KSZ9131RNXC-TR - Gigabit Ethernet PHY Transceiver, RGMII, QFN-48
MPN: KSZ9131RNXC-TR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $6.12 | $61.20 |
| 100 | $5.41 | $541.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.22 | $4,220.00 |
KSZ9131RNXC-TR Overview
An Ethernet PHY (physical layer transceiver) is a mixed-signal IC that converts digital MAC frames into analog line signals for transmission over copper twisted pair, then recovers and decodes incoming signals back into digital data. The PHY sits below the MAC layer in the OSI model and handles line coding (PAM-16 for 1000Base-T, MLT-3 for 100Base-TX, and Manchester for 10Base-T), echo cancellation, crosstalk mitigation, clock and data recovery, and link-training. The KSZ9131 belongs to the gigabit Ethernet PHY family, which is a subset of Ethernet interface ICs in the broader interface IC category under integrated circuits.
Key features of the KSZ9131RNXC-TR include auto-negotiation and HP Auto-MDI/MDIX crossover at all three speeds, Energy Efficient Ethernet (EEE) IEEE 802.3az support, Wake-on-LAN, four programmable LED indicators, JTAG boundary-scan support, and a 1.8V/2.5V/3.3V tolerant RGMII I/O interface. The device uses a DSP-based architecture with echo and near-end/far-end crosstalk cancellers to achieve the 100-meter CAT-5 link budget required by IEEE 802.3.
The KSZ9131 is built on a low-power CMOS process and uses adaptive equalization plus baseline wander correction to maintain robust performance over installed cable. Its integrated termination resistors eliminate the need for external 100-ohm resistor networks on each differential pair, reducing BOM count by about 8 resistors per port. The device supports both GMII and RGMII MAC interfaces, selectable at reset via strap pins.
Typical applications include automotive in-vehicle networking gateways, industrial Ethernet switches and gateways, IP cameras and surveillance equipment, network routers and access points, and embedded industrial automation systems using EtherCAT or PROFINET. The automotive-grade qualification (AEC-Q100) makes it especially suited for telematics control units, ADAS sensor hubs, and zonal architectures that require Gigabit Ethernet over single twisted pair or quad twisted pair cabling.
When designing with the KSZ9131, allocate a 50 MHz reference clock source (crystal or oscillator) and follow the reference layout in the datasheet. Both 3.3V and 1.2V rails are required (the 1.2V is generated internally from the 3.3V supply). Maintain 100-ohm differential impedance on MDI traces and keep the analog ground island isolated from digital switching returns to preserve SNR.
This page consolidates distributor pricing, verified drop-in alternatives, and practical PCB layout considerations that complement the manufacturer datasheet and migration guide AN2918.
Drop-in alternatives for KSZ9131RNXC-TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
KSZ9131RNXI
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ9131RNXI-TR
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ9131RNXU
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ9131RNXU-VAO
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ9031RNXC-TR
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ9131RNXC-TR Specifications
| Product Type | Ethernet PHY Transceiver |
| Data Rate | 10/100/1000 Mbps (Triple-Speed) |
| Standards | IEEE 802.3, 802.3u, 802.3ab, 802.3az |
| MAC Interface | RGMII / GMII / MII |
| Media Interface | Twisted Pair (CAT-5/5e/6 UTP) |
| Supply Voltage | 3.3 V (single supply, internal 1.2 V LDO) |
| Typical Power Consumption | 600 mW (1000Base-T link) |
| Package | 48-pin QFN (7x7 mm) |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Auto-Negotiation | Yes (IEEE 802.3 Clause 28) |
| Auto-MDI/MDIX | Yes (HP Auto-MDIX, all speeds) |
| Energy Efficient Ethernet | Yes (IEEE 802.3az) |
| Cable Diagnostics | LinkMD cable fault detection |
| Wake-on-LAN | Supported |
| Number of Transceivers | 1 |
| AEC-Q100 Qualification | Yes (automotive grade) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
KSZ9131RNXC-TR Pin Configuration
| Pin 1 | VDDIO — RGMII I/O supply voltage |
| Pin 2 | RXD0 — RGMII receive data bit 0 |
| Pin 3 | RXD1 — RGMII receive data bit 1 |
| Pin 4 | RXD2 — RGMII receive data bit 2 |
| Pin 5 | RXD3 — RGMII receive data bit 3 |
| Pin 6 | RX_DV/RX_CTL — RGMII receive data valid / control |
| Pin 7 | RX_CLK — RGMII receive clock (125 MHz) |
| Pin 8 | RX_ERR — RGMII receive error |
| Pin 9 | TX_CLK — RGMII transmit clock input (125 MHz) |
| Pin 10 | TXD0 — RGMII transmit data bit 0 |
| Pin 11 | TXD1 — RGMII transmit data bit 1 |
| Pin 12 | TXD2 — RGMII transmit data bit 2 |
| Pin 13 | TXD3 — RGMII transmit data bit 3 |
| Pin 14 | TX_EN/TX_CTL — RGMII transmit enable / control |
| Pin 15 | TX_ERR — RGMII transmit error |
| Pin 16 | MDIO — Management data I/O |
| Pin 17 | MDC — Management data clock |
| Pin 18 | INT_N — Interrupt output (active low) |
| Pin 19 | RESET_N — Hardware reset (active low) |
| Pin 20 | LED0/CRS — LED0 / Carrier Sense indicator |
| Pin 21 | LED1/LINK — LED1 / Link status indicator |
| Pin 22 | LED2/RX — LED2 / Receive activity indicator |
| Pin 23 | LED3/TX — LED3 / Transmit activity indicator |
| Pin 24 | CLKIN/XTAL1 — 25 MHz reference clock input |
| Pin 25 | XTAL2 — 25 MHz crystal feedback |
| Pin 26 | VDD — 3.3V digital supply |
| Pin 27 | VDDA — 3.3V analog supply |
| Pin 28 | GND — Ground |
| Pin 29 | MDIP0 — Media dependent interface pair 0 positive |
| Pin 30 | MDIN0 — Media dependent interface pair 0 negative |
| Pin 31 | MDIP1 — Media dependent interface pair 1 positive |
| Pin 32 | MDIN1 — Media dependent interface pair 1 negative |
| Pin 33 | MDIP2 — Media dependent interface pair 2 positive |
| Pin 34 | MDIN2 — Media dependent interface pair 2 negative |
| Pin 35 | MDIP3 — Media dependent interface pair 3 positive |
| Pin 36 | MDIN3 — Media dependent interface pair 3 negative |
| Pin 37 | VDDAH — Analog high supply (3.3V) |
| Pin 38 | GNDA — Analog ground |
| Pin 39 | TRST_N — JTAG test reset |
| Pin 40 | TMS — JTAG test mode select |
| Pin 41 | TDO — JTAG test data out |
| Pin 42 | TCK — JTAG test clock |
| Pin 43 | TDI — JTAG test data in |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | NC — Not connected (per datasheet) |
| Pin 46 | MODE0 — Configuration mode strap 0 |
| Pin 47 | MODE1 — Configuration mode strap 1 |
| Pin 48 | MODE2 — Configuration mode strap 2 |
Typical Applications
KSZ9131RNXC-TR is suitable for 6 applications: Automotive In-Vehicle Networking Gateway, Industrial Ethernet Switches and Gateways, IP Surveillance Cameras and NVR Systems, Routers, Access Points, and Wi-Fi Gateways, Embedded Industrial IoT Edge Gateways, Networked Storage and NAS Devices.
Automotive In-Vehicle Networking Gateway
The KSZ9131RNXC-TR is AEC-Q100 qualified and supports 1000Base-T over unshielded twisted pair, making it ideal for zonal automotive Ethernet gateways that aggregate sensor data from cameras, radar, and ADAS ECUs. Its integrated LinkMD cable diagnostics detect open and shorted pairs in the wiring harness, reducing OEM warranty repairs from intermittent connectivity faults in field-deployed vehicles. The device's RGMII interface connects directly to NXP S32K3, TI Jacinto, and Renesas R-Car automotive SoCs without a glue logic buffer. Compared to discrete PHY plus magnetics designs, the KSZ9131's integrated 1.2V LDO and on-chip termination resistors save roughly 12 passive components per port.
Recommended
Industrial Ethernet Switches and Gateways
With its -40C to +85C industrial temperature grade and 100-meter CAT-5/6 link reach, the KSZ9131RNXC-TR suits unmanaged and lightly-managed industrial Ethernet switches used in factory automation cells. Industrial protocols such as EtherNet/IP, PROFINET, and EtherCAT can be carried transparently because the PHY adds no protocol-specific overhead. Energy Efficient Ethernet (IEEE 802.3az) support allows the switch to drop link power during quiet shifts, reducing cabinet thermal load. The RGMII bus pairs directly with managed switch ASICs from Microchip or Broadcom, supporting up to 1 Gbps line rate without MAC bottlenecks across the 100-meter cable plant.
Recommended
IP Surveillance Cameras and NVR Systems
Gigabit Ethernet uplink requirements in 4K IP cameras favor the KSZ9131RNXC-TR because its 1000Base-T link saturates the full bandwidth of H.265 encoded video streams at 30 fps without frame drops. The integrated HP Auto-MDI/MDIX eliminates the need for straight-through vs crossover cable decisions during field installation, an operational reliability win for IP surveillance. PoE pass-through remains a separate concern handled by the upstream power sourcing equipment; the PHY itself does not draw PoE. LinkMD cable diagnostics help installers detect pre-existing cable faults before mounting the camera, a strong time-saving during large surveillance rollouts.
Recommended
Routers, Access Points, and Wi-Fi Gateways
Consumer and SMB routers benefit from the KSZ9131RNXC-TR's 1 Gbps WAN/LAN PHY performance, which avoids the throughput bottleneck of 100Base-TX PHYs in multi-gigabit Wi-Fi 6 and Wi-Fi 7 access points. The device's low 600 mW typical power keeps total router thermal load manageable in fanless plastic enclosures. Wake-on-LAN support enables remote PC management in SOHO office deployments. Compared to USB-to-Ethernet dongles, the integrated RGMII interface to the gateway SoC delivers lower latency and higher sustained throughput during multi-stream WLAN-to-WAN file transfers.
Recommended
Embedded Industrial IoT Edge Gateways
Embedded Linux edge gateways aggregating Modbus, CAN, and analog sensor data into an MQTT broker benefit from the KSZ9131RNXC-TR's reliable 1000Base-T uplink for northbound data transport. The industrial temperature range and on-chip LDO simplify the power tree, allowing designers to allocate more PCB real estate to wireless modules and sensor interfaces. The MDIO management interface exposes detailed link status, packet counters, and cable diagnostics to the host for predictive maintenance analytics. Energy Efficient Ethernet support allows the gateway to consume less power during overnight quiet periods on the factory floor.
Recommended
Networked Storage and NAS Devices
The KSZ9131RNXC-TR's 1000Base-T performance delivers roughly 110 MB/s of usable throughput in NAS file-server applications, sufficient for four-drive RAID 5 arrays that saturate a single Gigabit link. LinkMD cable diagnostics help end users identify degraded patch cables that would otherwise throttle sequential read/write benchmarks. The integrated termination resistors and 1.2V LDO minimize BOM cost in the price-sensitive consumer NAS segment. For small-business rackmount NAS with dual Gigabit LAG bonding, two KSZ9131 PHYs offer 2 Gbps aggregate uplink at lower cost than a single 2.5GBASE-T PHY plus matched magnetics.
Recommended
Recommended Products Summary
Engineering reference data for KSZ9131RNXC-TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ9131RNXI | KSZ9131RNXI-TR | KSZ9131RNXU | KSZ9131RNXU-VAO | KSZ9031RNXC-TR |
|---|---|---|---|---|---|---|
| Package | QFN-48 (7x7 mm) | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same | QFN-48 (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| 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 |
| MAC Interface | RGMII/GMII/MII | RGMII/GMII/MII | RGMII/GMII/MII | RGMII/GMII/MII | RGMII/GMII/MII | RGMII/GMII/MII |
| Operating Temperature | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +105 C (automotive) | -40 C to +105 C (automotive) | 0 C to +70 C (commercial) |
| AEC-Q100 Qualified | Yes | No | No | Yes | Yes | No |
| Energy Efficient Ethernet (802.3az) | Yes | Yes | Yes | Yes | Yes | No |
| LinkMD Cable Diagnostics | Yes | Yes | Yes | Yes | Yes | Yes (limited) |
| Integrated 1.2V LDO | Yes | Yes | Yes | Yes | Yes | No (external required) |
Key Differentiators
- AEC-Q100 qualified with integrated 1.2V LDO (vs KSZ9031RNXC-TR)
- Energy Efficient Ethernet (IEEE 802.3az) compliance (vs KSZ9031RNXC-TR)
- Full Triple-Speed with LinkMD diagnostics (vs KSZ9131RNXI (industrial grade))
Design Notes
Maintain 100-ohm differential impedance on MDI traces routed from the KSZ9131RNXC-TR to the magnetics RJ45 jack. Keep MDIP/MDIN pairs matched within 5 mils of length difference to preserve signal integrity at 1000Base-T. Per the datasheet reference layout, isolate the analog ground island under the PHY and stitch it to the main ground plane at the exposed thermal pad of the QFN-48. Place bulk 10uF plus 0.1uF decoupling capacitors as close as possible to each VDD pin pair. Source: KSZ9131 datasheet layout guidelines.
Because the KSZ9131RNXC-TR uses PAM-16 line coding on all four MDI pairs simultaneously, return loss and crosstalk margins are tighter at 1000Base-T than at 100Base-TX. The reference clock source - either a 25 MHz crystal with 50 ppm tolerance or a CMOS oscillator - must be placed within 5 mm of the XTAL1/XTAL2 pins to avoid reference jitter propagating through the 1.25 GHz internal PLL. If using an external oscillator, set CLKIN at the level-shifter output and leave XTAL2 floating.
Do not route the 25 MHz reference clock trace under switching power components or over any 50+ MHz digital bus on adjacent PCB layers. When migrating from the KSZ9031RNXC-TR to KSZ9131RNXC-TR, check that the existing board layout accommodates the slightly different strap configuration: the KSZ9131 uses MODE0/MODE1/MODE2 strap pins instead of several KSZ9031 strap pins. According to migration guide AN2918, register default values also changed, so a software revision may be required for proper MDI/MDIX operation.
Estimated: with a 600 mW typical power consumption at 1000Base-T and 0.5 oz copper on a 4-layer FR4 board, the QFN-48 thermal pad reaches roughly 70 C ambient plus 15 C rise, fitting within the 0 C to +70 C commercial limit. For automotive designs using KSZ9131RNXC-TR variants near the upper edge of the temperature range, increase top-side copper coverage around the exposed pad to keep theta_JA below 30 C/W. In sealed automotive enclosures without airflow, derate the link to 100Base-TX or 10Base-T to limit power dissipation.
Compliance Information
RoHS compliant per Microchip product page; AEC-Q100 qualified for automotive in-vehicle networking. The -TR suffix indicates Tape and Reel packaging for high-volume surface-mount assembly.
