KSZ8001SI - 10/100 Ethernet PHY, 48-SSOP | Microchip
MPN: KSZ8001SI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.0277 | $3.03 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
KSZ8001SI Overview
An Ethernet PHY is an interface IC that translates between a digital Ethernet Media Independent Interface and analog signaling over twisted-pair or fiber media. In the network hierarchy, the KSZ8001SI sits between a network controller or embedded processor and an Ethernet transformer or optical interface. Its MII support permits a parallel host connection, RMII reduces the host-side pin and signal burden, and SMII provides a serial alternative.
The verified device information identifies a 1.8 V CMOS design, 250 mW power consumption, operation over standard cables longer than 130 m, and support for MII, RMII, and SMII. LinkMD determines cable length and diagnoses faulty cables up to 200 m with stated accuracy of ±2 m. These capabilities make the device suitable for embedded Ethernet equipment, industrial controllers, network adapters, and test equipment.
The KSZ8001SI supports copper and fiber link modes, including 10BASE-T, 100BASE-TX, and 100BASE-FX. Its 48-BSSOP package is intended for surface-mount PCB assembly, while the supplied search results identify tube packaging for one ordering configuration. The MII, RMII, and SMII interfaces give system designers flexibility in host bus selection and board partitioning.
For copper links, the PHY requires appropriate external magnetics, termination, line-side filtering, and a compliant Ethernet transformer or coupling network. For 100BASE-FX, the external fiber interface must be designed for the selected optical device and link budget. The selected interface mode, clocking method, and host voltage must follow the manufacturer datasheet.
A critical design consideration is that advertised protocol support does not eliminate the need for PCB-level Ethernet compliance testing. Differential routing, grounding, magnetics placement, isolation boundaries, and power filtering can determine whether a nominal PHY implementation achieves reliable 10BASE-T and 100BASE-TX operation. This page consolidates verified product facts, sourcing data, interface options, and engineering guidance for design evaluation.
Drop-in alternatives for KSZ8001SI — 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 KSZ8001SI (same form factor and footprint) — differing in Package, Auto-Negotiation, Operating Temperature, Packaging, Product Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesKSZ8001SI Specifications
| Product Type | 10/100BASE-T/TX/FX Ethernet physical-layer transceiver |
| Supported Data Rates | 10 Mbit/s and 100 Mbit/s |
| Supported Media | 10BASE-T, 100BASE-TX, and 100BASE-FX |
| Host Interfaces | MII, RMII, and SMII |
| Supply Voltage | 1.8 V and 3.3 V |
| Core Design Voltage | 1.8 V CMOS |
| Power Consumption | 250 mW |
| Standard Cable Operation | 130 m or longer |
| LinkMD Diagnostic Range | Up to 200 m |
| LinkMD Cable-Length Accuracy | ±2 m |
| Package | 48-BSSOP, 0.295 in (7.50 mm) width |
| Mounting Type | Surface mount |
| Packaging | Tube |
| Number of PHY Channels | 1 channel |
| Interface Category | Ethernet physical layer |
KSZ8001SI 48-bssop, 0.295 in (7.50 mm) width Pin Configuration Guide
Pin configuration for KSZ8001SI (48-bssop, 0.295 in (7.50 mm) width package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for KSZ8001SI.
Refer to the datasheet for full pin configuration.
Typical Applications
KSZ8001SI is suitable for 6 applications: Embedded Ethernet Controller Interface, Industrial Controller Ethernet Port, Copper-to-Fiber Network Adapter, Network Interface Card, Cable Diagnostics and Network Maintenance, Low-Voltage Connected Embedded System.
Embedded Ethernet Controller Interface
The KSZ8001SI fits embedded systems whose network controller requires a flexible Ethernet host connection. Its verified MII, RMII, and SMII support lets the same 10/100 Mbit/s PHY operate with parallel, reduced-pin, or serial controller interfaces. Designers can place it between a processor or dedicated Ethernet controller and external copper-link circuitry while retaining 10BASE-T, 100BASE-TX, and 100BASE-FX support. The 1.8 V CMOS design is useful for low-voltage systems, and the listed 250 mW consumption supports early power budgeting. External magnetics, isolation, and line-side network design remain system-level requirements.
Recommended
Industrial Controller Ethernet Port
The KSZ8001SI can support a 10/100 Ethernet port in an industrial controller, provided the external design meets the required electrical, thermal, and regulatory objectives. It supports copper 10BASE-T and 100BASE-TX media as well as 100BASE-FX, allowing copper or optical networking choices. LinkMD can identify cable length and faulty cabling up to 200 m with the verified ±2 m accuracy, reducing commissioning time. MII, RMII, and SMII provide several host integration paths for controllers with different bus constraints. The supplied data does not establish an industrial temperature rating or qualification, so those requirements must be confirmed separately.
Recommended
Copper-to-Fiber Network Adapter
The KSZ8001SI is suited to equipment that needs both copper Ethernet and 100BASE-FX options in a single PHY family. The verified feature set covers 10BASE-T, 100BASE-TX, and 100BASE-FX at 10 Mbit/s and 100 Mbit/s. A copper port can use an Ethernet transformer and protection network, while a fiber port requires a compatible optical driver and receiver. This flexibility is valuable in network bridges, media converters, and embedded gateways that must match different physical layers without changing the host interface family. Keep the analog copper and optical paths physically separated and validate each media mode against the datasheet reference design.
Recommended
Network Interface Card
The KSZ8001SI provides the physical-layer element for a compact 10/100 network interface card. Its MII interface supports a conventional parallel host connection, while RMII and SMII can reduce host-side wiring in space-constrained designs. The 1.8 V CMOS core and 3.3 V support allow integration with compatible embedded or communications controllers, subject to the exact rail requirements in the datasheet. Designers should reserve space for the Ethernet transformer, RJ45 integration components, magnetics-side filtering, and ESD protection. The verified package is a 48-BSSOP, so the PCB footprint and pin map must be checked against the exact ordered device before layout release.
Recommended
Cable Diagnostics and Network Maintenance
The KSZ8001SI is useful in equipment where field cable faults must be identified quickly. LinkMD determines cable length and diagnoses faulty cables, with the verified KSZ8001 information specifying operation up to 200 m and ±2 m accuracy. Integrating this feature into a network-management path can help distinguish a bad cable or installation issue from a higher-level Ethernet problem. The diagnostic procedure and register interface must be implemented according to the manufacturer documentation. Because the supplied data does not specify a complete measurement tolerance across every cable type, field validation should use representative installations rather than relying only on a nominal accuracy figure.
Recommended
Low-Voltage Connected Embedded System
The KSZ8001SI can add Ethernet connectivity to a low-voltage embedded platform while preserving several host-interface choices. Its verified 1.8 V CMOS design, 1.8 V and 3.3 V supply operation, and listed 250 mW consumption provide useful starting points for power architecture. MII, RMII, or SMII allows the designer to match the processor interface and reduce wiring where appropriate. The PHY must be paired with suitable external Ethernet magnetics, filtering, and protection, and the host controller must support the selected interface timing. Before production use, verify operating temperature, supply sequencing, and all pin assignments against the manufacturer datasheet for the exact package suffix.
Recommended
Recommended Products Summary
Engineering reference data for KSZ8001SI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KSZ8001LI | KSZ8001L | KS8001S | KSZ8001S | KSZ8001LA3TR |
|---|---|---|---|---|---|---|
| Package | 48-BSSOP, 0.295 in (7.50 mm) width | 48-BSSOP listed in site MPN data; exact package details not independently supplied | 48-BSSOP family candidate; exact package details not independently supplied | 48-BSSOP identified in comparison data | 48-BSSOP identified in comparison data | 48-BSSOP family comparison candidate; exact package details not independently supplied |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
Key Differentiators
- Supports three host interface styles (vs KSZ8001S)
- Supports copper and fiber media modes (vs KS8001S)
- Includes defined cable diagnostics capability (vs KSZ8001LA3TR)
Design Notes
Route the Ethernet differential pairs as controlled-impedance transmission lines and keep the PHY-to-magnetics path short and symmetric. Separate the digital host-side circuitry from the analog line-side network, provide a continuous ground reference, and place the PHY supply bypass capacitors close to the relevant pins. The exact pin names and recommended layout geometry must be taken from the KSZ8001 manufacturer datasheet because the supplied search results do not include the complete pin table.
Build the power budget around the verified 1.8 V CMOS architecture and the listed 250 mW device consumption, while separately accounting for the external Ethernet transformer and any host-side circuitry. Verify the permitted 1.8 V and 3.3 V rail combinations, sequencing, decoupling, and tolerance limits in the datasheet before connecting a controller. Do not assume that the package-level power figure includes magnetics, protection components, or regulator losses.
Do not substitute a KSZ8001 family member solely because its name is similar. Confirm the exact package, pin numbering, strap options, supported host interface, media modes, supply limits, and reset or clock requirements for the candidate. In particular, the supplied data identifies KSZ8001SI as a 48-BSSOP, but it does not independently establish that every related suffix has identical pinout and parameter limits.
For 100BASE-FX implementations, keep the optical path and copper line-side path appropriately isolated and follow the manufacturer's reference layout for component placement and grounding. For 10BASE-T and 100BASE-TX, validate magnetics selection, termination, cable-side filtering, and ESD protection rather than relying only on nominal PHY functionality. Compliance testing should include the target cable lengths and representative link partners.
Compliance Information
The supplied verified product and distributor snippets do not explicitly state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or AEC-Q100 status. AEC-Q100 is marked not_applicable because this is an Ethernet interface IC and no automotive qualification claim was provided.
