LAN9355TI/PT - 3-Port 10/100 Managed Ethernet Switch
MPN: LAN9355TI/PT ✓ ActiveDrop-in alternatives for LAN9355TI/PT — 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 LAN9355TI/PT (same form factor and footprint) — differing in Package, Host Interface, Number of Ports.
LAN9355/PT
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LAN9355I/PT
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LAN9355TI/PT Maximum Ratings & Electrical Characteristics
| Device Type | 3-port managed Ethernet switch |
| Ethernet Data Rate | 10/100 Base-T/TX |
| Number of Ports | 3 ports |
| Management Interface | I2C |
| Host Interface | Dual MII/RMII/Turbo MII |
| Supply Voltage Range | 1.8 V to 3.3 V |
| Operating Temperature Range | -40°C to +85°C |
| Package | 80-TQFP-EP, 12 mm × 12 mm |
| Exposed Pad | Yes |
| Mounting Type | Surface mount |
| Packaging Type | Tape & Reel (TR) |
| Product Category | Ethernet switch controller |
| Target Applications | Consumer, embedded, and industrial electronics |
LAN9355TI/PT 80-tqfp-ep, 12 mm × 12 mm Pin Configuration Guide
Pin configuration for LAN9355TI/PT (80-tqfp-ep, 12 mm × 12 mm 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 LAN9355TI/PT.
Refer to the datasheet for full pin configuration.
Typical Applications
LAN9355TI/PT is suitable for 6 applications: Embedded Linux Network Appliance, Industrial Ethernet Gateway, Smart Building Controller, Consumer Network Appliance, Automated Test Equipment, Industrial Sensor Hub.
Embedded Linux Network Appliance
The LAN9355TI/PT fits an embedded Linux appliance that needs multiple 10/100 Ethernet connections without a separate switch ASIC. Its three integrated ports reduce board area and component count, while the I2C management path supports configuration alongside a processor bus interface. The 1.8 V to 3.3 V operating range accommodates common embedded processor rails. Designers must align the selected MII, RMII, or Turbo MII mode with the SoC, provide compliant clocking and reset behavior, and verify Linux driver support for the board's PHY address and interrupt arrangement.
Recommended
Industrial Ethernet Gateway
The LAN9355TI/PT is appropriate for an industrial gateway operating from -40°C to +85°C and requiring three 10/100 ports for local equipment, sensors, or service networks. Its integrated managed-switch architecture can reduce the number of discrete network components compared with separate PHY implementations. Industrial qualification of the finished product remains a system-level activity. The PCB should provide adequate exposed-pad grounding, isolated high-impedance copper routing for magnetics, robust input power filtering, and verified surge protection where required by the installation environment.
Recommended
Smart Building Controller
The LAN9355TI/PT can provide three wired 10/100 links in a smart-building controller that connects to lighting, access, or environmental equipment. The compact 80-pin TQFP exposed-pad package helps preserve board space compared with a discrete switching solution. The I2C interface provides a management path, while the configurable host interface allows connection to an embedded processor. Because building controllers can experience long cable runs and noisy power environments, use compliant Ethernet magnetics, solid grounding, isolated cable interfaces, and firmware recovery provisions that prevent a configuration fault from taking the entire network offline.
Recommended
Consumer Network Appliance
The LAN9355TI/PT suits a compact consumer appliance that needs to present multiple 10/100 connections through one host processor. Integrating switching can shorten board routing and reduce the number of components compared with adding a standalone three-port switch. The processor must supply the required MII/RMII/Turbo MII clocking, while the design must account for the exposed pad during assembly and enclosure design. Firmware should expose the port configuration, link status, and error recovery through a practical user interface so installation technicians can diagnose cable or port faults without specialized equipment.
Recommended
Automated Test Equipment
The LAN9355TI/PT can support automated test equipment that requires three independent 10/100 network connections for instrument control, fixture networking, and service access. Integrating the switch into the controller board can simplify the control topology and reduce external network hardware. The host interface timing and clock sources must remain deterministic, and the layout must keep Ethernet differential pairs controlled and separated from noisy power and switching circuitry. Validate link auto-negotiation, recovery after link loss, and sustained traffic at the temperature extremes expected by the equipment specification.
Recommended
Industrial Sensor Hub
The LAN9355TI/PT is useful in an industrial sensor hub that aggregates several wired sensor or service connections while operating across -40°C to +85°C. Three integrated 10/100 ports provide network segmentation without a separate switch board, and the small exposed-pad TQFP can fit a compact controller assembly. The design should include robust Ethernet magnetic coupling, surge-resistant interfaces, controlled power filtering, and careful separation between Ethernet routing and sensor analog sections. Firmware should monitor link status and provide controlled recovery so a disconnected peripheral cannot cause unnecessary service interruptions elsewhere on the hub.
Recommended
Recommended Products Summary
Engineering reference data for LAN9355TI/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LAN9355/PT | LAN9355I/PT |
|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 80-TQFP-EP (12 mm × 12 mm) | 80-TQFP-EP (12 mm × 12 mm) - same | 80-TQFP-EP (12 mm × 12 mm) - same |
| Device Type | Managed Ethernet switch | Managed Ethernet switch | Managed Ethernet switch |
| Number of Ports | 3 ports | 3 ports | 3 ports |
| Ethernet Data Rate | 10/100 Base-T/TX | 10/100 Base-T/TX | 10/100 Base-T/TX |
| Management Interface | I2C | I2C | I2C |
| Host Interface | Dual MII/RMII/Turbo MII | Dual MII/RMII/Turbo MII | Dual MII/RMII/Turbo MII |
| Supply Voltage Range | 1.8 V to 3.3 V | 1.8 V to 3.3 V | 1.8 V to 3.3 V |
Key Differentiators
- Integrated three-port managed switching (vs LAN9355/PT)
- Industrial-temperature ordering option (vs LAN9355I/PT)
- Compact integrated network interface (vs LAN9355/PT)
Design Notes
Treat the exposed pad as a required thermal and ground connection. Place a full-size ground-pad footprint under the package, retain the manufacturer-recommended solder mask and paste pattern, and provide nearby via stitching into the ground plane. Estimate the junction rise from total dissipation and the effective board thermal resistance, then compare the resulting junction temperature with the device limit of +85°C for the -40°C to +85°C grade.
Use the manufacturer's reference layout and pin-description table when assigning the 80-pin TQFP signals. Keep the MII/RMII/Turbo MII host traces short and controlled, isolate Ethernet differential pairs from switching nodes and high-current paths, and avoid routing them across the exposed-pad ground area. Confirm PHY address, strap, reset, reference-clock, and interrupt assignments before routing because incorrect configuration straps can change the interface behavior at power-up.
Place local supply-decoupling capacitors at the appropriate power pins using the values and placement specified in the manufacturer datasheet. Keep supply and ground planes continuous through the switching core, and verify startup sequencing when the host processor and Ethernet magnetics use different rails. Use the manufacturer's guidance for unused outputs, clock sources, and reset behavior; incorrect sequencing or an unclocked interface can prevent the switch from initializing reliably.
Compliance Information
No specific RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status was identified for this exact ordering code. AEC-Q100 is recorded as not applicable because LAN9355TI/PT is an industrial Ethernet switch rather than an automotive-qualified device.
