KSZ9021GNI - Gigabit Ethernet PHY | Microchip Technology
MPN： KSZ9021GNI ✓ 啟用中KSZ9021GNI 概覽
An Ethernet physical-layer transceiver, commonly called an Ethernet PHY, converts digital data into signals suitable for twisted-pair cabling and converts received cable signals back into digital data. In the broader hierarchy, the KSZ9021GNI is an interface IC, a network interface, an Ethernet transceiver, and ultimately a semiconductor used within a wired-networking system.
The KSZ9021 supports all three major Ethernet rates used over category-5 unshielded twisted-pair cable. Its GMII interface provides the high-speed parallel connection normally required for 1000 Mbps operation, while MII support allows lower-speed or resource-constrained systems to use the same PHY family. The verified 3.135 V to 3.465 V core supply range centers around the conventional 3.3 V operating point and leaves only 165 mV of variation above nominal.
A 125 MHz clock output can be enabled after power-up or reset by pulling the CLK125_EN strap-in pin high. In GMII mode, the dedicated GTX_CLK input accepts the MAC-provided transmit clock. These clock functions allow the digital Ethernet interface to be synchronized to the PHY without requiring every system to use an additional external clock source.
The KSZ9021 is appropriate for industrial networking equipment, embedded Ethernet gateways, routers, switches, set-top equipment, and other systems that need a copper-Ethernet interface. The -40 °C to +85 °C operating range also makes it suitable for industrial equipment, although the final design must verify all voltage, timing, layout, and thermal requirements against the manufacturer datasheet.
The 8 mm by 8 mm QFN-64 package supports dense PCB layouts but requires careful exposed-pad, via, and thermal-management practices. Input and output supplies should be decoupled close to their pins, and the Ethernet magnetics, clock source, media-dependent resistor networks, and signal-routing layout must follow the reference implementation in the manufacturer datasheet.
This product page combines verified distributor pricing, availability, interface details, package information, and sourcing links with practical Ethernet design guidance. It also distinguishes verified facts from parameters that require confirmation in the full KSZ9021GN datasheet, avoiding unsupported substitution or compatibility claims.
直接替換替代品，適用於 KSZ9021GNI — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此產品無可直接替換的替代品。
申請替代品KSZ9021GNI 規格
| Product Type | Triple-speed Gigabit Ethernet PHY transceiver |
| Supported Ethernet Speeds | 10 Mbps, 100 Mbps, and 1000 Mbps |
| Maximum Data Rate | 1000 Mbps |
| Supported Physical Media | 10Base-T, 100Base-TX, and 1000Base-T |
| Cable Medium | Standard CAT-5 UTP cable |
| Digital Host Interface | GMII or MII |
| Supply Voltage Range | 3.135 V to 3.465 V |
| Nominal Core Supply | 3.3 V |
| Clock Output Frequency | 125 MHz |
| Clock Enable Control | CLK125_EN strap-in pin |
| GMII Transmit Clock Input | GTX_CLK at pin 32 |
| 工作溫度範圍 | -40 °C to +85 °C |
| 封裝 | 64-pin QFN, 8 mm x 8 mm |
| 安裝類型 | Surface mount |
| Digital Interface Supply | 1.2 V and 3.3 V |
KSZ9021GNI 64-pin qfn, 8 mm x 8 mm 腳位配置指南
KSZ9021GNI（64-pin qfn, 8 mm x 8 mm 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： KSZ9021GNI.
請參閱 資料表 以查看完整腳位配置。
典型應用
KSZ9021GNI 適用於 6 應用s: Industrial Ethernet Gateway, Gigabit Network Switch, Embedded Router and Network Appliance, Set-Top Box and Media Endpoint, Industrial Control and Data Acquisition, Automotive Ethernet Test Equipment.
Industrial Ethernet Gateway
The KSZ9021GNI fits an industrial Ethernet gateway that must support legacy 10 Mbps and 100 Mbps links as well as 1000 Mbps uplinks. Its triple-speed 10Base-T, 100Base-TX, and 1000Base-T support is particularly useful where deployed field equipment must interoperate with mixed-generation infrastructure. The -40 °C to +85 °C operating range suits industrial ambient conditions. A host controller with a compatible GMII or MII interface can connect to the PHY, while the board still requires the manufacturer-recommended magnetic interface, decoupling, media resistors, and controlled clock and strap configuration.
推薦
Gigabit Network Switch
The KSZ9021GNI can provide the copper-Ethernet physical layer for a network switch port supporting 10Base-T, 100Base-TX, and 1000Base-T. Its 1000 Mbps maximum data rate supports Gigabit Ethernet, while the GMII interface offers a conventional parallel data path to a switching or routing controller. The 3.135 V to 3.465 V core-supply range centers the design around a 3.3 V rail. Deployment requires a suitable Ethernet transformer, magnetics, controlled board layout, and a 125 MHz clock strategy consistent with the manufacturer's DS00003043A datasheet.
推薦
Embedded Router and Network Appliance
The KSZ9021GNI is suitable for embedded routers and network appliances that need a high-speed wired-Ethernet port with backward-compatible 10 Mbps and 100 Mbps operation. The device handles the physical layer over CAT-5 UTP, leaving the MAC and packet-processing functions to the host processor. Its GMII and MII choices provide design flexibility, although GMII is typically needed to support the full 1000 Mbps rate. The 64-pin 8 mm by 8 mm QFN package permits compact layouts, but exposed-pad vias and local decoupling are essential for stable thermal and electrical performance.
推薦
Set-Top Box and Media Endpoint
The KSZ9021GNI can add a wired Gigabit Ethernet connection to a set-top box, streaming appliance, or media endpoint that otherwise relies on wireless connectivity. Supporting 10Base-T, 100Base-TX, and 1000Base-T allows the endpoint to connect to home routers, access points, and managed network ports without sacrificing compatibility with older infrastructure. The host processor must support GMII or MII and provide the required 125 MHz timing solution. Designers should follow the reference magnetics and layout because the verified PHY specifications alone do not define a complete EMI-compliant Ethernet channel.
推薦
Industrial Control and Data Acquisition
The KSZ9021GNI is appropriate for industrial controllers and data-acquisition equipment that must exchange data over Ethernet while operating across extended ambient temperatures. Its -40 °C to +85 °C range and triple-speed physical-layer support allow connection to widely deployed copper networks. The MII option may suit lower-speed or lower-complexity control nodes, while GMII supports full-rate 1000 Mbps links. The design must still validate isolation, surge exposure, grounding, magnetic-component selection, and system EMC requirements, none of which are established by the PHY's basic operating-temperature and supply specifications.
推薦
Automotive Ethernet Test Equipment
The KSZ9021GNI can be evaluated for bench-top automotive Ethernet test equipment because it supports 1000Base-T alongside 100Base-TX and 10Base-T, enabling testing across several link speeds. Its -40 °C to +85 °C rating covers many industrial-lab environments, although it does not itself establish automotive qualification. The PHY requires CAT-5 UTP-compatible channel hardware and a host capable of GMII or MII signaling. Before using it near a vehicle network, engineers should verify isolation, EMC, fault injection, cable-length behavior, and applicable automotive requirements independently.
推薦
推薦產品摘要
工程參考資料，適用於 KSZ9021GNI — 比較、設計指引及合規資訊。
選型指南
主要差異化特點
- Full triple-speed copper-Ethernet support (對比LAN8742A-CZ)
- GMII and MII host-interface flexibility (對比KSZ8721B-TR)
- Documented 125 MHz clock-output function (對比LAN8742A-CZ)
設計說明
Use the manufacturer reference layout for the 64-pin QFN-64 footprint, including the exposed-pad connection, via pattern, and placement of decoupling capacitors. The supplied evidence identifies the body as 8 mm by 8 mm but does not provide land-pattern dimensions or via counts; do not infer those values from a generic QFN library drawing.
Keep the PHY, Ethernet transformer, media-dependent components, and clock source positioned according to DS00003043A. Ethernet magnetics and high-speed traces require a controlled return path, while the 125 MHz clock and GMII signals need short, symmetric routing. Review crosstalk, impedance, via stubs, and copper geometry using the manufacturer's reference layout rather than a generic Ethernet schematic.
Plan the 3.135 V to 3.465 V core supply with local bypass capacitors placed close to the appropriate pins. Verify the required digital-interface supplies, sequencing, and strap states in the full datasheet because the supplied search snippets mention 1.2 V and 3.3 V without providing every rail tolerance or decoupling value.
Do not treat similarly positioned Ethernet PHYs from other families as drop-in replacements. Pin names, strap options, clock direction, media resistors, transformer center taps, and interface voltage levels can differ even when several devices support 1000 Mbps. For KSZ9021GNI, verify all connections against DS00003043A and use the 125 MHz CLK125_EN and GTX_CLK guidance as explicit review points.
合規資訊
The supplied verified search results do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. These fields remain unknown rather than being inferred from the manufacturer or distributor listings.
