SpaceVPX-BP-SS
3U SpaceVPX Single-String Backplane
SpaceVPX VITA 78 5 Slots All Four SpaceVPX Planes
DESCRIPTION
The SpaceVPX-BP-SS is a 3U SpaceVPX (VITA 78) single-string backplane supporting one System Controller (SLT3-CTL) and up to four Payload slots (SLT3-PAY). All four SpaceVPX electrical planes — utility (P0), control (P1), data (P2), and expansion (P3) — are fully implemented, providing SpaceWire control-plane star topology, SERDES Fat Pipe and Thin Pipe data-plane routing, PCIe Gen2 ×4 expansion-plane connectivity, and centralised power distribution. The backplane is fabricated on a space-qualified high-speed PCB laminate and is designed to be mechanically and electrically compatible with all CAVU SpaceVPX modules.
KEY FEATURES
- 5-Slot Configuration1× SLT3-CTL + 4× SLT3-PAY — compatible with all CAVU SpaceVPX modules:
- SpaceWire Star Topology: System Controller distributes 4 SpaceWire links radially to each payload slot
- PCIe Gen2 ×4: CTL expansion plane to payload slots; PCIe switch card supported
- Power Distribution: 5 V, 12 V, 3.3 V rails to all slots via P0/J0 utility plane
- 4-Slot Variant: Compact 4-slot configuration (1× CTL + 3× PAY) also available
- VITA-46 Connectors: MULTIGIG RT2 per slot — all SpaceVPX signal planes and power distributed
- All 4 SpaceVPX Planes: Utility, Control (SpaceWire), Data (SERDES), Expansion (PCIe) — fully implemented
- SERDES Fat / Thin Pipe: Per-slot SERDES routing per VITA 78 Fat Pipe and Thin Pipe profiles
- PSU-Polar-3U Ready: Direct mating with CAVU PSU-Polar-3U power supply card
- Conduction-Cooled: Compatible with VITA 48.2 wedge-lock cards — no airflow required
- SpaceVPX-BP-DS Upgrade: System can be upgraded to dual-string by substituting SpaceVPX-BP-DS
SLOT PROFILES & PLANE CONNECTIVITY
- Total slots: 5 (1× SLT3-CTL + 4× SLT3-PAY); 4-slot variant available
- System Controller slot: SLT3-CTL — slot 1; provides SpaceWire star hub and PCIe root
- Payload slots: SLT3-PAY — slots 2–5; full Fat Pipe / Thin Pipe and SpaceWire endpoints
- Utility plane (P0): 5 V, 12 V, 3.3 V power rails; SpaceWire system management; reset; clock
- Control plane (P1): SpaceWire — ECSS-E-ST-50-12C star topology from SLT3-CTL to each PAY slot
- Data plane (P2): SERDES Fat Pipe (up to 10 lanes) and Thin Pipe between CTL and PAY slots
- Expansion plane (P3): PCIe Gen2 ×4 from SLT3-CTL; supports PCIe switch payload card fan-out
- SERDES per PAY slot: Up to 10 lanes Fat Pipe + 4 lanes Thin Pipe per VITA 78 profile
- Clock distribution: 100 MHz SpaceVPX reference clock to all slots from backplane oscillator
ELECTRICAL SPECIFICATIONS
- Input voltage: 5 V, 12 V, 3.3 V via P0/J0 utility connector (from PSU-Polar-3U or external)
- Max slot current (5V): 5 A per slot (25 A total backplane capacity at 5 V)
- Max slot current (12V): 2 A per slot (10 A total backplane capacity at 12 V)
- SpaceWire links: 4× 100 Mbps ECSS SpaceWire links (SLT3-CTL to each SLT3-PAY)
- PCIe bandwidth: PCIe Gen2 ×4 — up to 16 Gbps bidirectional (expansion plane)
- SERDES data plane: Per VITA 78: up to 12.7 Gbps per lane; up to 10 lanes per slot
MECHANICAL
- Form factor: 3U SpaceVPX (VITA 78) Backplane
- Dimensions (5-slot): ~290 × 180 mm
- Dimensions (4-slot): ~235 × 180 mm
- Connector per slot VITA-46 MULTIGIG RT2
- Operating temp.: −40°C to +85°C
- Mass (5-slot): ∼350 g (PCB + connectors)
- Mounting: 4× M3 threaded standoffs to chassis
COMPATIBLE SYSTEMS
- OBC-Polar VPX: SLT3-CTL — System Controller
- OBC-64 VPX: SLT3-CTL — high-performance controller
- PolarStore-2S/4S: SLT3-PAY — SATA storage
- PolarStore-2N/4N: SLT3-PAY — NVMe storage
- SpaceUM-Polar: SLT3-SWI — utility switching
- PSU-Polar-3U: Power input to backplane P0
