KSZ9021RN Gigabit Ethernet Transceiver | Microchip
MPN： KSZ9021RN ✓ 啟用中KSZ9021RN 概覽
An Ethernet PHY, or physical-layer transceiver, converts digital data from a network controller into electrical signals for copper cabling and converts received signals back into digital data. The KSZ9021 belongs to the Ethernet transceiver hierarchy alongside network-interface controllers, magnetics, connectors, and CAT5e/CAT6 cabling. It handles the physical layer while the linked controller manages higher-level frame processing.
The device supports automatic negotiation of 10, 100, or 1000 Mbps operation. Its RGMII interface is associated with the KSZ9021R configuration, while the datasheet describes 3.3 V/2.5 V-tolerant digital I/O and configurable timing delays on both transmit and receive paths. Loopback modes support verification of analog and digital paths, and Micrel LinkMD TDR-based cable diagnostics can identify faulty copper cables.
The KSZ9021RN is the smaller package option within the KSZ9021 family. The manufacturer offers the same transceiver in a 64-pin lead-free E-LQFP as KSZ9021RL, a 64-pin lead-free QFN as KSZ9021GN, and a 128-pin lead-free PQFP as KSZ9021GQ. Only the 48-pin QFN ordering code is mechanically interchangeable with an existing KSZ9021RN footprint; the other family packages require PCB changes.
Typical uses include industrial Ethernet equipment, network controllers, routers, switches, IP cameras, and embedded systems requiring a copper Ethernet physical layer. The RGMII timing controls are especially useful when signal-integrity or propagation-delay differences between controller and PHY require board-level compensation.
Design the 48-QFN layout according to the manufacturer footprint and datasheet guidance, paying particular attention to exposed-pad thermal dissipation, copper-return paths, magnetics isolation, and RGMII trace matching. Confirm device programming, strap configuration, clock requirements, cable support, and operating-temperature grade before releasing a production design.
This page consolidates verified manufacturer and distributor information, separates genuine drop-in choices from package variants, and adds application, sourcing, and design guidance beyond a basic distributor listing. Values not explicitly supplied by the verified sources remain explicitly marked as needed rather than estimated.
直接替換替代品，適用於 KSZ9021RN — 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。
此系列的變體
與下列產品可直接替換的同系列型號： KSZ9021RN （相同外形與佔位） — 差異在於 Auto-Negotiation, Operating Temperature, Package, RoHS Status.
此產品無可直接替換的替代品。
申請替代品KSZ9021RN 規格
| Product Type | Single-chip Gigabit Ethernet transceiver with RGMII support |
| Supported Data Rates | 10/100/1000 Mbps |
| Ethernet Compliance | IEEE 802.3 |
| Host Interface | RGMII for the KSZ9021R configuration |
| 供應電壓 | 3.3 V |
| Interface I/O Tolerance | 3.3 V/2.5 V tolerant |
| Timing Control | Programmable transmit and receive delays |
| Auto-Negotiation | Automatic selection of the highest supported link-up speed |
| Cable Diagnostics | Micrel LinkMD TDR-based faulty-copper-cable identification |
| Test Features | Remote and local loopback for analog and digital path verification |
| 封裝 | 48-pin QFN, 7 x 7 mm |
| Package Family | QFN surface-mount family |
| 工作溫度 | 0°C to +70°C |
| Lead-Free Status | Lead-free package |
| RoHS 狀態 | RoHS compliant |
| 安裝類型 | Surface mount |
| Internal Register Interface | Extended registers |
| Unit Price | $6.5948 at LCSC as of 2026-10-22 |
KSZ9021RN qfn surface-mount family 腳位配置指南
KSZ9021RN（qfn surface-mount family 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： KSZ9021RN.
請參閱 資料表 以查看完整腳位配置。
典型應用
KSZ9021RN 適用於 6 應用s: Industrial Ethernet Controller Interface, Gigabit Network Switch Port, Networked Camera and Security Equipment, Embedded Linux Gateway, Test and Measurement Ethernet Instrument, Router and Gateway Equipment.
Industrial Ethernet Controller Interface
The KSZ9021RN fits a 1 Gbit copper-Ethernet port when the host controller uses RGMII. Its 10/100/1000 Mbps support and automatic link-speed negotiation allow the same physical layer to serve legacy 100 Mb/s links and Gigabit connections. Programmable transmit and receive delays provide adjustment for controller-to-PHY timing differences, while LinkMD TDR diagnostics help identify faulty cabling. The 0°C to +70°C range makes it best suited to controlled indoor equipment unless the surrounding system has separate environmental qualification.
推薦
Gigabit Network Switch Port
KSZ9021RN can provide the copper physical layer for a 1 Gbit switch port connected through an RGMII-based switching controller. IEEE 802.3 support, auto-negotiation, and 3.3 V operation align with conventional network-port architectures, while configurable delays help tune edge timing at the board level. Careful separation between PHY and magnetics, short high-speed traces, and verified thermal management of the 48-QFN exposed pad are essential for stable 1 Gbit operation.
推薦
Networked Camera and Security Equipment
KSZ9021RN supports the physical layer for IP cameras and surveillance equipment that need a reliable 10/100/1000 Mbps copper connection. Auto-negotiation accommodates different switch-port speeds, and loopback functions assist production verification of analog and digital paths. Cable diagnostics can narrow failures to interconnect problems, reducing board-level troubleshooting time. Designers should pair the PHY with suitable network magnetics, controlled-impedance routing, grounding, and surge-protection components appropriate to the installation environment.
推薦
Embedded Linux Gateway
A KSZ9021RN-based port suits embedded Linux gateways requiring a conventional Gigabit Ethernet MAC connection rather than a hardwired protocol controller. The RGMII interface offers a standardized high-speed host path, and programmable delays provide an extra variable for board timing optimization. Deployment quality depends on correct strap and register setup, validated magnetics selection, stable 3.3 V supply, Linux driver support, and preproduction testing across 10, 100, and 1000 Mb/s links and cable lengths.
推薦
Test and Measurement Ethernet Instrument
KSZ9021RN is applicable to bench instruments that communicate over standard copper Ethernet at 10, 100, or 1000 Mbps. Its remote and local loopback modes support verification of transmit, receive, analog, and digital paths during production. LinkMD TDR diagnostics can help distinguish cabling faults from board failures, shortening test time. For laboratory equipment, designers should still verify low-EMI behavior, isolation requirements, enclosure grounding, and long-term cable compatibility under the intended environmental conditions.
推薦
Router and Gateway Equipment
KSZ9021RN can implement a high-speed WAN or LAN copper port in a router or gateway with an RGMII controller. IEEE 802.3 operation, auto-negotiation, and 1 Gbit support fit contemporary network equipment, while programmable path delays reduce sensitivity to board-level timing differences. Production design should include verified magnetics, controlled-impedance layout, robust thermal coupling under the QFN exposed pad, and automated link tests at all supported rates before environmental qualification.
推薦
推薦產品摘要
工程參考資料，適用於 KSZ9021RN — 比較、設計指引及合規資訊。
選型指南
設計說明
Follow the exact KSZ9021RN 48-QFN footprint and exposed-pad instructions in the manufacturer datasheet; no pin table or pad geometry was included in the verified excerpts, so these details were not inferred. Keep RGMII traces short and continuous, maintain a solid ground reference beneath high-speed nets, avoid stubs, and place PHY support components close to their associated pins. Validate the final layer stack and timing with the intended magnetics and controller rather than copying a generic Ethernet layout.
Use the KSZ9021RN programmable transmit and receive delays as board-level compensation, not as permission for uncontrolled routing. Establish nominal MAC-to-PHY timing first, characterize the assembled PCB and magnetics, then adjust delays with margin at 10 and 100 Mb/s as well as 1 Gb/s. Source-end, device, and channel timing must be evaluated together because a setting that works on one board or controller may fail after component, temperature, or cable changes.
Do not treat KSZ9021RL, KSZ9021GN, KSZ9021GQ, or KSZ9031RNX as drop-in alternatives merely because they belong to related Ethernet families. The former parts use different package pin counts and footprints, while Microchip documents a different register-access architecture for KSZ9031RNX. Confirm the exact 48-QFN ordering code, programming procedure, operating-temperature range, and PCB revision before substituting any MPN.
合規資訊
The verified Microchip datasheet result describes the KSZ9021 family packaging as RoHS compliant and identifies the RL, GN, and GQ package options as lead-free; the RN is described as the 48-pin QFN ordering option. No exact RN declaration for REACH, halogen-free status, conflict minerals, or automotive qualification was supplied.
