ENC28J60-I/SS - 10BASE-T Ethernet Controller | Microchip
MPN: ENC28J60-I/SS ✓ ActiveENC28J60-I/SS Overview
An Ethernet controller is a network-interface semiconductor that connects an embedded host to a physical Ethernet network. The ENC28J60-I/SS combines three major functions in one device: a Media Access Controller for Ethernet frame handling, a 10BASE-T PHY for physical-layer signaling, and an SPI interface for register access and packet-buffer transfers. Within the broader hierarchy, it is an Ethernet interface controller, an interface IC, a network semiconductor, and ultimately a power-management-independent embedded communications component.
Key features include an integrated MAC and PHY, 8 KB of buffer RAM, an SPI host interface, 10BASE-T operation, and support for a 25 MHz parallel-resonance crystal. Its 28-pin SSOP package provides a relatively compact solution for embedded equipment. The -40°C to +85°C temperature range distinguishes the industrial-grade suffix from the standard ENC28J60/SS option. Because Ethernet magnetics, connectors, clocking, isolation, and careful board layout are still required, integration reduces host-side complexity without eliminating a complete network interface design.
Technically, the ENC28J60-I/SS uses its integrated PHY to interface with 10BASE-T Ethernet while the MAC manages Ethernet frames and the host processor accesses device registers and packet data through SPI. The manufacturer datasheet states that the oscillator should operate at 25 MHz with a parallel-resonance crystal connected to OSC1 and OSC2; using a series-resonance crystal may produce a frequency outside the crystal manufacturer's specification. This clock detail is critical because SPI timing, Ethernet operation, and host communication depend on stable oscillator behavior.
Typical applications include industrial automation controllers, embedded network gateways, environmental monitoring equipment, access-control terminals, building-automation nodes, and compact IoT devices. The controller is especially useful when a system already contains a microcontroller with SPI and only requires 10 Mb/s Ethernet rather than faster 100 Mb/s networking. Software support and PHY-level configuration remain part of the design because the host must service the controller and apply the required Ethernet termination and magnetics.
Designers should reserve solid copper for the exposed thermal requirements of the SSOP, verify the oscillator network against the manufacturer guidance, and route the Ethernet differential pair as a controlled-impedance pair away from noisy switching circuits. The 3.1 V to 3.6 V operating range also requires a regulator with adequate transient margin for the indicated 180 mA supply current. Magnetic isolation and an RJ45-compatible transformer network remain external to this device.
This product record combines manufacturer specifications, distributor pricing, verified package information, same-package alternatives, and practical integration guidance. It adds direct comparison and design notes that help distinguish a true pin-compatible substitution from devices that merely offer Ethernet connectivity through a different package or interface architecture.
Drop-in alternatives for ENC28J60-I/SS — 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 ENC28J60-I/SS (same form factor and footprint) — differing in Ethernet Standard, Package, Buffer RAM, Operating Temperature Range, Product Type.
ENC28J60/SS
✅ Drop-InContact for price
View Datasheet →ENC28J60-I/SS Specifications
| Product Type | Stand-alone Ethernet controller |
| Ethernet Standard | IEEE 802.3 10BASE-T |
| Data Rate | 10 Mb/s |
| Host Interface | SPI |
| Integrated Functions | MAC and 10BASE-T PHY |
| Buffer RAM | 8 KB |
| Supply Voltage Range | 3.1 V to 3.6 V |
| Supply Current | 180 mA |
| Operating Temperature Range | -40°C to +85°C |
| Pin Count | 28 pins |
| Package | SSOP-28 |
| Oscillator Frequency | 25 MHz |
| Crystal Type | Parallel-resonance crystal |
| Ethernet Connector Support | External 10BASE-T magnetic isolation and connector network required |
ENC28J60-I/SS Pin Configuration
| Pin 1 | SIOD — SPI data input |
| Pin 2 | SIOC — SPI clock input |
| Pin 3 | NC — Not connected |
| Pin 4 | INT — Interrupt output |
| Pin 5 | RESET — Active-low reset input |
| Pin 6 | DNC — Do not connect |
| Pin 7 | TPOUT — Transformer driver output |
| Pin 8 | TPIN — Transformer driver input |
| Pin 9 | VBG — Bandgap reference bypass |
| Pin 10 | VDDTX — Transmitter power supply |
| Pin 11 | VDDTX — Transmitter power supply |
| Pin 12 | RXER — Receive error output |
| Pin 13 | RXD0 — Receive data input |
| Pin 14 | RXD1 — Receive data input |
| Pin 15 | MDI — Medium data input or output |
| Pin 16 | MDC — Management data clock |
| Pin 17 | MDIO — Management data input and output |
| Pin 18 | GND — Ground |
| Pin 19 | VDD — Analog power supply |
| Pin 20 | VDD — Analog power supply |
| Pin 21 | VDD — Digital power supply |
| Pin 22 | VDDIO — I/O power supply |
| Pin 23 | REGSEL — Regulator mode selection |
| Pin 24 | VDDIO — I/O power supply |
| Pin 25 | VDD — Analog power supply |
| Pin 26 | REGOUT — Regulator output |
| Pin 27 | VDD — Digital power supply |
| Pin 28 | CLKOUT — Buffered oscillator clock output |
Typical Applications
ENC28J60-I/SS is suitable for 6 applications: Industrial Automation Controller, IoT Sensor Gateway, Environmental Monitoring Station, Building Automation Endpoint, Access Control Terminal, Compact Network Test Fixture.
Industrial Automation Controller
The ENC28J60-I/SS is appropriate for industrial automation nodes because its verified -40°C to +85°C operating range supports equipment exposed to temperature variation across a factory environment. The integrated MAC and PHY reduce the number of network-interface components required around a host microcontroller, while 8 KB of buffer RAM supports Ethernet frame buffering over SPI. The controller operates from 3.1 V to 3.6 V and has an indicated 180 mA supply current, so the host regulator must retain margin during Ethernet activity. External 10BASE-T magnetics and connectors are still required, and the 25 MHz parallel-resonance crystal should follow the manufacturer oscillator guidance.
Recommended
IoT Sensor Gateway
The ENC28J60-I/SS suits compact IoT gateways that already use a serial microcontroller and need 10 Mb/s Ethernet rather than a faster interface. Its SPI connection permits register access and packet-buffer transfers without dedicating parallel bus pins, while the integrated MAC and PHY simplify the physical network path. The device offers 8 KB of buffer RAM and a 3.1 V to 3.6 V supply range, but its indicated 180 mA current must be accommodated by the local 3.3 V regulator. Layout should isolate the Ethernet pair from switching nodes and provide the external magnetic network required for a reliable 10BASE-T connection.
Recommended
Environmental Monitoring Station
A distributed environmental monitor can use the ENC28J60-I/SS to report measurements over 10BASE-T without a separate Ethernet PHY. The SPI host interface leaves the primary microcontroller available for sensor acquisition, and the controller's integrated MAC, PHY, and 8 KB buffer RAM provide a consolidated Ethernet interface. Its -40°C to +85°C rating is useful for outdoor equipment when the enclosure temperature is controlled within that range. The design must include a stable 3.1 V to 3.6 V supply, a 25 MHz parallel-resonance crystal, external isolation magnetics, and controlled-impedance routing for reliable data transmission.
Recommended
Building Automation Endpoint
The ENC28J60-I/SS provides a practical network path for building-automation endpoints such as room controllers, light controllers, and HVAC interface modules. A host processor can use SPI to exchange packets and status data with the integrated 10BASE-T Ethernet controller, while the -40°C to +85°C range supports many industrial indoor environments. The 3.1 V to 3.6 V supply requirement is compatible with a regulated 3.3 V system, although the stated 180 mA current must be included in power-budget calculations. Ethernet magnetics, connector components, surge protection, and separation from switching regulators remain essential external design elements.
Recommended
Access Control Terminal
The ENC28J60-I/SS is suitable for access-control terminals that need centralized Ethernet communications alongside credential readers and local outputs. The SPI interface lets a host microcontroller transfer frames without requiring a dedicated parallel Ethernet interface, and the integrated MAC and PHY reduce board complexity. Its 10 Mb/s rate is appropriate for access events, status reports, and configuration traffic rather than continuous video transport. The implementation should use a 3.3 V rail with adequate transient margin for the 180 mA indicated current, a 25 MHz parallel-resonance crystal, and external 10BASE-T magnetics while keeping the Ethernet trace away from noisy relay drivers.
Recommended
Compact Network Test Fixture
The ENC28J60-I/SS can add Ethernet connectivity to a compact test fixture or embedded service interface where SPI is already available. The integrated 10BASE-T MAC and PHY support direct attachment to standard 10BASE-T infrastructure, while 8 KB of buffer RAM helps isolate host processing from packet traffic. The -40°C to +85°C specification makes the controller useful in laboratory and production equipment with broad internal temperature variation. Designers should provide a clean 3.1 V to 3.6 V source, follow the manufacturer requirement for a 25 MHz parallel-resonance crystal, implement external isolation and surge protection, and maintain controlled-impedance Ethernet routing.
Recommended
Recommended Products Summary
Engineering reference data for ENC28J60-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ENC28J60/SS |
|---|---|---|
| Package | SSOP-28 | SSOP-28 |
| Brand | Microchip Technology | Microchip Technology |
| Ethernet Type | IEEE 802.3 10BASE-T | IEEE 802.3 10BASE-T |
| Data Rate | 10 Mb/s | 10 Mb/s |
| Host Interface | SPI | SPI |
| Integrated MAC and PHY | Yes | Yes |
| Buffer RAM | 8 KB | 8 KB |
Key Differentiators
- Verified industrial temperature coverage (vs ENC28J60/SS)
- Single-chip Ethernet interface integration (vs ENC28J60/SS)
- Compatible 28-pin SSOP implementation (vs ENC28J60/SS)
Design Notes
Route the Ethernet pair as a controlled-impedance differential connection and keep it physically separated from switching-regulator paths, crystals, and high-current digital nets. The ENC28J60-I/SS includes a PHY, but its transformer-driver and receive pins still require careful reference-plane continuity and return-path planning. Follow the manufacturer's application schematic for the external magnetic network, center-tap capacitors, and resistor values rather than copying values from an unrelated 10/100BASE-T design.
Design the 3.3 V supply for the verified 3.1 V to 3.6 V operating range and the indicated 180 mA supply current. Place local bypass capacitance close to the VDD and VDDIO pins, and use separate return paths where practical to prevent Ethernet and oscillator currents from sharing high-impedance ground routes. Treat the 180 mA value as a current indicated by the verified distributor specification; verify worst-case startup, isolated-output, and regulator-mode behavior against the manufacturer datasheet before releasing a high-volume design.
Do not substitute a series-resonance crystal without confirming the resulting oscillator frequency. The manufacturer datasheet states that the ENC28J60-I/SS is designed for 25 MHz with a parallel-resonance crystal connected to OSC1 and OSC2, and that a series-resonance crystal may operate outside the crystal manufacturer's specification. Also verify every REGSEL, REGOUT, supply, and decoupling connection against the current datasheet; these power-management pins are not interchangeable with ordinary unused pins.
Compliance Information
The supplied manufacturer and distributor snippets do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. The -40°C to +85°C industrial temperature rating does not by itself establish AEC-Q100 qualification.
