BCM5389KFB

Overview

The Broadcom BCM5389KFB is an eighth-generation switch-on-a-chip featuring eight Gigabit Ethernet ports with integrated SerDes. It includes nine IEEE-compliant MACs, a non-blocking 9-Gigabit switch fabric, and a 128-KB packet buffer. The device supports up to 4k unicast MAC addresses, 4k VLANs, and four 802.1p QoS queues. It operates on a low-power 0.13 µm 1.2 V CMOS core consuming less than 1.5W. The component is housed in a 256-pin FBGA package measuring 17 mm x 17 mm.

Feature Summary

• Integrates eight SGMII/SerDes interfaces for direct backplane or fiber optic connections while minimizing board layer requirements.
• Supports comprehensive traffic management including 4k VLANs, port-based rate control, and jumbo frames for high-performance server links.
• Enables fully managed applications through native Spanning Tree support and full MIB counters accessible via SPI interface.

Applications

• Standalone Gigabit Ethernet switches for SOHO environments
• Gigabit Ethernet control plane and backplane applications
• Enterprise branch office connectivity solutions

Procurement Notes

Verify the specific ordering suffix against official Broadcom documentation to confirm temperature range and packaging specifications. Ensure compatibility with required SPI programming tools for configuration. Confirm that the 256-pin FBGA footprint matches the target PCB design constraints before finalizing procurement orders.

Selection Notes

Select this component when designing cost-sensitive Gigabit switches requiring minimal external components. It is suitable for applications needing integrated SerDes to reduce trace counts. Consider its low power consumption for fanless designs. Evaluate the need for managed features like Spanning Tree if deploying in complex network topologies.

Part Context

This part belongs to Broadcom's eighth-generation SwitchC family, designed to replace multi-chip solutions. It consolidates switching fabric, memory, and media access controllers into a single die. This integration significantly reduces system complexity compared to previous generations of enterprise switching silicon.

Replacement Considerations

Consult official Broadcom substitution guides for verified alternatives. Generic cross-references are not recommended due to proprietary internal architecture differences.

FAQ

How does the BCM5389 handle high-throughput data transfers?

It supports jumbo frames, which reduce link overhead and improve efficiency for high-performance connections to corporate server farms.

What interface connects the ninth MAC to a CPU?

The ninth MAC features multiple MII interface modes, including RvMII, RGMII, and GMII, for flexible CPU connection.

Can the device operate without a CPU in unmanaged applications?

Yes, CPUs are not required to initialize or run the device in cost-sensitive unmanaged applications, providing true plug-and-play connectivity.