Teknik Özellikler
RTL8309N‑VB‑CG is a cost-effective single-chip 8+1 port 10/100Mbps Fast Ethernet switch controller developed by Realtek, integrating 8 built-in PHY transceivers, MAC units and on-chip packet memory to deliver a highly integrated compact switching solution for low-speed network devices.
Part Number Definition
RTL8309N represents the core model with 8 integrated copper PHY ports plus one independent uplink MAC port. VB denotes the standard configuration version that supports EEPROM auto-configuration and SMI register management. CG stands for QFN-64 surface mount package with exposed thermal pad, and the factory adopts tape-and-reel packaging for automated SMT production.
Core Port & Protocol Specifications
The chip comes with 8 RJ45 ports embedded with 10BASE-T/100BASE-TX PHY circuits, fully compliant with IEEE 802.3, IEEE 802.3u and IEEE 802.3x flow control standards. All ports support auto-negotiation of transmission rate and duplex mode, and each port is equipped with Auto-MDI/MDIX function to automatically correct cable pin assignment without distinguishing straight-through or crossover cables. One dedicated uplink MAC interface can be configured as MII or RMII mode to connect main processors, wireless routing SoCs or external communication modules. It adopts store-and-forward switching architecture and eliminates head-of-line blocking with intelligent switch engine. The maximum supported frame length reaches 2048 bytes, and the on-chip 2K-entry MAC address table applies 4-way associative hash algorithm to reduce address lookup conflicts and guarantee stable forwarding performance. Three independent storm suppression mechanisms are integrated to restrict broadcast and multicast packet flooding.
Management and QoS Functions
It supports port-based VLAN and 802.1Q tagged VLAN with up to 16 configurable VLAN groups, and provides four independent VLAN learning databases for flexible network segmentation. A 4-level hardware priority queuing system implements differentiated traffic scheduling, supporting port-based rate limiting and queue-based bandwidth restriction to prioritize voice and video data transmission. Additional built-in functions include per-port loopback test for equipment debugging, port mirroring for network monitoring, and broadcast/multicast storm filtering. System parameters can be loaded automatically from external EEPROM after power-up, and upper controllers can complete register configuration and status query via SMI serial management interface.
Power Supply and Clock Design
The chip works with single 3.3V power input, and internal regulators generate core voltage to simplify peripheral power circuit layout. Only one external 25MHz crystal oscillator is required as the system reference clock. Multiple low-power idle modes are available to cut power consumption when ports are disconnected or inactive. Each port reserves dedicated LED pins to indicate link status, connection speed and data activity status.
Package and Mechanical Information
Package type is 64-pin QFN quad flat no-leads package with exposed thermal pad, with an overall dimension of 9mm × 9mm. Moisture Sensitivity Level is MSL 3, and reflow soldering must be finished within 168 hours after opening the vacuum moisture-proof package. The bottom exposed pad improves thermal dissipation during continuous data transmission to enhance long-term operating stability.
Environmental and Compliance Standards
Operating ambient temperature ranges from 0 ℃ to +70 ℃. The product is fully lead-free and compliant with RoHS and REACH regulations without restricted hazardous substances. Optimized EMC design strengthens anti-interference ability to adapt to consumer networking terminals and light industrial embedded network equipment.
Tipik Uygulama Alanları
8-port desktop unmanaged and managed 10/100M mini switches and cabinet-mounted small Ethernet switches Home broadband routers, wired gateway devices and IPTV set-top box internal switching units Multi-channel IP camera monitoring equipment and small NVR host network distribution modules Smart home control gateways, embedded data acquisition terminals and multi-port network expansion boards POS payment terminals, industrial field bus conversion equipment and low-cost wired access network modules
LXB Semicon supplies original Realtek RTL8309N‑VB‑CG 8+1 port Fast Ethernet switch IC
