MCP2551-I - High-Speed CAN Transceiver, 1 Mb/s, 8-Pin DIP/SOIC | Microchip
MPN: MCP2551-I ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.02 | $2.02 |
| 10 | $1.82 | $18.20 |
| 100 | $1.55 | $155.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.15 | $1,150.00 |
MCP2551-I Overview
A CAN transceiver is a physical-layer device that translates the digital transmit/receive signals from a CAN controller into the differential voltage levels (CANH/CANL) required on the bus. It belongs to the broader hierarchy of interface ICs, sitting between protocol controllers (such as MCP2515 standalone CAN controllers) and the physical wiring harness, and ultimately forms part of the in-vehicle or industrial networking infrastructure. CAN transceivers like the MCP2551-I are the bedrock of automotive OBD-II, CANopen, and DeviceNet networks.
Key features include ±80V bus fault protection on CANH and CANL, a high-noise immunity design (>1V common-mode range), thermal shutdown protection, and an automatic thermal slope control that reduces emissions at lower data rates. The device has three operating modes: High-Speed, Slope-Control, and Standby, with the mode selected via the RS pin. A VREF output (2.5V typical) is provided as a voltage reference for the CAN controller.
The MCP2551-I uses a bipolar process technology and incorporates slope control to minimize EMI by limiting the rise/fall times of CANH and CANL. Its differential receiver provides excellent noise immunity with a typical hysteresis of 100 mV. The transceiver operates across -40°C to +125°C industrial temperature range, making it suitable for under-hood automotive and rugged industrial applications.
Typical applications include automotive body and chassis networks, industrial CANopen and DeviceNet nodes, OBD-II vehicle diagnostics, HVAC and elevator control systems, and medical instrumentation interconnects. Designers frequently pair the MCP2551-I with the MCP2515 standalone CAN controller for full CAN node implementations.
A critical design consideration is bus termination: the CAN bus requires 120 Ω resistors at each end of the bus segment, and these are typically not integrated in the MCP2551-I. The RS pin should be tied high through a resistor to VCC for high-speed operation or connected to ground through a resistor to enable slope-control mode for lower EMI at reduced data rates.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including cross-brand equivalents and pin-compatible migration paths to the MCP2561.
Drop-in alternatives for MCP2551-I — 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:
MCP2561-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
MCP2561-I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
SN65HVD251DR
✅ Drop-In📋 Reference alternative (not in catalog)
SN65HVD251P
✅ Drop-In📋 Reference alternative (not in catalog)
TJA1050T/N1
✅ Drop-In📋 Reference alternative (not in catalog)
PCA82C251/N3,112
✅ Drop-In📋 Reference alternative (not in catalog)
MCP2551-I Specifications
| Product Type | CAN Transceiver |
| Data Rate | 1 Mb/s (max) |
| Supply Voltage | 4.5 V to 5.5 V |
| Common-Mode Range | -7 V to +12 V (operational); +/-80 V fault tolerant |
| Bus Fault Protection | +/-80 V on CANH, CANL |
| Operating Temperature | -40 C to +125 C (industrial) |
| Package | 8-Pin PDIP (P) or 8-Pin SOIC (SN) |
| Mounting Type | Through-Hole (PDIP) or Surface Mount (SOIC) |
| Number of Pins | 8 |
| Standards Compliance | ISO-11898 |
| Operating Modes | High-Speed, Slope-Control, Standby |
| RoHS Status | Compliant (per Microchip product page) |
| Lead-Free | Yes |
MCP2551-I Pin Configuration
| Pin 1 | TXD — Transmit Data input from CAN controller |
| Pin 2 | VSS — Ground reference |
| Pin 3 | VCC — Supply voltage (4.5V to 5.5V) |
| Pin 4 | RXD — Receive Data output to CAN controller |
| Pin 5 | VREF — Voltage reference output (2.5V typical) |
| Pin 6 | CANL — Low-level CAN bus line |
| Pin 7 | CANH — High-level CAN bus line |
| Pin 8 | RS — Mode select: high-speed, slope-control, or standby |
Typical Applications
MCP2551-I is suitable for 6 applications: Automotive CAN Bus Networks, Industrial CANopen and DeviceNet Nodes, OBD-II Vehicle Diagnostics Interfaces, Medical Instrumentation Interconnects, Building Automation and HVAC Control, Elevator and Escalator Control Systems.
Automotive CAN Bus Networks
The MCP2551-I is widely deployed in automotive body and chassis CAN networks where its ISO-11898 compliance, +/-80V bus fault tolerance, and -40 C to +125 C industrial temperature range meet the demanding requirements of under-hood and cabin modules. Its differential CANH/CANL interface connects to twisted-pair bus wiring carrying 5V differential signaling at up to 1 Mb/s, while the 5V supply rail accommodates standard automotive ECU power budgets. Designers typically pair the MCP2551-I with the MCP2515 standalone CAN controller for full ISO 11898-1/2/3 node implementations. The device's high common-mode rejection (typically >25 V) ensures robust operation in electrically noisy environments near ignition systems and motor drives.
Recommended
Industrial CANopen and DeviceNet Nodes
In industrial CANopen and DeviceNet fieldbus nodes, the MCP2551-I provides the physical-layer interface between a microcontroller's CAN peripheral and the bus cabling. CANopen typically operates at 125 kb/s to 1 Mb/s, well within the MCP2551-I's 1 Mb/s envelope, and the industrial temperature grade ensures reliable operation in factory automation cabinets. The device's slope-control mode reduces EMI emissions in cabinet-wiring-dense installations where multiple CAN segments run in parallel. Its 5V supply rail simplifies integration with 5V-tolerant industrial MCUs and PLCs. Design tip: use a 120 ohm termination resistor at each bus end, and place the MCP2551-I physically close to the bus connector to minimize stub length and signal reflections.
Recommended
OBD-II Vehicle Diagnostics Interfaces
The MCP2551-I is a popular choice for OBD-II diagnostic scan tools and vehicle telemetry interfaces that communicate with a car's CAN bus via the standardized OBD-II connector (SAE J1962). Its ISO-11898 compliance ensures interoperability with all CAN-based OBD-II vehicles, and the 5V supply is well suited to USB-powered scan tools. The high common-mode voltage range allows the interface to handle ground offsets between the scan tool and the vehicle chassis, which can vary by several volts during cranking. The MCP2551-I's fault tolerance on CANH/CANL protects the scan tool from accidental shorts to the 12V or 24V battery rail. Its low standby current makes it suitable for always-on telematics units that wake periodically to query the bus.
Recommended
Medical Instrumentation Interconnects
In medical device networks that use CAN as the internal interconnect (such as hospital bed systems, infusion pumps, and patient monitors), the MCP2551-I provides a reliable, low-cost physical layer. Medical CAN networks typically operate at 250 kb/s to 500 kb/s for noise immunity, well below the MCP2551-I's 1 Mb/s limit. The industrial temperature grade accommodates the thermal environment of clinical equipment, and the differential signaling provides strong immunity to EMI from MRI rooms, electrosurgical devices, and switching power supplies. The MCP2551-I's small 8-pin PDIP or SOIC footprint allows integration into compact handheld instrument designs. Note: medical safety certification (IEC 60601) is the system integrator's responsibility, not the transceiver's.
Recommended
Building Automation and HVAC Control
Building automation systems often use CAN-based protocols (BACnet over CAN, or vendor-specific implementations) for HVAC controllers, damper actuators, and energy recovery ventilation. The MCP2551-I's robust fault tolerance and wide common-mode range suit the long cable runs and potential ground loops encountered in commercial building installations. Its 5V supply integrates cleanly with the 5V rails typical in HVAC control boards, and its industrial temperature grade ensures operation in unconditioned mechanical rooms. Design tip: for HVAC bus segments longer than 40 meters, enable slope-control mode on the MCP2551-I to reduce reflections and EMI. The transceiver's low standby current also supports energy-saving standby modes for off-hours operation.
Recommended
Elevator and Escalator Control Systems
Elevator and escalator control systems rely on CAN bus for car-call panels, drive controllers, and door operators due to CAN's deterministic arbitration and fault tolerance. The MCP2551-I's 1 Mb/s capability supports real-time communication across multiple floors, while its industrial temperature grade suits elevator machine room environments that can reach 60 C ambient. The +/-80V bus fault tolerance protects against the inductive kickback from motor contactors and door solenoids, reducing field failures and warranty costs. The 8-pin PDIP package is favored for its ease of hand-rework in service depots. Designers typically use a dual-MCP2551-I redundant configuration for safety-critical door interlock communication, with the second transceiver on a separate bus segment.
Recommended
Recommended Products Summary
Engineering reference data for MCP2551-I — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCP2561-I/P | MCP2561-I/SN | SN65HVD251DR | SN65HVD251P | TJA1050T/N1 | PCA82C251/N3,112 |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Texas Instruments | Texas Instruments | NXP Semiconductors | NXP Semiconductors |
| Package | 8-Pin PDIP or 8-Pin SOIC | 8-Pin PDIP - same | 8-Pin SOIC - same | 8-Pin SOIC - same | 8-Pin PDIP - same | 8-Pin SOIC - same | 8-Pin PDIP - same |
| Data Rate (max) | 1 Mb/s | 1 Mb/s | 1 Mb/s | 1 Mb/s | 1 Mb/s | 1 Mb/s | 1 Mb/s |
| Supply Voltage | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V |
| ISO-11898 Compliance | Yes (full) | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +125 C |
Key Differentiators
- Highest bus fault tolerance in its class (vs SN65HVD251)
- Same-brand drop-in migration path with enhanced EMC (vs MCP2561-I/P)
- Wide operating temperature range (vs SN65HVD251P)
Design Notes
Estimated: The CAN bus requires 120 ohm termination resistors at each end of the bus segment. The MCP2551-I does not include integrated termination. Place the 120 ohm resistor (typically 1% tolerance) physically at the bus connector, not at the transceiver, to maximize bus signal integrity. Missing termination is the #1 cause of CAN communication failures, especially at higher data rates (500 kb/s to 1 Mb/s). For split termination (recommended for EMI-sensitive designs), use two 60 ohm resistors in series with a 4.7 nF capacitor to ground at the midpoint.
Keep the CANH and CANL traces as a matched-impedance differential pair (100-120 ohm differential impedance) and route them away from noisy digital lines. The stub length from the bus to the transceiver's CANH/CANL pins should be kept under 30 mm to minimize reflections. Place a small common-mode choke (e.g., 100 uH at 100 MHz) in series with CANH/CANL near the bus connector for additional EMI immunity in noisy industrial environments. The VCC pin should be decoupled with a 100 nF ceramic capacitor placed within 3 mm of the pin, plus a 10 uF bulk capacitor nearby.
Estimated: At 5V supply and dominant bus state with 60 ohm bus load (worst case, two 120 ohm terminations in parallel), the MCP2551-I draws approximately 50-70 mA. At recessive state, current drops to under 10 mA. Total power dissipation is dominated by the bus load, not the logic supply. For supply design, budget at least 100 mA per MCP2551-I node. The device includes thermal shutdown at approximately 165 C junction temperature; ensure junction temperature stays below 125 C in your thermal design. The exposed thermal behavior of the PDIP package is generally adequate for these current levels without heatsinking.
Use the RS pin to enable slope-control mode for CAN bus segments longer than ~30 meters or for data rates below 125 kb/s. Slope control slows the rise/fall times of CANH/CANL, reducing high-frequency EMI emissions by approximately 20 dB. Tie RS high through a 10 kohm resistor for high-speed mode, or through a 100 kohm resistor to ground for slope-control mode. The VREF output provides a stable 2.5V reference for the CAN controller's input threshold; bypass VREF with a 100 nF capacitor if used by the controller. Verify ground reference between the MCP2551-I and the CAN controller; ground offsets > 1V can cause RXD communication errors.
Compliance Information
RoHS and lead-free per Microchip product page. The 'I' suffix denotes industrial temperature grade (-40 C to +125 C), not AEC-Q100 qualification. For AEC-Q100 qualified CAN transceivers, consider MCP2561-Q1 or MCP2515-Q1.
