KSZ9031RNXIC - Gigabit Ethernet PHY Transceiver, RGMII, 48-QFN | Microchip
MPN: KSZ9031RNXIC ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.8 | $6.80 |
| 10 | $6.12 | $61.20 |
| 100 | $5.44 | $544.00 |
| 500 | $4.89 | $2,445.00 |
| 1,000 | $4.35 | $4,350.00 |
KSZ9031RNXIC Overview
A Gigabit Ethernet PHY (Physical Layer transceiver) is the analog front-end IC that connects a MAC (Media Access Controller) to a copper cable, performing PCS/PMA encoding, line driving, echo/next-cable cancellation, and link training. The KSZ9031RNXIC belongs to the Ethernet transceiver family -> network interface IC -> communication semiconductor hierarchy, and is fully compliant with IEEE 802.3 10/100/1000BASE-T specifications. Synonyms for this category include GbE PHY, Gigabit Ethernet transceiver, and triple-speed Ethernet PHY.
Key features include support for 10/100/1000 Mbps operation, RGMII interface with on-chip timing delay per RGMII v2.0 (with programming options for external delay adjustment), LinkMD cable diagnostics for cable health monitoring, Wake-on-LAN (WoL) support, and integrated termination resistors that eliminate the need for external magnetics-side resistor networks. The device operates from 1.8V/2.5V/3.3V supplies and offers automotive temperature grade options (KSZ9031RNXIA variant is AEC-Q100 qualified).
Architecturally, the KSZ9031RNXIC uses a DSP-based echo and crosstalk canceller with a 4-channel (A/B/C/D) analog front end, supporting auto-negotiation and auto-MDI/MDIX crossover. Its on-chip RGMII delay eliminates the PCB trace-length matching constraint required by RGMII v1.3 designs, simplifying layout for SoC + PHY interconnects. The 48-QFN package provides a low thermal resistance path and a small PCB footprint for space-constrained designs.
Typical applications include industrial Ethernet switches, automotive gateway ECUs, IP surveillance cameras, network routers and switches, industrial automation controllers, and any embedded system requiring a wired 10/100/1000 Mbps Ethernet uplink. The RGMII bus makes the part a natural companion to NXP i.MX, Microchip SAMA5/SAM9, and TI Sitara host processors.
When designing with this part, follow the KSZ9031RNX Hardware Design Checklist (Microchip DS00003391) for magnetics selection, RJ45 integration, and power-rail decoupling. Use a 25 MHz reference crystal or 25 MHz LVCMOS clock source, and route the RGMII traces length-matched within 50 mils if on-chip delay is disabled.
This page consolidates distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, including a same-package alternative comparison versus the KSZ9031MNX family.
Drop-in alternatives for KSZ9031RNXIC — 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 KSZ9031RNXIC (same form factor and footprint) — differing in Package, Data Rate, Operating Temperature, MAC Interface, Reference Clock.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
KSZ9031RNXIA
✅ Drop-In✓ In Stock
$3.27 / Unit
View Datasheet →KSZ9031RNXCC
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →KSZ9031RNXIC-TR
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →KSZ9031RNXCA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
KSZ9031RNXUA
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
KSZ9031RNXIC Specifications
| Product Type | Ethernet Physical Layer Transceiver (PHY) |
| Data Rate | 10/100/1000 Mbps (Triple-Speed) |
| Network Standard | IEEE 802.3 10BASE-T / 100BASE-TX / 1000BASE-T |
| Interface to MAC | RGMII (version 2.0, on-chip delay) |
| Number of Channels | 4/4 Transceiver (Full Duplex) |
| Supply Voltage | 1.8 V / 2.5 V / 3.3 V |
| Package | 48-pin QFN (7x7 mm) with Exposed Pad |
| Cable Type | CAT-5 Unshielded Twisted Pair (UTP) |
| Auto-Negotiation | Yes (IEEE 802.3u/clause 28) |
| Auto-MDI/MDIX | Yes |
| Cable Diagnostics | LinkMD TDR-based cable diagnostics |
| Wake-on-LAN | Yes (Magic Packet and wake-up frame) |
| Jumbo Frame Support | Yes (up to 9 KB) |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | MSL3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
| Reference Clock | 25 MHz crystal or LVCMOS input |
KSZ9031RNXIC Pin Configuration
| Pin 1 | VDDIO — I/O supply voltage (1.8V/2.5V/3.3V) |
| Pin 2 | TXD0 — RGMII transmit data bit 0 |
| Pin 3 | TXD1 — RGMII transmit data bit 1 |
| Pin 4 | TXD2 — RGMII transmit data bit 2 |
| Pin 5 | TXD3 — RGMII transmit data bit 3 |
| Pin 6 | TX_EN — RGMII transmit enable |
| Pin 7 | TX_CLK — RGMII transmit clock |
| Pin 8 | VDDIO — I/O supply voltage |
| Pin 9 | RXD0 — RGMII receive data bit 0 |
| Pin 10 | RXD1 — RGMII receive data bit 1 |
| Pin 11 | RXD2 — RGMII receive data bit 2 |
| Pin 12 | RXD3 — RGMII receive data bit 3 |
| Pin 13 | RX_DV/CRS_DV — RGMII receive data valid / CRS |
| Pin 14 | RX_CLK — RGMII receive clock |
| Pin 15 | MDIO — Management data I/O |
| Pin 16 | MDC — Management data clock |
| Pin 17 | INT_N — Interrupt output (active low) |
| Pin 18 | RESET_N — Hardware reset (active low) |
| Pin 19 | VDD_1V2 — Internal 1.2V LDO output (decoupling) |
| Pin 20 | GND — Digital ground |
| Pin 21 | VDDA_3V3 — Analog 3.3V supply |
| Pin 22 | BIAS_R — Bias resistor (12.1 kohm to GND) |
| Pin 23 | VDDA_1V2 — Analog 1.2V supply (from internal LDO) |
| Pin 24 | TXOP — Differential transmit output P |
| Pin 25 | TXON — Differential transmit output N |
| Pin 26 | VDDA_3V3 — Analog 3.3V supply |
| Pin 27 | RXIP — Differential receive input P |
| Pin 28 | RXIN — Differential receive input N |
| Pin 29 | VDDA_3V3 — Analog 3.3V supply |
| Pin 30 | RXVP — Differential receive (MDI pair 2) P |
| Pin 31 | RXVN — Differential receive (MDI pair 2) N |
| Pin 32 | VDDA_3V3 — Analog 3.3V supply |
| Pin 33 | TXVP — Differential transmit (MDI pair 3) P |
| Pin 34 | TXVN — Differential transmit (MDI pair 3) N |
| Pin 35 | GND — Analog ground |
| Pin 36 | LED0/PHYAD0 — LED0 output / PHY address strap LSB |
| Pin 37 | LED1/PHYAD1 — LED1 output / PHY address strap |
| Pin 38 | LED2/PHYAD2 — LED2 output / PHY address strap MSB |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | XI — 25 MHz crystal input |
| Pin 41 | XO — 25 MHz crystal output |
| Pin 42 | VDDIO — I/O supply voltage |
| Pin 43 | VDD_1V2 — Internal 1.2V LDO output (decoupling) |
| Pin 44 | CLK125_NDO — 125 MHz reference clock output |
| Pin 45 | GND — Digital ground |
| Pin 46 | VDDA_1V2 — Analog 1.2V supply |
| Pin 47 | NC — Not connected (per datasheet) |
| Pin 48 | NC — Not connected (per datasheet) |
| Pin EP | EPAD/GND — Exposed thermal pad - must be soldered to ground plane |
Typical Applications
KSZ9031RNXIC is suitable for 7 applications: Industrial Ethernet Switches and Routers, Automotive Gateway ECUs and Telematics, IP Surveillance Cameras and NVRs, Embedded Networking Modules (SoM / SBC), Server and Datacenter Management NICs, Industrial PLC and Automation Controllers, Medical Imaging and Diagnostic Equipment.
Industrial Ethernet Switches and Routers
The KSZ9031RNXIC is widely used in managed and unmanaged industrial Ethernet switches as the GbE uplink/downlink PHY. Its 1000BASE-T capability, RGMII v2.0 with on-chip delay, and LinkMD cable diagnostics enable port-density designs with remote fault detection. The 1.8V/2.5V/3.3V supply flexibility simplifies integration with both legacy 2.5V MCUs and modern 1.8V SoCs. Industrial temperature grade (-40C to +85C) supports DIN-rail and factory-floor deployments without thermal derating. The 48-QFN (7x7) footprint minimizes PCB area per port, critical in 8/16/24-port switch designs. Companion MPNs include the KSZ8999I for management plane integration and KSZ8895MQXIA for 5-port industrial switch fabrics.
Recommended
Automotive Gateway ECUs and Telematics
The automotive-grade KSZ9031RNXIA variant of this family (same 48-QFN pinout, AEC-Q100 qualified) is designed into vehicle gateway ECUs, telematics control units (TCUs), and ADAS domain controllers. 1000BASE-T over automotive-grade CAT-5 supports backhaul of sensor data from cameras and radar to the central compute. LinkMD enables predictive cable diagnostics to detect harness degradation before vehicle delivery. The RGMII v2.0 interface connects directly to NXP i.MX and Microchip SAMA5 automotive SoCs. Operating temperature supports under-hood and cabin environments. Companion MPNs include the KSZ9031RNXIA (auto grade) and NXP S32K3 for the gateway MCU host.
Recommended
IP Surveillance Cameras and NVRs
The KSZ9031RNXIC serves as the 1G Ethernet interface in IP surveillance cameras (IPCs) and network video recorders (NVRs) that stream H.265/H.264 video at 4K resolutions. The 1 Gbps link rate supports 4K@30 fps streams (15-25 Mbps) plus PTZ control plus audio on a single cable. RGMII v2.0 with on-chip delay shortens the MAC-PHY interconnect, reducing PCB complexity inside small-form-factor dome and bullet cameras. LinkMD TDR diagnostics help installers verify PoE-powered cable integrity remotely. Wake-on-LAN allows the NVR to remotely wake sleeping cameras for security patrols. The 48-QFN footprint is small enough for mini-dome housings.
Recommended
Embedded Networking Modules (SoM / SBC)
The KSZ9031RNXIC is integrated into System-on-Module (SoM) and Single Board Computer (SBC) designs that require a wired 1G Ethernet port alongside Wi-Fi. The RGMII v2.0 interface directly connects to NXP i.MX8, TI Sitara AM335x/AM437x, and Microchip SAMA7G54 SoC MACs. The 1.8V/2.5V/3.3V I/O flexibility matches modern 1.8V SoC pad voltages without level shifters. Industrial temperature grade and LinkMD cable diagnostics support industrial IoT and edge-compute applications. The 48-QFN footprint keeps the SoM baseboard area small, leaving room for additional peripherals like M.2 sockets and high-density I/O headers.
Recommended
Server and Datacenter Management NICs
The KSZ9031RNXIC provides a 1G Ethernet management port in BMC (Baseboard Management Controller) NIC designs for server and datacenter systems. While data-plane 10G/25G NICs dominate server I/O, the 1G management port is mandatory for IPMI and Redfish out-of-band access. The 48-QFN (7x7) footprint integrates into the small BMC daughter-card area. RGMII v2.0 with on-chip delay connects to the BMC SoC's MAC without external delay lines. Industrial temperature range and LinkMD cable diagnostics support remote datacenter installations. Wake-on-LAN enables scheduled server wake-on-LAN boot operations from the management console.
Recommended
Industrial PLC and Automation Controllers
The KSZ9031RNXIC enables Gigabit Ethernet connectivity in industrial PLC, PAC, and HMI controllers used in factory automation. The 1 Gbps link supports PROFINET, EtherNet/IP, and Modbus TCP real-time industrial protocols with deterministic latency. RGMII v2.0 with on-chip delay eliminates RGMII trace-length constraints inside the PLC enclosure, easing layout in IP67-rated housings. LinkMD TDR diagnostics allow remote cable health checks across long factory-floor cable runs. The industrial temperature grade (-40C to +85C) and LinkMD support rugged industrial environments. Wake-on-LAN enables the PLC to enter sleep mode and wake on network request for energy savings.
Recommended
Medical Imaging and Diagnostic Equipment
The KSZ9031RNXIC is used in medical imaging equipment (ultrasound, endoscopy, MRI interfaces) and patient monitoring systems requiring high-bandwidth network connectivity. The 1 Gbps link supports real-time image transfer from imaging modalities to PACS servers and central monitoring stations. RGMII v2.0 with on-chip delay simplifies medical-device PCB layouts that must meet IEC 60601 EMI/EMC constraints. The industrial temperature grade supports continuous operation in clinical environments. LinkMD cable diagnostics help biomedical engineers maintain hospital network infrastructure. Companion MPNs include the KSZ9031RNXIA for medical-grade applications and the EFM32GG11B520F2048IM64-B as a host MCU option.
Recommended
Recommended Products Summary
Engineering reference data for KSZ9031RNXIC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ9031RNXIA | KSZ9031RNXCC | KSZ9031RNXIC-TR | KSZ9031RNXCA | KSZ9031RNXUA |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-QFN (7x7) | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same |
| Data Rate | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps | 10/100/1000 Mbps |
| Interface | RGMII v2.0 | RGMII v2.0 | RGMII v2.0 | RGMII v2.0 | RGMII v2.0 | RGMII v2.0 |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Automotive, AEC-Q100) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +105C (Extended) |
| AEC-Q100 Qualified | No | Yes | No | No | No | Yes (auto screened) |
| LinkMD Cable Diagnostics | Yes | Yes | Yes | Yes | Yes | Yes |
| Packaging | Tray (260 units) | Tray (260 units) | Tray (260 units) | Tape & Reel (1,000 units) | Tray (260 units) | Tray (260 units) |
Key Differentiators
- Industry-standard RGMII v2.0 with on-chip delay eliminates external trace-length matching (vs DP83867IRRGZ (TI))
- LinkMD TDR-based cable diagnostics integrated for remote cable health monitoring (vs DP83848IVV (TI legacy 100M PHY))
- Automotive grade variant (KSZ9031RNXIA) drop-in compatible with same 48-QFN footprint (vs KSZ9031RNXCC (commercial grade))
Design Notes
Follow the KSZ9031RNX Hardware Design Checklist (Microchip DS00003391) for magnetics selection and RJ45 integration. Use a 1:1 turns-ratio discrete magnetics module with integrated Bob Smith termination on the cable side. Keep the MDI differential pairs (TXOP/TXON, RXIP/RXIN, RXVP/RXVN, TXVP/TXVN) matched to within 5 mils of length difference, and route them over a continuous ground plane. The 50 ohm differential impedance must be maintained from the PHY to the magnetics to avoid signal-integrity issues. The exposed pad (EP) MUST be soldered to a large ground pad for thermal dissipation and electrical reference.
Estimated: Power consumption of KSZ9031RNXIC at 1000BASE-T full duplex is approximately 500-700 mW from the 3.3V analog supply. Use a ferrite bead + 10uF + 0.1uF decoupling network on each VDDA_3V3 pin (pins 21, 26, 29, 32) to isolate analog and digital supplies. The internal 1.2V LDO (VDD_1V2 pins) requires at least 1uF low-ESR ceramic decoupling placed within 3 mm of each pin. If the host supplies 1.2V externally, the internal LDO must be disabled via the proper strap-in configuration - consult the datasheet strap-in options section.
RGMII v2.0 with on-chip delay is enabled by default, but if the host SoC also adds RGMII delay, double-delay will occur and cause link instability. Disable on-chip delay in the KSZ9031RNXIC via MDIO register 0x0C bit 0 if the host SoC applies RGMII v1.3-style PCB trace delay. Also verify PHY address strap-in pins (PHYAD0/PHYAD1/PHYAD2 on LED0/1/2) are set correctly to avoid MDIO bus address conflicts when multiple PHYs are connected. Default PHY address is 0x1F (broadcast) - set a unique address per PHY on multi-PHY designs.
RGMII traces (TXD0-3, TX_EN, TX_CLK, RXD0-3, RX_DV, RX_CLK) must be length-matched within +/- 50 mils (1.27 mm) if on-chip delay is disabled. When on-chip delay is enabled (default), TX_CLK trace length should be within +/- 100 mils (2.54 mm) of the longest TX data trace, and RX_CLK within +/- 100 mils of the longest RX data trace. Source-terminate RGMII with 22-33 ohm resistors near the PHY for signals above 100 MHz edge rate. Maintain 50 ohm single-ended impedance (100 ohm differential) on all RGMII traces.
Compliance Information
RoHS and REACH compliant per Microchip product page. AEC-Q100 NOT applicable to KSZ9031RNXIC (industrial grade) - choose KSZ9031RNXIA for AEC-Q100 automotive qualified variant. Lead-free and halogen-free per Microchip material declaration.
