairs connect through AC-coupling capacitors (fitted as the SerDes requires; QSFP-DD modules are AC-coupled internally) to the QSFP-DD host connector (per QSFP-DD MSA; the cage is VOOHU WH81177004331), with management signals and I²C to the NPU; each module's Vcc / VccTx / VccRx are filtered from +3V3 by a VOOHU 0630 molded inductor, one per port (400G modules draw 4–5 A at 3.3V). The 8 pairs are drawn as one line.
Board bill of materials
Summarized by position; click any row to locate it on the board above.
| No. | Zone | Position | Ref. | VOOHU category | Recommended part | Availability |
|---|---|---|---|---|---|---|
| 01 | A 400G line ports | 400G line port QSFP-DD 1×4 cage + connector | J1 | QSFPDD Series | WH81177004331 | VOOHU |
| 02 | A 400G line ports | 400G module supply inductors ×4 | L1 L2 L3 L4 | Molded Inductors | WHYT0630 Series | VOOHU |
| 03 | B 100G line ports | 100G line port QSFP56 2×2 integrated cage + connector ×2 | J2 J3 | QSFP56 Series | WH81161Y22121 | VOOHU |
| 04 | B 100G line ports | 100G module supply inductors ×8 | L5 L6 L7 L8 | Molded Inductors | WHYTA0420 series | VOOHU |
| 05 | D NPU / TM | Network processor (NPU, with traffic management) | U1 | — | — | Non-VOOHU |
| 06 | D NPU / TM | External packet buffer (DDR / HBM) | U2 | — | — | Non-VOOHU |
| 07 | D NPU / TM | TCAM / lookup expansion | U3 | — | — | Non-VOOHU |
| 08 | C Backplane interface | High-speed backplane connector | J4 | — | — | Non-VOOHU |
| 09 | E 12V power | Backplane 12V power + hot-swap | J5 | — | — | Non-VOOHU |
| 10 | E 12V power | Input TVS | D1 | — | — | Non-VOOHU |
| 11 | E 12V power | High-current power-line common-mode choke (EMI) | L9 | Power Line Common Mode Chokes | WHAL-1513A-101T0 | VOOHU |
| 12 | E 12V power | Synchronous buck ×2 | U4 U5 | — | — | Non-VOOHU |
| 13 | E 12V power | Molded inductors ×2 (DC-DC) | L10 L11 | Molded Inductors | WHYT0630 Series | VOOHU |
| 14 | E 12V power | Multiphase controller + DrMOS | U6 | — | — | Non-VOOHU |
| 15 | E 12V power | Combined inductors ×2 (multiphase VR) | L12 L13 | Combined Inductors | WHPBU-131308N-R11K0 | VOOHU |
Resources & downloads
Board bill of materials
Reference designators, zones, VOOHU categories, recommended parts and availability for all 15 positions. Opens directly in Excel.
Datasheet collection
Datasheet PDFs for the VOOHU parts recommended on this board.
Design files & footprint library
Schematic, PCB, and VOOHU part footprints and 3D models.
Coming soonRequest the BRAS / core router reference design full package
Includes the full-board position list, datasheets for the recommended VOOHU parts and position-by-position selection notes. For selection advice on your line card port plan (400G / 100G port counts and layout), cage cooling options or power scheme, describe them in your requirements. We reply within 24 hours on business days.
