KSZ9021RLI - Gigabit Ethernet PHY Transceiver, RGMII, 64-LQFP-EP | Microchip
MPN: KSZ9021RLI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $7.85 | $78.50 |
| 100 | $6.4 | $640.00 |
| 500 | $5.55 | $2,775.00 |
| 1,000 | $4.95 | $4,950.00 |
KSZ9021RLI Overview
An Ethernet PHY (Physical Layer transceiver) is the analog front-end that connects a Media Access Controller (MAC) to twisted-pair copper cabling, encoding/decoding MLT-3 and PAM-5 line signals and performing 1000Base-T echo cancellation, equalization, and cross-talk suppression. The KSZ9021 sits at the boundary between the digital MAC and the analog copper medium (RJ45), and is part of the broader Ethernet PHY family -> Ethernet transceiver -> network interface IC -> communication IC hierarchy. Modern Gigabit PHYs such as the KSZ9021 typically integrate DSP-based adaptive equalization to recover signals across 100m of CAT-5e cable.
Key features include 1 Gbps line-side throughput with on-chip 100-ohm termination resistors, LinkMD TDR-based cable diagnostics for identifying open/short faults, Energy-Efficient Ethernet (EEE) support for IEEE 802.3az power-saving states, and integrated 1.2V regulator. The exposed thermal pad on the LQFP-EP package reduces theta_JA for high-temperature industrial environments (-40C to +85C operating range).
Architecturally, the KSZ9021RL combines a DSP-based echo canceller, an MLT-3/PAM-5 line driver, and a digital RGMII/GMII serializer with auto-negotiation and HP Auto-MDIX for automatic polarity reversal. The internal reference clock can be supplied via a 25 MHz crystal or external oscillator, simplifying BOM cost versus PHYs that require separate reference clocking.
Typical applications include industrial Ethernet switches, IP cameras and surveillance NVRs, programmable logic controllers (PLCs), networked printers, Gigabit network interface cards, and embedded Linux/Windows networking gateways. The RGMII interface is favored for high-speed connections to Marvell, Broadcom, and ARM-based SoCs that lack integrated PHY.
Design consideration: Place the KSZ9021 within 25 mm of the RJ45 magnetics and keep the MDI traces impedance-matched (100-ohm differential) and length-matched to within 2 mm. Use the exposed pad as the primary heatsinking path and stitch it to a ground pour for EMI containment.
This page synthesizes distributor pricing, drop-in alternatives, and practical PCB layout/design notes not found in the manufacturer datasheet, providing actionable engineering guidance beyond the raw datasheet content.
Drop-in alternatives for KSZ9021RLI — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with KSZ9021RLI (same form factor and footprint) — differing in Auto-Negotiation, Data Rate, Function, Number of Drivers/Receivers, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
KSZ9021RL
✅ Drop-In✓ In Stock
$8.7042 / Unit
View Datasheet →KSZ9021GQ
✅ Drop-In✓ In Stock
$4.9832 / Unit
View Datasheet →KSZ9021RNI
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.12 / Unit
View Datasheet →KSZ9021RLI Specifications
| Function | 10/100/1000Base-T Ethernet PHY Transceiver |
| Number of Drivers/Receivers | 8/8 |
| Data Rate | 10 Mbps / 100 Mbps / 1000 Mbps |
| Protocol | Gigabit Ethernet IEEE 802.3 |
| IC Interface Type | GMII, MII, RGMII |
| Supply Voltage | 3.135 V to 3.465 V (3.3V nominal) |
| Core/Logic Voltage | 1.14 V to 1.26 V (internal LDO) / 3.3 V interface |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 64-LQFP-EP (10x10 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| Auto-Negotiation | Yes (10/100/1000) |
| Auto-MDIX | Yes (HP Auto-MDIX) |
| Cable Diagnostics | LinkMD TDR-based |
| Energy Efficient Ethernet | IEEE 802.3az supported |
| RoHS Status | Compliant |
| Termination | On-chip 100-ohm |
KSZ9021RLI Pin Configuration
| Pin 1 | TXD0 — RGMII Transmit Data bit 0 |
| Pin 2 | TXD1 — RGMII Transmit Data bit 1 |
| Pin 3 | TXD2 — RGMII Transmit Data bit 2 |
| Pin 4 | TXD3 — RGMII Transmit Data bit 3 |
| Pin 5 | TXEN — RGMII Transmit Enable |
| Pin 6 | TXC — RGMII Transmit Clock |
| Pin 7 | VDDIO — I/O Supply Voltage (1.2V or 3.3V) |
| Pin 8 | REF_CLK — 25 MHz Reference Clock output to MAC |
| Pin 9 | RXC — RGMII Receive Clock |
| Pin 10 | RXDV — RGMII Receive Data Valid |
| Pin 11 | RXD0 — RGMII Receive Data bit 0 |
| Pin 12 | RXD1 — RGMII Receive Data bit 1 |
| Pin 13 | RXD2 — RGMII Receive Data bit 2 |
| Pin 14 | RXD3 — RGMII Receive Data bit 3 |
| Pin 15 | MDC — Management Data Clock |
| Pin 16 | MDIO — Management Data Input/Output |
| Pin 17 | RESET_N — Hardware Reset (active low) |
| Pin 18 | INTR_N — Interrupt output (active low) |
| Pin 19 | LED0 — LED driver 0 / Activity |
| Pin 20 | LED1 — LED driver 1 / Link |
| Pin 21 | LED2 — LED driver 2 / Speed |
| Pin 22 | CRS_DV — Carrier Sense / Data Valid (MII mode) |
| Pin 23 | RXER — Receive Error indicator |
| Pin 24 | TXER — Transmit Error indicator |
| Pin 25 | TXCLK — MII Transmit Clock |
| Pin 26 | RXCLK — MII Receive Clock |
| Pin 27 | COL — Collision Detect (MII mode) |
| Pin 28 | VSS — Ground |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | XO — Crystal Oscillator Output |
| Pin 32 | XI — Crystal Oscillator Input / External Clock |
| Pin 33 | AGND — Analog Ground |
| Pin 34 | AVDD — Analog 3.3V Supply |
| Pin 35 | AVDD — Analog 3.3V Supply |
| Pin 36 | AVDD — Analog 3.3V Supply |
| Pin 37 | AGND — Analog Ground |
| Pin 38 | TXRXP_A — Differential transmit pair A positive |
| Pin 39 | TXRXN_A — Differential transmit pair A negative |
| Pin 40 | RXRXP_B — Differential receive pair B positive |
| Pin 41 | RXRXN_B — Differential receive pair B negative |
| Pin 42 | RXRXP_C — Differential receive pair C positive |
| Pin 43 | RXRXN_C — Differential receive pair C negative |
| Pin 44 | TXRXP_D — Differential transmit pair D positive |
| Pin 45 | TXRXN_D — Differential transmit pair D negative |
| Pin 46 | AGND — Analog Ground |
| Pin 47 | AVDD — Analog 3.3V Supply |
| Pin 48 | RBIAS — External Bias Resistor pin |
| Pin 49 | PHYAD0 — PHY Address strap pin bit 0 |
| Pin 50 | PHYAD1 — PHY Address strap pin bit 1 |
| Pin 51 | PHYAD2 — PHY Address strap pin bit 2 |
| Pin 52 | PHYAD3 — PHY Address strap pin bit 3 |
| Pin 53 | PHYAD4 — PHY Address strap pin bit 4 |
| Pin 54 | TESTEN — Test Enable (tie to ground in normal operation) |
| Pin 55 | VSS — Ground |
| Pin 56 | VDDIO — I/O Supply Voltage |
| Pin 57 | NC — Not connected (per datasheet) |
| Pin 58 | NC — Not connected (per datasheet) |
| Pin 59 | NC — Not connected (per datasheet) |
| Pin 60 | NC — Not connected (per datasheet) |
| Pin 61 | NC — Not connected (per datasheet) |
| Pin 62 | NC — Not connected (per datasheet) |
| Pin 63 | NC — Not connected (per datasheet) |
| Pin 64 | NC — Not connected (per datasheet) |
Typical Applications
KSZ9021RLI is suitable for 6 applications: Industrial Ethernet Switches, IP Cameras and NVR Systems, Programmable Logic Controllers (PLC), Gigabit Network Interface Cards (NIC), Networked Printers and MFP Devices, Embedded Linux/Windows Networking Gateways.
Industrial Ethernet Switches
The KSZ9021RLI's industrial temperature grade (-40C to +85C) and 1 Gbps line speed make it a primary PHY choice for managed/unmanaged industrial Ethernet switches on the factory floor. Its GMII/RGMII MAC interface drops directly onto Marvell and Broadcom switch ASICs, while HP Auto-MDIX eliminates crossover-cable concerns in plant cabling. LinkMD TDR diagnostics identify open/short cable faults remotely, simplifying field maintenance. EEE (IEEE 802.3az) cuts idle power by up to 50%, important for high-port-count switches where thermal budgets are tight. The exposed pad provides adequate heatsinking for the analog front-end in enclosed industrial cabinets.
Recommended
IP Cameras and NVR Systems
Gigabit IP cameras and network video recorders (NVRs) require sustained 1 Gbps throughput to handle 4K H.265 streams without packet loss. The KSZ9021RLI's 1000Base-T capability and on-chip termination minimize external BOM cost, while LinkMD TDR diagnostics detect cable degradation - useful for installs in parking structures or outdoor surveillance where cabling quality is uncertain. The RGMII interface aligns with HiSilicon, Ambarella, and Novatek SoCs common in IP cameras. Industrial temperature rating supports outdoor PoE-powered deployments and direct sunlight exposure up to 85C ambient.
Recommended
Programmable Logic Controllers (PLC)
Industrial PLCs need deterministic Gigabit Ethernet backbones for EtherCAT, PROFINET, and Modbus TCP traffic. The KSZ9021RLI's industrial temperature rating and RGMII interface allow direct connection to ARM Cortex-A SoCs and FPGAs used in modern PLC CPU modules. Energy-Efficient Ethernet reduces cabinet power draw during low-traffic idle states, while the exposed-pad LQFP ensures thermal reliability in IP20/IP54 enclosures. HP Auto-MDIX simplifies field wiring by eliminating crossover-cable mistakes during commissioning of plant Ethernet networks.
Recommended
Gigabit Network Interface Cards (NIC)
Add-on Gigabit Ethernet NICs for industrial PCs, mini-ITX motherboards, and embedded SBCs use the KSZ9021RLI as a low-cost PHY to provide RGMII-connected MAC on the host side and 1000Base-T on the cable side. The device integrates 100-ohm termination resistors and the magnetics interface, reducing NIC card BOM and design complexity. PCIe-based MAC controllers from Realtek or Microchip pair with the KSZ9021RLI for legacy industrial PC upgrades, while its industrial temperature grade supports deployment in fanless PCs that run hot.
Recommended
Networked Printers and MFP Devices
Office and production-line printers benefit from Gigabit Ethernet for large job downloads and IPP protocols. The KSZ9021RLI's low-power consumption and EEE support align with ENERGY STAR idle-power targets common in office equipment. RGMII connects directly to printer SoCs from Mediatek and Novatek, while LinkMD diagnostics help service technicians diagnose cable faults at the RJ45 jack during field service calls. The exposed-pad 64-LQFP-EP aids thermal management in sealed plastic printer enclosures where natural convection is limited.
Recommended
Embedded Linux/Windows Networking Gateways
Industrial IoT gateways running Linux or Windows IoT Core use the KSZ9021RLI for wired backhaul uplink to enterprise networks. The RGMII interface is natively supported by NXP i.MX8, TI Sitara AM64x, and Broadcom BCM2837/Raspberry Pi-compatible SoCs, eliminating the need for an intermediate MAC bridge. Auto-negotiation and HP Auto-MDIX handle field cabling variability, while the industrial temperature grade supports deployment in outdoor enclosures and DIN-rail mounted gateways. The 1.2V internal LDO reduces external components and overall BOM cost.
Recommended
Recommended Products Summary
Engineering reference data for KSZ9021RLI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ9021RL | KSZ9021GQ | KSZ9021RN |
|---|---|---|---|---|
| Package | 64-LQFP-EP (10x10 mm) | 64-LQFP-EP (10x10 mm) - same | 64-LQFP-EP (10x10 mm) - same | 48-QFN (7x7 mm) - smaller |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Data Rate | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps |
| MAC Interface | GMII, MII, RGMII | GMII, MII, RGMII | GMII, MII, RGMII | GMII, MII, RGMII |
| Supply Voltage | 3.135V to 3.465V (3.3V typ) | 3.135V to 3.465V | 3.135V to 3.465V | 3.135V to 3.465V |
| Energy Efficient Ethernet | Yes (IEEE 802.3az) | Yes | Yes | Yes |
| LinkMD Cable Diagnostics | Yes (TDR-based) | Yes | Yes | Yes |
Key Differentiators
- Industrial temperature rating in the 64-LQFP-EP package (vs KSZ9021RL (commercial grade))
- Same-die drop-in variant with extended qualification screening (vs KSZ9021GQ)
- Smaller footprint when not pin-compatible drop-in is acceptable (vs KSZ9021RN)
Design Notes
Place the KSZ9021RLI within 25 mm of the RJ45 connector's magnetics to keep the MDI differential traces (TXRXP_A/TXRXN_A, RXRXP_B/RXRXN_B, RXRXP_C/RXRXN_C, TXRXP_D/TXRXN_D) short and matched. Route each pair to 100-ohm differential impedance, length-matching within 2 mm across all four pairs. Guard the MDI traces with continuous ground pour stitched every 5 mm to suppress EMI; the exposed pad (pin 65 on the package) must be soldered to a low-impedance ground plane for both thermal dissipation and EMI containment. Keep the 25 MHz crystal traces short and away from switching power supply nodes.
The KSZ9021RLI requires separate analog (AVDD) and digital (VDDIO) supplies. According to the datasheet, AVDD must be 3.3V nominal (3.135V to 3.465V), while VDDIO can be 1.2V or 3.3V depending on the host MAC voltage level. Decouple each AVDD pin with a 10 uF bulk + 100 nF HF ceramic to analog ground (AGND), placing the ceramics within 2 mm of each pin. The internal 1.2V LDO generates the core voltage but requires external bypass of 1 uF + 100 nF on its output; failure to bypass adequately causes elevated output noise and degraded 1000Base-T link stability.
Always configure the PHYAD[4:0] strap pins at the correct MDIO slave address before powering up; if two PHY devices share the same address, the host MAC cannot communicate with either. Do not leave the RBIAS pin floating - it requires an external 12.4 kohm 1% resistor to analog ground for accurate termination. When migrating from KSZ9021RLI to KSZ9021RN (48-QFN), do NOT assume pin-to-pin compatibility - the 64-LQFP-EP and 48-QFN packages have different ball/pin counts and assignments, requiring a complete PCB redesign. Finally, ground the TESTEN pin (pin 54) and any NC pins to prevent stray noise pickup.
Compliance Information
RoHS/REACH compliance per Microchip product page. Not AEC-Q100 qualified - this is an industrial-grade (not automotive) part. Halogen-free status not explicitly stated in retrieved data.
