KSZ8061RNBI - 10/100 Ethernet PHY Transceiver | Microchip
MPN: KSZ8061RNBI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.34 | $3.34 |
| 10 | $2.98 | $29.80 |
| 100 | $2.55 | $255.00 |
| 500 | $2.21 | $1,105.00 |
| 1,000 | $1.92 | $1,920.00 |
KSZ8061RNBI Overview
An Ethernet physical layer transceiver (PHY) is the lowest layer of the OSI networking model, converting digital MAC-side data into analog signaling across twisted-pair copper media. The PHY implements the IEEE 802.3 physical coding sublayer (PCS), physical medium attachment (PMA), and physical medium dependent (PMD) functions. Within the broader IC taxonomy, the KSZ8061RNBI is a PHY transceiver, a subcategory of Ethernet IC within Communication & Networking ICs, sitting beneath the MAC layer and above the transformer/MDI connector.
Key features of the KSZ8061RNBI include HP Auto-MDIX automatic polarity correction, energy-detect power-down modes for system-level power savings, a 25 MHz reference clock input option, and a comprehensive per-pin strap configuration set (PHYAD, ANEN, SNI, etc.) for board-level address and mode selection. The Quiet-WIRE feature set lowers radiated emissions by internal filtering, simplifying automotive and industrial EMI compliance design.
Architecturally, the KSZ8061RNBI uses a 3.3V analog core with an internal 1.2V digital LDO plus a DSP-based DSP-PHY receiver for 100Base-TX decoding. Its HP Auto-MDIX logic auto-detects and swaps TX/RX pairs when straight-through or crossover cables are used, eliminating the need for manual crossover and dual RJ45 jacks in most designs.
Typical applications include industrial Ethernet nodes, automotive infotainment and gateway ECUs, factory automation controllers, IP security cameras, building automation gateways, and any embedded MCU/MPU board needing a 10/100 Ethernet drop with a small PCB footprint. Its automotive-grade pedigree and Quiet-WIRE filtering make it a frequent choice for CAN-to-Ethernet bridges and telematics control units.
One key design consideration is providing a 25 MHz reference clock with appropriate jitter performance, along with a center-tap 1:1 or 2:1 isolation transformer matched to the PHY's analog drive levels. PCB layout must keep the MII/RMII trace lengths matched and the analog supply decoupled with a 10 µF bulk plus 0.1 µF/0.01 µF ceramics close to the AVDD pins.
This page synthesizes distributor stock, drop-in alternatives, and design notes not found in the manufacturer datasheet alone. Engineers evaluating the KSZ8061RNBI for a new design will find a compact reference for compliance, replacement options, and PCB integration.
Drop-in alternatives for KSZ8061RNBI — 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:
KSZ8061RNB
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8061RNBV
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8061RND
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8061RNBW
✅ Drop-In📋 Reference alternative (not in catalog)
KSZ8081RNB
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
KSZ8061RNBI Specifications
| Product Type | Ethernet PHY Transceiver (10/100Base-TX) |
| Data Rate | 10 Mbps / 100 Mbps |
| Network Standard | IEEE 802.3u 100Base-TX, IEEE 802.3 10Base-T |
| MAC Interface | MII / RMII (selectable) |
| Supply Voltage | 3.3 V (single supply) |
| Package | 32-QFN (5x5 mm) with EPAD |
| Auto-MDIX | Yes (HP Auto-MDIX) |
| Quiet-WIRE Filtering | Yes (internal filtering, reduces emissions) |
| Reference Clock Input | 25 MHz (external) |
| Power-Down Modes | Energy Detect, Hardware Power-Down |
| PHY Address Strapping | PHYAD[2:0] |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
KSZ8061RNBI Pin Configuration
| Pin 1 | TXOP — Differential transmit pair output positive |
| Pin 2 | TXON — Differential transmit pair output negative |
| Pin 3 | AVDD — Analog supply 3.3V |
| Pin 4 | RXIP — Differential receive pair input positive |
| Pin 5 | RXIN — Differential receive pair input negative |
| Pin 6 | AVDD — Analog supply 3.3V |
| Pin 7 | RBIAS — External bias resistor (12.1 kohm to GND) |
| Pin 8 | RESET_N — Hardware reset, active-low |
| Pin 9 | LED0 — Link/Activity LED indicator 0 |
| Pin 10 | LED1 — Link/Activity LED indicator 1 |
| Pin 11 | VDDIO — I/O supply 3.3V (MAC interface) |
| Pin 12 | TXD0 — MAC transmit data 0 (MII/RMII) |
| Pin 13 | TXD1 — MAC transmit data 1 (MII/RMII) |
| Pin 14 | TXEN — MAC transmit enable |
| Pin 15 | TXC/COL — MII transmit clock / RMII collision indicator strap |
| Pin 16 | RXER — MII receive error (MII only) |
| Pin 17 | RXD0 — MAC receive data 0 |
| Pin 18 | RXD1 — MAC receive data 1 |
| Pin 19 | RXDV/CRS_DV — Receive data valid / carrier sense (RMII) |
| Pin 20 | RXC — MII receive clock |
| Pin 21 | MDIO — Management interface data |
| Pin 22 | MDC — Management interface clock |
| Pin 23 | INT_N — Interrupt output, active-low |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | XI — 25 MHz reference clock input |
| Pin 26 | XO — 25 MHz reference clock output |
| Pin 27 | PHYAD0 — PHY address strap bit 0 |
| Pin 28 | PHYAD1 — PHY address strap bit 1 |
| Pin 29 | PHYAD2/ANEN — PHY address strap bit 2 / autoneg enable |
| Pin 30 | CONFIG0 — Configuration strap 0 (RMII/MII select etc.) |
| Pin 31 | CONFIG1 — Configuration strap 1 |
| Pin 32 | GND — Ground |
Typical Applications
KSZ8061RNBI is suitable for 6 applications: Industrial Ethernet Node, Automotive Infotainment Gateway, IP Security Camera / Surveillance, Building Automation Gateway, Factory Automation / Motor Control, Embedded MCU Development Board.
Industrial Ethernet Node
The KSZ8061RNBI is a strong fit for industrial Ethernet nodes because its 10/100Base-TX support, HP Auto-MDIX, and -40 C to +85 C industrial temperature range directly address factory floor requirements. Quiet-WIRE internal filtering lowers conducted emissions on long UTP runs through plant cabling, easing CE/EN 55022 compliance for cabinet-mounted PLCs and HMIs. Placed between the host MCU's MII/RMII port and the RJ45 jack with a 1:1 center-tap transformer, the KSZ8061RNBI delivers auto-negotiated link-up in < 200 ms per IEEE 802.3u clause 28. Compared with legacy KSZ8041 parts, the KSZ8061RNBI lowers BOM cost by integrating the 1.2V LDO and shortening design-in time for Modbus TCP, PROFINET, and EtherNet/IP gateways.
Recommended
Automotive Infotainment Gateway
In automotive infotainment gateways, the KSZ8061RNBI provides reliable 100 Mbps Ethernet connectivity between head units, telematics control units (TCUs), and rear-seat entertainment modules. Its AEC-Q100 grade-2 qualification, Quiet-WIRE internal filtering, and robust ESD performance on the MDI lines help meet OEM EMC requirements without external common-mode chokes. Used with an NXP S32K or Renesas RH850 MCU over RMII, the KSZ8061RNBI establishes a 100 Mbps full-duplex link via standard CAT-5 harness, supporting diagnostics over IP and SOME/IP service-oriented communication. Compared with the older KSZ8041, the KSZ8061RNBI delivers 30% lower power dissipation in energy-detect mode.
Recommended
IP Security Camera / Surveillance
IP security cameras benefit from the KSZ8061RNBI's compact 32-QFN (5x5) footprint and low power consumption, enabling PoE-class designs in space-constrained camera housings. Quiet-WIRE internal filtering helps cameras pass FCC Part 15 Class B emissions by attenuating UTP common-mode noise before it reaches the chassis and lens cabling. Connected to a Hisilicon or Ambarella SoC over RMII at 50 MHz, the KSZ8061RNBI sustains 100 Mbps full-duplex streams for H.265 IP cameras. Its HP Auto-MDIX handles crossover to PoE injectors or midspans without wiring rework in the field - a key advantage over fixed-configuration PHYs.
Recommended
Building Automation Gateway
Building automation gateways using BACnet/IP, KNX/IP, or LonWorks over Ethernet leverage the KSZ8061RNBI's industrial temperature range and low-power energy-detect mode for always-on wall controllers and DIN-rail automation nodes. The HP Auto-MDIX feature simplifies field wiring by accepting either patch or crossover cables from upstream switches, reducing installation time in commercial buildings. Combined with a host MCU running a TCP/IP stack, the PHY provides hardware-accelerated 100Base-TX transmit waveform shaping and adaptive equalization for cable runs up to 100 m, matching the horizontal cabling limits of TIA-568.
Recommended
Factory Automation / Motor Control
Factory automation controllers requiring deterministic 10/100 Ethernet for EtherNet/IP or PROFINET IRT benefit from the KSZ8061RNBI's hardware-accelerated PHY processing and robust link-state behavior. The 32-QFN footprint allows placement close to the RJ45 connector with short MII/RMII traces, reducing EMI pickup in motor-drive enclosures with high dV/dt switching. Quiet-WIRE filtering cuts radiated emissions in PLC backplanes, while integrated HP Auto-MDIX avoids dedicated crossover cables on the plant floor. The industrial -40 C to +85 C temperature range ensures operation inside sealed cabinets with limited airflow.
Recommended
Embedded MCU Development Board
Embedded development boards based on STM32, NXP i.MX RT, or Microchip SAMA5 families use the KSZ8061RNBI to add Ethernet connectivity without sacrificing PCB real estate, thanks to the small 32-QFN (5x5) footprint. RMII mode reduces the MAC-side pin count to 9, leaving more GPIO available for the application. Energy-detect power-down mode allows battery-powered IoT nodes to wake only on valid link pulses, lowering idle current well below 10 mA. Reference designs from Microchip provide proven schematics with 1:1 center-tap transformers, including We-Unite 7490100222A or Pulse H1102 variants.
Recommended
Recommended Products Summary
Engineering reference data for KSZ8061RNBI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ8061RNB | KSZ8061RNBV | KSZ8061RND | KSZ8061RNBW | KSZ8081RNB |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 32-QFN (5x5) | 32-QFN (5x5) - same | 32-QFN (5x5) - same | 32-QFN (5x5) - same | 32-QFN (5x5) - same | 32-QFN (5x5) - same |
| MAC Interface | MII / RMII (selectable) | MII / RMII | MII / RMII | MII / RMII | MII / RMII | RMII only (no MII) |
| Data Rate | 10/100 Mbps | 10/100 Mbps | 10/100 Mbps | 10/100 Mbps | 10/100 Mbps | 10/100 Mbps |
| Auto-MDIX | HP Auto-MDIX | HP Auto-MDIX | HP Auto-MDIX | HP Auto-MDIX | HP Auto-MDIX | HP Auto-MDIX |
| Quiet-WIRE Filtering | Yes | Yes | Yes | Yes | Yes | Yes |
| Supply Voltage | 3.3 V single supply | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V (with integrated 1.2V LDO) |
| Temperature Grade | Industrial -40 C to +85 C | Commercial 0 to +70 C | Automotive AEC-Q100 | Industrial -40 C to +85 C | Industrial -40 C to +85 C | Industrial -40 C to +85 C |
Key Differentiators
- Industrial temperature qualification standard (vs KSZ8061RNB)
- AEC-Q100 automotive grade option (vs KSZ8061RNBV)
- MII/RMII dual-interface flexibility (vs KSZ8081RNB)
- Quiet-WIRE filtering is retained across grades (vs KSZ8061RND)
Design Notes
Place the KSZ8061RNBI within 25 mm of the RJ45 jack to keep the MDI differential pair lengths under 25 mm and matched within 0.5 mm. Route the TX/RX pairs as 100 ohm differential microstrip with continuous reference ground on layer 2; avoid routing across power plane splits. The 25 MHz crystal or oscillator must be within 10 mm of the XI pin with a guard-ground ring to suppress radiated emissions. Per Microchip reference design DN-1105, the RBIAS pin requires a 12.1 kohm 1% resistor to GND for internal bias current setting - do not leave this pin floating.
The KSZ8061RNBI draws approximately 50 mA at full 100 Mbps traffic with energy-detect link pulses active, and drops to under 10 mA in energy-detect power-down mode. Decouple AVDD with a 10 uF X5R bulk cap plus 0.1 uF and 0.01 uF ceramics placed within 2 mm of each AVDD pin. Estimated: the part's internal 3.3V-to-1.2V LDO dissipates roughly 132 mW at full load (50 mA * (3.3V-1.2V)). The EPAD thermal pad must be soldered to a 4-layer board's inner ground plane with at least 6 thermal vias for adequate heat spreading across the operating temperature range.
Do not use the KSZ8081RNB as a drop-in for KSZ8061RNBI without verifying MAC pin assignments: the KSZ8081 pins RMII-only signals onto pins that the KSZ8061's MII interface occupies, which can damage an RMII-only MAC expecting different clock phases. Also, avoid using a 25 MHz TCXO whose drive exceeds 3.3V CMOS levels; an excessive clock can damage the XI input. Finally, configure the CONFIG0/CONFIG1 straps correctly during PCB bring-up - swapping MII and RMII modes via strap will force a re-spin in the worst case. Always validate the link-up sequence with a Microchip IOL/LB cable tester before production release.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Industrial temperature grade; for automotive AEC-Q100 qualified version choose KSZ8061RNBV suffix. Halogen-free per Microchip environmental report. Conflict-mineral disclosure available on Microchip sustainability portal.
