VSC8641XJF - 1-Port GbE Copper PHY with RGMII/GMII | Microchip
N.º da peça: VSC8641XJF ✗ Fim de vidaVSC8641XJF Visão geral
A PHY (Physical Layer transceiver) is the lowest layer of an Ethernet link. It converts parallel digital MAC data into differential copper signalling for twisted-pair cabling, and recovers clock and data from the received analogue waveform. In the OSI-style hierarchy, a PHY sits below the data link layer and the MAC controller: MAC -> PHY -> transformer -> twisted pair. Because the VSC8641XJF integrates the analogue front end, line drivers, comparators, clock recovery and digital interface logic on one die, it removes the discrete magnetics interface complexity that would otherwise dominate a copper Ethernet port design.
Key features of the VSC8641XJF include a 1/1 driver-receiver configuration in a PHY transceiver, support for all three copper speeds (10, 100 and 1000 Mb/s) on a single port, full-duplex operation, and both RGMII and GMII MAC-side interfaces so it can attach to a wide range of switching silicon. The device runs from 2.5 V and 3.3 V supplies and is offered in an 88-VFQFN exposed-pad package suitable for surface-mount assembly and copper-heat-spreader land patterns.
Architecturally the device is a low-power, highly integrated Gigabit PHY originally developed by Vitesse Semiconductor and now maintained by Microchip Technology. It is intended to pair with a separate MAC or switch ASIC over RGMII, which keeps the digital interconnect short and low-cost relative to integrating a full switch fabric on the same die. The exposed pad in the package provides the thermal path for the analogue and clocking sections during continuous 1000BASE-T operation.
Typical end applications include standalone copper-to-fibre media converters, industrial and telecom access equipment, IP cameras and surveillance front ends, set-top and access gateways, and single-port Ethernet links embedded in test and measurement instruments. Any design that needs one deterministic, low-latency 1000BASE-T copper port with a selectable MAC interface benefits from the device.
When designing around the VSC8641XJF, remember that the exposed pad must be tied to the ground plane and the MAC interface timing must be budgeted against the RGMII/GMII specification, since the PHY does not include the packet buffer that an integrated switch would provide. Because the device is listed by the manufacturer as not recommended for new designs, confirm lifecycle and support status before committing to a long production program.
This page consolidates manufacturer and distributor documentation, parameter comparisons and drop-in alternatives into one engineering reference, adding design notes, thermal and layout guidance and parameter-by-parameter comparison tables that are not available on a single distributor listing.
Alternativas drop-in para VSC8641XJF — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com VSC8641XJF (mesmo formato e footprint).
VSC8641XKO
✅ Drop-InConsulte o preço
Ver ficha técnica →VSC8641XKO-03
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
VSC8641XJF Especificações
| Device Type | Ethernet PHY Transceiver |
| Number of Drivers/Receivers | 1/1 |
| Supported Speeds | 10/100/1000BASE-T |
| MAC-Side Interface | RGMII and GMII |
| Tensão de alimentação | 2.5 V, 3.3 V |
| Encapsulamento / Caixa | 88-VFQFN with exposed pad (10 x 10 mm) |
| Tipo de montagem | Surface Mount |
| Operating Mode | Full duplex |
| Port Count | 1 copper port |
| Line Coding / Medium | Copper twisted pair, 10/100/1000BASE-T |
| Original Manufacturer | Vitesse Semiconductor Corporation |
| Current Maintainer | Microchip Technology |
| Status do ciclo de vida | Not Recommended for new designs |
| Lead-Free / Pb-Free | Pb-Free (per distributor listing) |
| Datasheet Document Size | 2 pages, approximately 635 kB |
| Maximum Link Rate | 1000 Mb/s |
Guia de Configuração de Pinos do VSC8641XJF 88-vfqfn with exposed pad (10 x 10 mm)
Configuração de pinos para VSC8641XJF (pacote 88-vfqfn with exposed pad (10 x 10 mm)). A numeração dos pinos, funções e diagramas de conexão estão definidos no datasheet do fabricante. Consulte-o para o footprint exato e diretrizes de soldagem.
Nenhum dado detalhado de pinagem disponível para VSC8641XJF.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
VSC8641XJF é adequado para 6 aplicaçãos: Copper-to-Fibre Media Converter, Industrial Ethernet Switch Line Card, IP Camera and Surveillance Front End, Telecom Access Equipment, Test and Measurement Front Panel, Industrial IoT Gateway and Controller.
Copper-to-Fibre Media Converter
The VSC8641XJF suits single-port media converters because it terminates one 1000BASE-T copper link on the analogue side and hands the recovered data to the host controller over RGMII or GMII. Its 1/1 driver-receiver configuration maps directly onto a one-port bridge design, and the exposed-pad QFN footprint gives the thermal path needed inside a compact metal enclosure. Expected: sustained 1000 Mb/s full-duplex throughput with a MAC-side interface that avoids adding a separate buffer ASIC. Design note: the exposed pad must be tied to ground with dense thermal vias, and the 2.5 V and 3.3 V rails each need their own local bulk and high-frequency decoupling close to the supply pins.
Recomendado
Industrial Ethernet Switch Line Card
In an industrial switch line card, the VSC8641XJF provides the copper-facing PHY for a port while the switch ASIC handles frame forwarding, giving a clean division between analogue signalling and packet processing. The availability of both RGMII and GMII on the device lets the same PHY silicon serve legacy 8-bit controllers as well as modern reduced-gmii switch silicon. The full-duplex 10/100/1000BASE-T support allows auto-negotiation across mixed-speed enterprise and industrial cabling. Design note: budget RGMII trace matching and a dedicated 50 MHz or 125 MHz clock source, and check the exposed-pad thermal budget against the enclosure ambient before the design is frozen.
Recomendado
IP Camera and Surveillance Front End
IP camera and NVR front ends need one reliable copper port per channel, which is exactly the single-port topology the VSC8641XJF implements with a 1/1 driver-receiver configuration. Placing the PHY on the camera board keeps the RGMII link to the video processor short and removes the discrete analogue receive chain from the design. Expected: 1000BASE-T full-duplex link to the network with the RGMII side delivering packet data to the image pipeline. Design note: in sealed camera housings the exposed pad is the only thermal escape path, so tie it to a solid ground pour and verify copper weight for 1000BASE-T continuous operation.
Recomendado
Telecom Access Equipment
Access and aggregation equipment often mixes copper service ports with optical uplinks, and the VSC8641XJF handles the copper termination while a separate MAC or switch ASIC handles framing. Because the device was designed for low-power, low-cost Gigabit Ethernet in access-class hardware, it fits well in CPE and line-card form factors where each board supports a limited number of copper ports. The 2.5 V and 3.3 V supply requirement is compatible with typical telecom board rails. Design note: isolate the PHY clocks from switching regulators on the same board and keep the RGMII bus away from the power inductors to protect the recovered clock from jitter.
Recomendado
Test and Measurement Front Panel
Instrument front panels typically expose a single Ethernet management or trigger port, and the VSC8641XJF provides that port with a MAC-side interface that can be simple or fully featured depending on the embedded controller. Its low component count suits instruments where board area is constrained but a full switch is unnecessary. Expected: a stable 1000BASE-T management link with no external magnetics interface design required beyond the standard network transformer. Design note: the analogue section is sensitive to layout, so keep the magnetics and differential pairs away from noisy digital return currents and provide a clean, low-impedance ground reference under the exposed pad.
Recomendado
Industrial IoT Gateway and Controller
IoT gateways aggregate a small number of copper links toward an uplink, and the VSC8641XJF provides the wired-side port with a 1/1 driver-receiver configuration that keeps the design compact and low power. Pairing the PHY with a microcontroller or application processor over GMII or RGMII gives a straightforward single-port ethernet segment without a switch ASIC. Expected: full-duplex 1000 Mb/s with auto-negotiated support for 10 and 100 Mb/s links to legacy field equipment. Design note: the part is listed as not recommended for new designs, so for long-life gateway programs either stock the required volume early or evaluate a currently recommended single-port PHY on the same RGMII footprint.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para VSC8641XJF — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | VSC8641XKO | VSC8641XKO-03 |
|---|---|---|---|
| Brand | Microchip Technology (originally Vitesse Semiconductor) | Microchip Technology | Microchip Technology |
| Package | 88-VFQFN with exposed pad (10 x 10 mm) | 88-VFQFN with exposed pad - confirm footprint in manufacturer datasheet | 88-VFQFN with exposed pad - confirm footprint in manufacturer datasheet |
| Device Type | Ethernet PHY Transceiver | Ethernet PHY Transceiver | Ethernet PHY Transceiver |
| Number of Drivers/Receivers | 1/1 | 1/1 | 1/1 |
| Supported Speeds | 10/100/1000BASE-T | 10/100/1000BASE-T | 10/100/1000BASE-T |
| MAC Interface | RGMII and GMII | RGMII and GMII | RGMII and GMII |
| Supply Voltage | 2.5 V, 3.3 V | 2.5 V, 3.3 V | 2.5 V, 3.3 V |
| Operating Mode | Full Duplex | Full Duplex | Full Duplex |
| Lifecycle Status | Not Recommended for new designs | Not Recommended for new designs | Not Recommended for new designs |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount |
| Port Count | 1 copper port | 1 copper port | 1 copper port |
Principais diferenciais
- Single-port 1000BASE-T PHY with both RGMII and GMII on the same die (vs VSC8641XKO)
- Documented equivalent-product path for supply risk mitigation (vs VSC8641XKO-03)
- 1/1 driver-receiver configuration suited to single-port designs (vs Multi-port GbE switch devices such as KSZ9897RTXI)
- Exposed-pad thermal path in a surface-mount package (vs VSC8641XKO)
Notas de projeto
Estimated: the 88-VFQFN package has no dedicated thermal rating published in the distributor listings, so treat the exposed pad as the primary thermal path. For a design dissipating roughly 1 W in the PHY, with a typical exposed-pad construction on a 4-layer board, the effective theta_JA lands in the range of 30 to 40 C/W, giving a junction rise of about 30 C to 40 C above ambient. Do not use this estimate as a specification; pull theta_JA from the manufacturer package information and confirm with a thermal simulation of the actual stack-up, copper pour area and via array before release.
The 88-lead QFN requires careful escape routing: plan the fanout on a fine-pitch land pattern with 0.5 mm or finer pitch, route the RGMII or GMII bus as a length-matched group on a single layer where possible, and keep the magnetics-side differential pairs to the PHY as short and symmetric as the layout allows. Place the input and output bypass capacitors on the same layer as the device pins and no more than a few millimetres away, and stitch the exposed pad to the ground plane with a dense via field directly under the pad rather than a single via.
Two mistakes dominate designs around this part. First, the VSC8641XJF and its package variants are listed as not recommended for new designs, so a long-life production program should either commit to a secured quantity or migrate to a currently recommended single-port copper PHY. Second, the device is a PHY, not a MAC or switch: it needs an external MAC or switch ASIC, a stable clock source for the RGMII/GMII interface, and the standard network magnetics on the copper side. Omitting the magnetics or the MAC clock source produces link-up failures that look like PHY defects.
Gigabit copper signalling is spread-spectrum and the recovered clock is sensitive to supply ripple and radiated noise. Separate the 2.5 V and 3.3 V rails' local decoupling from the switching regulator outputs, keep the exposed-pad ground return current path short, and avoid routing the RGMII/GMII clock traces beneath or parallel to the switching inductor footprints. If link-up proves intermittent, measure the recovered clock for jitter and the supply rails for ripple before replacing the PHY.
The device requires both a 2.5 V and a 3.3 V rail to be present and properly sequenced around reset. Ensure each rail has bulk capacitance near the supply pins and that the MAC-side supply ramp does not precede the PHY's internal reference settling, otherwise the port may report link-down or unstable status until the first reset pulse. Follow the reset sequence shown in the manufacturer datasheet rather than relying on power-on defaults, and verify the reset pin polarity before committing the board layout.
Informações de conformidade
Distributor listings describe the VSC8641XJF as Pb-Free. RoHS, REACH, halogen-free and conflict-minerals declarations are not stated in the available listings and must be confirmed from the Microchip product page materials declaration before use in regulated designs. The device is an Ethernet PHY transceiver for copper links, so AEC-Q100 automotive qualification does not apply.
