Spezifikationen
RTL8125BG‑CG is a single-port multi-gigabit Ethernet controller launched by Realtek, which integrates MAC layer, PHY transceiver, PCIe bus control unit and embedded buffer memory on a single chip, targeting PCI Express interface 2.5G wired network expansion scenarios.
Part Number Definition
RTL8125BG stands for the main model of 10/100/1000/2500BASE-T four-speed Ethernet control chip. CG refers to QFN48 leadless surface mount package with exposed thermal pad, and factory standard packaging is tape-and-reel for automated SMT mounting and mass production.
Core Protocol & Rate Specifications
It fully complies with IEEE 802.3 10BASE-T, IEEE 802.3u 100BASE-TX, IEEE 802.3ab 1000BASE-T and IEEE 802.3bz 2.5GBASE-T multi-speed Ethernet standards, supporting automatic rate negotiation between 10M, 100M, 1000M and 2500Mbps. The chip adopts advanced DSP signal processing technology, equipped with cable crossover automatic detection and correction, polarity reversal compensation, adaptive equalization, crosstalk elimination and echo cancellation algorithms, which can stably transmit 2.5G signals over existing Cat5e network cables without rewiring. The maximum supported jumbo frame length reaches 16384 bytes to improve large file transmission efficiency.
Host Interface & Core Performance
The host side adopts PCI Express 2.1 x1 bus interface, which is compatible with mainstream PCIe expansion slots of motherboards. Built-in optimized receiving and sending buffer architecture reduces CPU occupancy during high-load data transmission and lowers transmission delay and packet jitter. It supports IEEE 802.3x full-duplex flow control and half-duplex backpressure congestion control, and integrates hardware checksum offload for TCP, UDP and IPv4/IPv6 protocols to offload packet verification work from the main processor.
Expanded Function Set
It supports 802.1Q VLAN tagging, port aggregation, remote wake-on-LAN, PXE network boot and DPDK driver adaptation. The chip conforms to IEEE 802.3az energy-efficient Ethernet standard, with multiple link idle power saving modes to reduce power consumption when the network is not transmitting data. It matches Realtek Dragon network bandwidth optimization software, which can intelligently allocate transmission priority for gaming, video and file transmission services to reduce network congestion delay. Auxiliary power automatic detection function is reserved to maintain network wake-up readiness under standby power supply.
Power Supply & Peripheral Circuit
It adopts multi-group voltage input design, with external power supply providing main working voltage, and internal power management module generates core and PHY working voltages to simplify peripheral circuit layout. No complicated external peripheral devices are required except a single reference crystal oscillator and basic peripheral resistors and capacitors. Standard LED pins are configured to indicate link status, connection speed and data transmission activity.
Package & Mechanical Parameters
Package type is 48-pin QFN quad flat no-leads package with exposed bottom thermal pad. Moisture Sensitivity Level is MSL 3, and reflow soldering must be completed within 168 hours after unpacking the vacuum moisture-proof package. The exposed thermal pad effectively dissipates heat during long-term continuous high-speed transmission to avoid chip overheating and performance degradation.
Environmental & Compliance Standards
The normal operating temperature range is 0 ℃ ~ +70 ℃. The product is lead-free and fully compliant with RoHS and REACH environmental protection regulations without restricted hazardous substances. Optimized EMC electromagnetic interference suppression design ensures stable operation in desktop computers, industrial embedded equipment and server working environments.
Typische Anwendungsszenarien
PCIe x1 single-port 2.5G network adapter cards for desktop computers and workstations Onboard wired network control chip of mainstream computer motherboards and mini industrial mainboards NAS network storage equipment, small server and data backup host wired network modules Multi-channel IP camera monitoring host and video recording equipment high-speed network expansion boards Industrial control embedded systems, virtual machine hosts and low-latency gaming dedicated network interface cards
LXB Semicon supplies original Realtek RTL8125BG‑CG 2.5G multi-gigabit PCIe Ethernet controller IC
