TOR / Leaf Switch Reference Design
An illustrative TOR / Leaf switch reference design for the data center / cloud layer of the five-layer network architecture: 48 × 25G SFP28 server access ports (two SFP28 2×12 combo cages), 8 × 100G uplink ports to the Spine (two QSFP56 2×2 combo cages, fitted with QSFP28 modules), an out-of-band MGMT port and a Console port, dual hot-swap 12V supplies, and a switch SoC core powered 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 server access port topology: the TX / RX differential pairs of the switch SoC's 25G SerDes pass AC-coupling capacitors (fitted as the SerDes requires; SFP28 modules are already AC-coupled internally) to TD± / RD± of the SFP28 2×12 combo cage, with control and status lines to the SoC through I²C muxes / IO expanders; the module 3.3V is filtered by a VOOHU molded inductor, one per port. Each differential pair is drawn as a single 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 25G server access ports | Server access SFP28 2×12 integrated cage + connector ×2 | J1 J2 | SFP28 Series | WHSFP3212CF002 | VOOHU |
| 02 | A 25G server access ports | SFP28 supply filter inductors ×48 | L1 L2 L3 L4 L5 L6 L7 L8 L9 L10 L11 L12 | Molded Inductors | WHYTA0420 series | VOOHU |
| 03 | B 100G uplink | 100G uplink QSFP56 2×2 integrated cage + connector ×2 | J3 J4 | QSFP56 Series | WH81161Y22121 | VOOHU |
| 04 | B 100G uplink | QSFP supply filter inductors ×8 | L13 L14 | Molded Inductors | WHYTA0420 series | VOOHU |
| 05 | D Switch SoC | DC switch SoC (48 × 25G + 8 × 100G) | U1 | — | — | Non-VOOHU |
| 06 | D Switch SoC | DDR memory | U2 | — | — | Non-VOOHU |
| 07 | D Switch SoC | Flash | U3 | — | — | Non-VOOHU |
| 08 | C Management | MGMT RJ45 with integrated magnetics (out-of-band management port) | J5 | RJ45 with Integrated Magnetics | SYT211Q066CD2A4D | VOOHU |
| 09 | C Management | Management port Gigabit PHY | U4 | Ethernet PHY | JL2101C-NC | VOOHU |
| 10 | C Management | Console RJ45 | J6 | RJ45 Connector | WH56A11810011101 | VOOHU |
| 11 | C Management | RS-232 level shifter | U5 | — | — | Non-VOOHU |
| 12 | E 12V power | Power module interface (12V · dual hot-swap) | J7 | — | — | Non-VOOHU |
| 13 | E 12V power | Input TVS | D1 | — | — | Non-VOOHU |
| 14 | E 12V power | High-current power-line common-mode choke (EMI) | L15 | Power Line Common Mode Chokes | WHAL-1513A-101T0 | VOOHU |
| 15 | E 12V power | Synchronous buck ×2 | U6 U7 | — | — | Non-VOOHU |
| 16 | E 12V power | Molded inductors ×2 (DC-DC) | L16 L17 | Molded Inductors | WHYT0630 Series | VOOHU |
| 17 | E 12V power | Multiphase controller + DrMOS | U8 | — | — | Non-VOOHU |
| 18 | E 12V power | Combined inductors ×2 (multiphase VR) | L18 L19 | Combined Inductors | WHPBU-131308N-R11K0 | VOOHU |
Resources & downloads
Board bill of materials
Reference designators, zones, VOOHU categories, recommended parts and availability for all 18 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 TOR / leaf switch 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 tailored to your port mix (25G / 100G / 400G), cage light-pipe options or power scheme, please include it in your requirements. We reply within 24 hours on working days.
