KSZ8721SLI - 10/100 Ethernet PHY | Microchip Technology
N.º de pieza: KSZ8721SLI ✓ ActivoKSZ8721SLI Descripción general
An Ethernet physical-layer transceiver, or Ethernet PHY, converts logical digital data into electrical signaling for a physical network medium. The KSZ8721SLI belongs to the integrated-circuit hierarchy physical-layer transceiver > Ethernet interface IC > interface IC. Its 10Base-T capability supports legacy 10 Mbps copper Ethernet, while 100Base-TX/FX supports Fast Ethernet over twisted pair or optical-fiber-compatible links. The MII and RMII interfaces allow a host processor or network controller to connect through either a parallel media-independent interface or the more pin-efficient reduced media-independent interface.
Key verified features include full IEEE 802.3 operation, support for 10Base-T, 100Base-TX, and 100Base-FX physical media, and both MII and RMII host connectivity. The KSZ8721 operates its core at 2.5 V to address low-voltage and low-power requirements, while the device is described as a 3.3 V single-supply transceiver. Its 48-SSOP package provides enough pins for separate transmit, receive, management, clock, and host-interface functions.
Technically, the KSZ8721SLI consolidates a 10Base-T physical medium attachment function, a 100Base-TX/FX physical medium attachment function, and the associated host-facing digital interface into one package. MII exposes a wider parallel bus, while RMII reduces the number of host-interface signals and is commonly preferred when the connected controller supports it. The manufacturer identifies the KSZ8721 family as a 10BaseT, 100BaseTX, and FX physical-layer transceiver designed for low-power embedded networking.
Typical uses include industrial Ethernet controllers, embedded gateways, set-top equipment, printer and scanner interfaces, test equipment, and OEM network appliances. A board designer can connect the KSZ8721SLI to an Ethernet transformer or appropriate fiber interface, provide the required decoupling, and connect it to an MII- or RMII-capable controller. The choice of media interface and magnetics should be based on the required copper or fiber link distance and system compliance targets.
A critical design consideration is confirming the controller's MII or RMII timing, clock requirements, reset behavior, and supported media type against the manufacturer datasheet before layout release. Input and output supply rails should be decoupled close to the device, while the copper or fiber network path should be routed according to the selected magnetics and medium requirements. Do not infer unverified pin assignments or timing values from distributor listings alone.
This page consolidates verified manufacturer and distributor information, package details, commercially relevant sourcing links, and same-family replacement evidence. It also provides application guidance and comparison context intended to support faster component selection without treating unreported electrical parameters as verified facts.
Alternativas directas para KSZ8721SLI — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con KSZ8721SLI (mismo factor de forma y huella) — difiere en Package.
KSZ8721B-TR
✅ Sustitución directaConsulte el precio
Ver hoja de datos →KSZ8721SL-TR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
KSZ8721SLA4-TR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
KSZ8721BLI
✅ Sustitución directaConsulte el precio
Ver hoja de datos →KS8721BLI
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
KSZ8721SLI Especificaciones
| Product Type | 10/100 Ethernet physical-layer transceiver |
| Channel Count | 1 channel |
| Velocidad de datos | 10 Mbps and 100 Mbps |
| Copper Media Support | 10Base-T and 100Base-TX |
| Fiber Media Support | 100Base-FX |
| Host Interface | MII and RMII |
| IEEE Standard | IEEE 802.3 |
| Core Operating Voltage | 2.5 V |
| Supply Description | 3.3 V single power supply |
| Encapsulado | 48-SSOP |
| Tipo de montaje | Surface mount |
| Packaging | Tube |
| Link Media | 10Base-T, 100Base-TX, and 100Base-FX |
Guía de configuración de pines de KSZ8721SLI 48-ssop
Configuración de pines para KSZ8721SLI (encapsulado 48-ssop). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para KSZ8721SLI.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
KSZ8721SLI es adecuado para 6 aplicacións: Industrial Ethernet Control, Embedded Network Gateway, Printer and Scanner Interface, Test and Measurement Instrument, Set-Top and Media Device, Fiber-Backed Network Equipment.
Industrial Ethernet Control
The KSZ8721SLI fits an industrial Ethernet controller design requiring a dedicated 10/100 Ethernet PHY rather than an integrated controller-and-PHY solution. Its 10 Mbps and 100 Mbps rates, IEEE 802.3 operation, and MII or RMII host interface allow the same transceiver to serve legacy and Fast Ethernet equipment. The 2.5 V core supports low-voltage operation, while the 48-SSOP package provides the pin count required for separate media and host signals. Designers should confirm RMII timing, reference-clock requirements, reset behavior, and copper-media circuitry against the manufacturer datasheet before committing the PCB layout.
Recomendado
Embedded Network Gateway
The KSZ8721SLI is appropriate for an embedded network gateway that bridges a host processor to a 10/100 copper Ethernet port. RMII can reduce the number of host-interface signals when supported by the controller, while MII provides an alternative parallel interface. Support for 10Base-T and 100Base-TX allows the product family to address both 10 Mbps and 100 Mbps network environments, and 100Base-FX support expands the design option beyond copper. Board implementation still requires verified magnetics or fiber-interface circuitry, local supply decoupling, and timing validation between the PHY and host controller.
Recomendado
Printer and Scanner Interface
The KSZ8721SLI can provide the physical Ethernet layer in a printer, scanner, or multifunction peripheral that requires a dedicated 10/100 network connection. Its IEEE 802.3 operation and dual-rate support match conventional Fast Ethernet infrastructure, while MII and RMII give the system designer flexibility in host-controller selection. A 48-SSOP package is particularly relevant when an existing controller board already reserves that footprint. Engineers should verify reset, clock, LED, and transformer pin assignments in the official datasheet because those implementation details are not present in the verified distributor excerpts.
Recomendado
Test and Measurement Instrument
The KSZ8721SLI is suitable for test and measurement equipment that must connect to a 10/100 Ethernet management network while leaving the instrument's main processor dedicated to measurement tasks. The PHY supports both MII and RMII, giving designers a choice based on controller capability and board-space constraints. Its 10Base-T, 100Base-TX, and 100Base-FX support covers copper and fiber-oriented networking options. For reliable deployment, the design must account for network isolation, magnetics, media-side routing, supply noise, and the exact host-interface timing specified by the manufacturer datasheet.
Recomendado
Set-Top and Media Device
The KSZ8721SLI can serve as the Ethernet network interface for a set-top box, media appliance, or video-network terminal requiring 10/100 connectivity. Using RMII can limit host-bus width when the companion controller supports it, while the PHY's 100Base-TX support matches common home and business LANs. The 10Base-T function adds compatibility with slower legacy links. Integration still depends on validating the controller interface, reset sequencing, clock source, line-side magnetics, and isolation requirements. The verified product information does not provide the full timing table, so those details must be taken directly from the current Microchip documentation.
Recomendado
Fiber-Backed Network Equipment
The KSZ8721SLI's 100Base-FX capability makes it relevant to network equipment that needs an Ethernet fiber uplink in addition to copper media. In such a design, the PHY provides the physical-layer signaling path while the host controller uses MII or RMII, and an appropriate fiber interface connects the media-side signals to the optical path. This separation of digital host access and analog media signaling supports modular product designs. The integrator must select compatible fiber-interface hardware and confirm optical, biasing, and timing requirements against the manufacturer application documents; generic Ethernet PHY equivalence is not sufficient.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para KSZ8721SLI — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | KSZ8721B-TR | KSZ8721SL-TR | KSZ8721SLA4-TR | KSZ8721BLI | KS8721BLI |
|---|---|---|---|---|---|---|
| Package | 48-SSOP | 48-SSOP | 48-SSOP | 48-SSOP | 48-SSOP | 48-SSOP |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Product Type | 10/100 Ethernet physical-layer transceiver | 10/100 Ethernet physical-layer transceiver | 10/100 Ethernet physical-layer transceiver | 10/100 Ethernet physical-layer transceiver | 10/100 Ethernet physical-layer transceiver | 10/100 Ethernet physical-layer transceiver |
| Data Rates | 10 Mbps and 100 Mbps | 10 Mbps and 100 Mbps | 10 Mbps and 100 Mbps | 10 Mbps and 100 Mbps | 10 Mbps and 100 Mbps | 10 Mbps and 100 Mbps |
| Host Interfaces | MII and RMII | MII and RMII | MII and RMII | MII and RMII | MII and RMII | MII and RMII |
| Media Support | 10Base-T, 100Base-TX, and 100Base-FX | 10/100 Ethernet PHY | 10/100 Ethernet PHY | 10/100 Ethernet PHY | 10Base-T, 100Base-TX, and 100Base-FX | 10Base-T, 100Base-TX, and 100Base-FX |
Diferenciadores clave
- Supports both MII and RMII host connectivity (frente a KSZ8721B-TR)
- Combines copper and fiber-capable physical media (frente a KSZ8721SL-TR)
- Low-voltage core operation (frente a KSZ8721SLA4-TR)
- Established same-family migration path (frente a KS8721BLI)
Notas de diseño
Confirm the exact 48-SSOP pin map, MII or RMII selection, and media-side assignments from the current Microchip datasheet before routing. Keep the controller-facing clock and data traces short, provide a continuous ground reference, and place any required clock-support components close to the PHY. Because the verified excerpts do not include signal names or timing limits, do not derive the layout from the package drawing alone.
Separate the 2.5 V core rail and 3.3 V supply requirements exactly as described in the manufacturer documentation, and place bypass capacitors near the corresponding supply pins. Verify capacitor voltage ratings, effective capacitance across temperature, and the regulator's transient response. Unreported current consumption and dropout data remain unavailable in the supplied verified information and must not be estimated for thermal design.
A same-package Ethernet PHY is not automatically a functional replacement. Check MII and RMII clock direction, reference-clock requirements, reset polarity, link and status signals, LED behavior, media support, and 100Base-FX implementation before substituting KSZ8721B-TR, KSZ8721SL-TR, KSZ8721SLA4-TR, KSZ8721BLI, or KS8721BLI. Use the manufacturer migration document and current datasheets for production approval.
Route copper and fiber media interfaces using the layout and isolation guidance in the manufacturer application material, and terminate unused digital inputs according to the datasheet. Keep the Ethernet medium-side connector, magnetics or fiber interface, and PHY as a controlled high-speed signal path. Maintain grounding and shielding appropriate to the selected medium rather than treating the 48-SSOP PHY as an isolated low-speed digital component.
Información de cumplimiento
The supplied search results mention comparison pages covering RoHS and REACH but do not provide the actual compliance values. No compliance status is therefore inferred.