Computer Backplanes

Definition: A backplane is a printed circuit board (PCB) with connectors that allow multiple electronic modules (e.g., CPU, memory, I/O cards) to connect and communicate. It serves as the backbone of computer systems, especially in industrial, server, and telecom applications.

Key Features

• Passive Backplane – Contains no active circuitry; relies on CPU card for processing.
• Active Backplane – Includes bus drivers, buffers, or logic.
• Hot-Swappable – Supports module replacement without powering down.
• High-Speed Traces – Designed for signal integrity at high frequencies (PCIe, SAS, etc.).

Common Types

Design Considerations

• Signal Integrity: Impedance control, length matching, crosstalk reduction.
• Power Distribution: Low impedance paths, decoupling, voltage regulation.
• Cooling: Airflow, thermal vias, connector placement.
• EMI/EMC: Shielding, grounding, filtering.

Note: Modern backplanes often support redundant power, dual-star topologies, and advanced protocols like Ethernet over backplane (e.g., 10GBASE-KR).