onsemi NCN26010XMNTBG

Overview

NCN26010XMNTBG from onsemi is an IEEE 802.3cg-compliant 10BASE-T1S MAC+PHY IC controller integrating Media Access Controller, PLCA Reconciliation Sublayer, and physical layer transceiver for industrial multi-drop Ethernet over single unshielded twisted pair. It operates at 10 Mb/s half-duplex, supports Open Alliance MACPHY SPI interface, and delivers fast startup (<100 ms) with enhanced noise immunity mode.

For engineers reviewing the NCN26010XMNTBG datasheet, pinout, applications, or equivalent options, key selection factors include PLCA arbitration support for ≥8-node shared-medium operation, dual configurable digital I/Os (DIO0/DIO1), 4 mm × 4 mm QFN-32 package, and 3.3 V supply with 2.5 V I/O compatibility.

Technical Context

The NCN26010XMNTBG implements a full 10BASE-T1S PHY with integrated CSMA/CD MAC and PLCA Reconciliation Sublayer (RS), enabling collision-free deterministic communication on shared UTP media. Its PMA includes differential line drivers (LINEP/LINEN), VDRVN regulator output, and energy detection threshold (250 mV typical) for robust operation in noisy industrial environments.

It communicates via Open Alliance–compliant SPI slave interface (up to 25 MHz at 3.3 V), supports both store-and-forward and cut-through frame handling, and features dedicated registers for PLCA configuration (MMS4), PHY control (MMS0/3), and MAC filtering (MMS1). Boot mode is selected via DIO0 strapping pin.

Key Specifications

Pinout & Package

NCN26010XMNTBG uses a 4 mm × 4 mm QFN-32 package (Case 485GH) with exposed thermal pad (EP). Pin pitch is 0.4 mm. The device requires decoupling capacitors on VDD (2.2 µF), VDDIO (100 nF), and VDRVN (2.2 µF), plus external 25 MHz crystal (100 ppm, CL = 12 pF) connected to XI/XO.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10BASE-T1S MACPHY applications.

Compared with MAX22503EASA+ and DP83TD510EIRHBR, NCN26010XMNTBG uniquely integrates PLCA arbitration hardware, reducing host MCU processing load by offloading round-robin scheduling and collision avoidance - essential for resource-constrained edge nodes in time-critical industrial networks.

Availability

NCN26010XMNTBG is available at Aetrix Electronics and suitable for industrial automation, sensor interfacing, and building control applications requiring stable component supply, long-term lifecycle support, and automotive-grade reliability.

Supply support for NCN26010XMNTBG includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCN26010XMNTBG belongs to onsemi's Industrial Ethernet product line, designed specifically to enable robust, low-cost, multi-drop 10BASE-T1S networks in harsh electromagnetic environments.

FAQ

What is the primary function of the NCN26010XMNTBG in an industrial Ethernet system?

The NCN26010XMNTBG serves as a fully integrated 10BASE-T1S MAC+PHY controller that handles physical layer signaling, media access control, and PLCA arbitration on a single chip. It enables deterministic, low-latency communication over unshielded twisted pair in multi-drop topologies - eliminating the need for separate MAC and PHY ICs and reducing host MCU firmware complexity. NCN26010XMNTBG is engineered for seamless integration into industrial edge nodes where space, power, and real-time performance are constrained.

Does the NCN26010XMNTBG support both PLCA and CSMA/CD modes simultaneously?

No, the NCN26010XMNTBG supports either PLCA or CSMA/CD operation, selected via configuration registers (e.g., PLCAENABLE bit in MMS4 address 0xCA01). When PLCA is enabled, the integrated Reconciliation Sublayer enforces round-robin transmit opportunities and disables CSMA/CD backoff logic. In CSMA/CD mode, PLCA functionality is inactive. NCN26010XMNTBG does not operate both protocols concurrently - the choice is mutually exclusive and determined at runtime through SPI register writes.

Can the NCN26010XMNTBG operate with a 25 MHz external clock instead of a crystal?

Yes, the NCN26010XMNTBG accepts a 25 MHz LVCMOS reference clock applied to the XI pin, with XO left floating. The device supports ±100 ppm frequency accuracy for both crystal and external clock sources, meeting IEEE 802.3cg timing requirements. When using an external clock, no load capacitors (CXI/CXO) are required, simplifying layout and reducing BOM count. NCN26010XMNTBG's internal oscillator circuitry automatically adapts to the selected clock source without firmware changes.

What is the purpose of the DIO0 and DIO1 pins on the NCN26010XMNTBG?

DIO0 and DIO1 are dual-purpose general-purpose I/O pins configurable as programmable LVCMOS outputs with selectable pull-up/pull-down resistors. Each can drive low-current LEDs directly (with external current-limiting resistors) or interface with discrete logic, status indicators, or auxiliary sensors. DIO0 also serves as a strapping pin to select NORMAL or ISOLATED boot mode. NCN26010XMNTBG's register map (MMS12 address 0x0012) allows dynamic reconfiguration of these pins post-boot, enabling flexible system-level signaling without additional GPIO expanders.

How does the NCN26010XMNTBG handle ESD protection on its line interface pins?

The NCN26010XMNTBG provides 8 kV Human Body Model (HBM) ESD protection specifically on the LINEP and LINEN differential MDI pins - exceeding the 2 kV minimum specified in IEEE 802.3cg. This rating is verified per JESD22-A114 and ensures resilience against electrostatic discharge events common during field installation and maintenance. External ESD protection (e.g., ON Semiconductor ESD7241) is optional but recommended for mission-critical deployments. NCN26010XMNTBG's internal protection structure eliminates the need for discrete TVS diodes in most industrial use cases, reducing board area and component count.