Bcm89890 | 2025 |

The BCM89890 is a specialized Broadcom semiconductor—specifically the industry's first IEEE 802.3ch-compliant automotive multigigabit Ethernet PHY [5.7, 5.16]. It is designed for high-performance automotive networking, supporting data rates of 2.5G, 5G, and 10G over a single shielded twisted-pair cable [5.8, 5.16]. Core Technical Specifications

Standards Compliance: Fully compliant with the IEEE 802.3ch standard for automotive multigigabit Ethernet [5.7, 5.16].

Data Rates: Supports 2.5GBASE-T1, 5GBASE-T1, and 10GBASE-T1 [5.8, 5.9].

Security: Features integrated 802.1AE MACsec with 128/256-bit AES encryption to secure vehicle data communication against tampering or eavesdropping [5.6, 5.16].

Interfaces: Optimized with high-speed PCIe and XFI interfaces for seamless connection to host SoCs or switch ICs [5.16]. Key Automotive Applications

This chip serves as the backbone for next-generation vehicle architectures, particularly in the following areas:

Advanced Driver Assistance Systems (ADAS): Providing the high bandwidth required for high-resolution sensors and cameras. bcm89890

Autonomous Driving: Managing the massive data flow between sensors and central computing units.

Infotainment & Telematics: Supporting multigigabit backbones for high-definition displays and connected services. Design Advantages

Automotive Grade: Built to withstand harsh automotive environments, specifically addressing EMI/EMC requirements, noise cancellation, and low transmission jitter [5.6].

Efficiency: Designed for low power consumption and high reliability for mission-critical vehicle functions [5.6].

For more exhaustive technical documentation, you can visit the official Broadcom BCM89890 Product Page.

Broadcom BCM89890 is a specialized Ethernet transceiver (PHY) part of the BCM8989X family PCB Layout

, recognized as the world's first IEEE 802.3ch compliant multi-gigabit automotive Ethernet device. It is designed to handle high-bandwidth data demands for modern vehicles, including advanced driver-assistance systems (ADAS) and infotainment. Core Specifications Standards Compliance : Fully compliant with the IEEE 802.3ch standard, supporting speeds of 2.5G, 5G, and 10G over a single shielded twisted-pair (STP) cable. : Integrates 802.1AE MACsec

with 128/256-bit AES encryption to provide hardware-level security for in-vehicle data. Interfaces : Supports high-speed interfaces for connecting to automotive switches and SoCs. Automotive Qualification

qualified, ensuring reliability under extreme temperatures and the mechanical stresses of a vehicle environment. Key Features for Automotive Design Time-Sensitive Networking (TSN) : Includes PHY-level timestamping for

, critical for synchronizing time-critical automotive tasks. Electromagnetic Compatibility (EMC)

: Specifically engineered to meet stringent automotive requirements for low EMI/EMC and high noise cancellation. Low Power Consumption

: Designed with multiple low-power modes to reduce the overall energy footprint within the vehicle's electrical system. Common Use Cases ADAS & Autonomous Driving ADAS Sensors: Connecting ultrasonic sensors

: Moving high-resolution sensor data from cameras, LIDAR, and radar to central processing units. Infotainment & Telematics

: Supporting 4K displays and high-speed external connectivity. Smart Mobility

: Enabling the "software-defined vehicle" architecture by providing a robust, secure data backbone. Integration & Support Software Drivers : Manufacturers like

provide specialized driver packages to support the BCM89890 in automotive testing and development environments. Documentation

PCB Layout

• MII/RMII Traces: Keep these traces short and impedance-controlled (50 ohms ±10%) to the MAC (Microcontroller).
• Analog Pair: The differential pair (MDI_P, MDI_N) going to the connector must have 100-ohm differential impedance. Keep them away from clock lines and switching power supplies.
• Strap Resistors: The BCM89890 uses configuration straps at power-up. Ensure these resistors (pulling up/down specific pins) are placed within 1 cm of the device pin.

2. AEC-Q100 Qualification

Reliability is non-negotiable in automotive electronics. The BCM89890 is qualified to AEC-Q100 Grade 1 (or Grade 2 depending on the specific variant), meaning it is tested to withstand extreme temperature ranges and harsh electrical conditions found inside a vehicle.

Use Cases in Modern Vehicles

• ADAS Sensors: Connecting ultrasonic sensors, short-range radar, or interior cameras to a zone ECU. 100 Mbps is ample for raw sensor data, and the timing determinism (via 802.1AS time sync) enables sensor fusion.
• Infotainment Backchannel: Audio amplifier control, touchpad HID data, or display panel backlight control—streams that don’t need 1 Gbps but can’t tolerate CAN FD’s overhead.
• Lighting & Body Control: Smart LED matrix headlights that receive pixel-level DRL patterns, or seat controllers with memory position feedback.
• Gateway/V2X Modules: As a cost-optimized port on a central gateway for non-critical ECUs.