PIC18F2685-I/SO - 8-bit 40MHz 96KB Flash MCU w/ ECAN | Microchip
MPN: PIC18F2685-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.5 | $10.50 |
| 10 | $9.45 | $94.50 |
| 100 | $8.4 | $840.00 |
| 500 | $7.62 | $3,810.00 |
| 1,000 | $6.9 | $6,900.00 |
PIC18F2685-I/SO Overview
What is an 8-bit flash microcontroller? It is a single-chip computer built around an 8-bit data path, integrating CPU core, non-volatile Flash program memory, SRAM data memory, and a rich peripheral set (ADC, timers, communication controllers). In the product taxonomy this places the PIC18F2685-I/SO within microcontrollers -> microcontrollers (MCU) -> integrated circuits -> semiconductors. ECAN-equipped MCUs target real-time deterministic networking in industrial and automotive systems.
Key features include 96 KB (48K x 16) Flash, 3.25 KB (1.3K x 16) RAM, 1 KB EEPROM, a 10-bit / 8-channel ADC, two 8-bit and three 16-bit timers, two comparators, an 8-bit parallel slave port, and a USART with LIN support plus an MSSP (SPI/I2C). Enhanced features cover self-programmability, internal oscillator, ICD (in-circuit debug), and nanoWatt sleep modes drawing microamp-level currents for battery-aware applications.
Architecturally, the part uses a RISC Harvard core with a 16-bit instruction word, an 8-level hardware stack, 31 interrupt sources and a hardware multiplier that accelerates 8x8 bit operations. The integrated ECAN module supports CAN 2.0B active (with acceptance filters and buffers), simplifying node design in industrial sensor networks and automotive body/CAN networks.
Typical applications include CAN node endpoints (sensor clusters, industrial automation), automotive body and powertrain controllers (where ECAN is required), LIN/J2602 slave nodes, USB-to-CAN bridge companions, and low-power remote sensor nodes using nanoWatt sleep. For designers comparing pin-compatible parts, the PIC18F2680 (no ECAN), PIC18F2682 (smaller Flash) and PIC18F4685 (40/44-pin) share the ECAN feature with the PIC18F2685.
When designing with this device, allocate 4.2V to 5.5V on VDD, place decoupling close to the supply pins, route the ECAN RX/TX traces as a differential pair with 120-ohm termination, and reserve RC0/RC3 or the dedicated CCP/ICSP pins for in-circuit serial programming.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving engineers a faster engineering selection path.
Drop-in alternatives for PIC18F2685-I/SO — 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 PIC18F2685-I/SO (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Timers, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2680-I/SO
✅ Drop-In✓ In Stock
$6.95 / Unit
View Datasheet →PIC18F2682-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2685-E/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.8 / Unit
View Datasheet →PIC18F2680-E/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.75 / Unit
View Datasheet →PIC18F4585-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4685-I/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F2685-I/SO Maximum Ratings & Electrical Characteristics
| Family | PIC18F2xxx |
| Core | PIC 8-bit RISC Harvard |
| Max CPU Speed | 40 MHz |
| Program Memory | 96 KB Flash (48K x 16) |
| Data RAM | 3.25 KB (1.3K x 16) |
| EEPROM | 1 KB |
| I/O Pins | 25 |
| ADC | 10-bit, 8 channels |
| Timers | 2 x 8-bit, 3 x 16-bit |
| Comparators | 2 |
| Communication | ECAN, USART (LIN), MSSP (SPI/I2C) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Programming | ICSP (In-Circuit Serial Programming), Self-programming |
PIC18F2685-I/SO Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input / programming voltage / digital input only |
| Pin 2 | RA0/AN0 — Digital I/O / analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / analog input channel 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / analog input channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / analog input channel 4 / SPI slave select |
| Pin 8 | OSC1/CLKI/RA7 — Oscillator input / external clock in / digital I/O |
| Pin 9 | OSC2/CLKO/RA6 — Oscillator output / clock out / digital I/O |
| Pin 10 | RC0/T1OSO/T13CKI — Digital I/O / Timer1 oscillator output / Timer1/3 clock input |
| Pin 11 | RC1/SOSI/ECCP2 — Digital I/O / SPI data / Enhanced CCP2 output |
| Pin 12 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Digital I/O / SPI data out |
| Pin 16 | RC6/TX/CK — Digital I/O / USART async transmit / USART sync clock |
| Pin 17 | RC7/RX/DT — Digital I/O / USART async receive / USART sync data |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply (5V) |
| Pin 20 | RB0/AN10/INT0 — Digital I/O / analog input / external interrupt 0 |
| Pin 21 | RB1/AN8/INT1 — Digital I/O / analog input / external interrupt 1 |
| Pin 22 | RB2/AN8/INT2 — Digital I/O / analog input / external interrupt 2 |
| Pin 23 | RB3/AN9/CCP2 — Digital I/O / analog input / CCP2 output |
| Pin 24 | RB4/AN11 — Digital I/O / analog input |
| Pin 25 | RB5/AN12 — Digital I/O / analog input |
| Pin 26 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 27 | RB7/PGD — Digital I/O / ICSP data |
| Pin 28 | VSS — Ground reference (return) |
Typical Applications
PIC18F2685-I/SO is suitable for 6 applications: Industrial CAN Node / Sensor Hub, Automotive Body Electronics / CAN Node, USB-to-CAN Bridge Companion, Battery-Powered Remote Sensor Node, Motor Control and BLDC / Stepper Driver Board, HVAC / Building Automation Controller.
Industrial CAN Node / Sensor Hub
The PIC18F2685-I/SO is purpose-built for industrial CAN networks thanks to its integrated ECAN 2.0B active controller. It connects to a 5V CAN transceiver such as the MCP2551 or TJA1050, providing hardware acceptance filtering, multiple transmit buffers and deterministic bus arbitration without burdening the CPU. The 96 KB Flash accommodates CANopen or DeviceNet protocol stacks and Modbus bridging layers, while the 25 I/O drive digital sensors and actuators. ECAN reduces firmware complexity versus an external CAN controller, freeing the 40 MHz PIC18 core to handle real-time sensor reads and PWM outputs in factories and process plants.
Recommended
Automotive Body Electronics / CAN Node
The PIC18F2685-I/SO is widely used in automotive body electronics where ECAN 2.0B and 5V operation are required. It handles window lifters, mirror controls, lighting clusters and seat modules, reading switches and driving relays or MOSFETs. Its 10-bit ADC samples sensor inputs while the USART/LIN block supports LIN sub-bus slaves. The PIC18F2685-I/SO is industrial grade (-40C to +85C); for under-hoon use, the AEC-Q100-grade PIC18F4685 in the same family is preferred. The 96 KB Flash stores diagnostic firmware and CAN bootloader image with self-programming support.
Recommended
USB-to-CAN Bridge Companion
For USB-to-CAN bridges, the PIC18F2685-I/SO handles the CAN side while a USB host MCU manages the USB link, or vice versa. Its ECAN 2.0B controller, 3.25 KB RAM and 96 KB Flash make it suitable for protocol translation firmware, message filtering and buffering between CAN frames and a host-side serial interface. The MSSP (SPI/I2C) block can talk to a USB-UART bridge IC, while the USART (LIN) provides diagnostic passthrough. The 28-SOIC footprint keeps the bridge board compact for field engineers' laptops and bench tools.
Recommended
Battery-Powered Remote Sensor Node
Using the PIC18F2685-I/SO's nanoWatt sleep modes, designers can build battery-powered remote sensor nodes that periodically wake, sample, transmit over CAN/LIN and return to deep sleep. Sleep currents in the microamp range (with the ADC and ECAN off) extend battery life across years of maintenance-free operation. The internal oscillator eliminates external crystals for cost-sensitive nodes, while the 1 KB EEPROM stores calibration and node-identity data across power cycles. CAN wakes the node only when an external command frames the node ID, minimizing bus activity.
Recommended
Motor Control and BLDC / Stepper Driver Board
The PIC18F2685-I/SO drives small BLDC and stepper motors in industrial automation. Its three 16-bit timers generate complementary PWM outputs to FET half-bridges, while the 10-bit ADC samples back-EMF and current-sense amplifiers for closed-loop control. ECAN provides deterministic command bus integration into factory networks, allowing synchronized multi-axis motion. The 96 KB Flash fits state-space or field-oriented control (FOC) libraries, and the 25 I/O handle Hall sensors, end-stops and encoder inputs without external glue logic.
Recommended
HVAC / Building Automation Controller
In HVAC and building-automation controllers, the PIC18F2685-I/SO manages CAN or LIN sub-networks that interconnect thermostats, damper actuators, fan coils and chiller controllers. The USART (LIN) connects to J2602 slave nodes, while ECAN connects the controller to the building's main BMS bus. The 10-bit ADC reads temperature and humidity sensors, and the comparators trip safety thresholds without CPU intervention. The 28-SOIC footprint fits into the small enclosures typical of wall-mounted HVAC controllers, and nanoWatt modes save power when displays are inactive.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2685-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2680-I/SO | PIC18F2682-I/SO | PIC18F2685-E/SO | PIC18F2680-E/SP | PIC18F4585-I/SP | PIC18F4685-I/PT |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC (SO) | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SPDIP/SP - same family footprint variant | 44-TQFP - different package |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 96 KB | 96 KB - same | 80 KB (-17%) | 96 KB - same | 96 KB - same | 96 KB - same | 96 KB - same |
| RAM | 3.25 KB | 3.25 KB - same | 2.25 KB (-31%) | 3.25 KB - same | 3.25 KB - same | 3.25 KB - same | 3.25 KB - same |
| CAN Module | ECAN 2.0B active | CAN 1.0 | ECAN 2.0B active | ECAN 2.0B active - same | CAN 1.0 | ECAN 2.0B active | ECAN 2.0B active |
| Operating Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) | -40 C to +85 C | -40 C to +85 C |
| I/O Pins | 25 | 25 - same | 25 - same | 25 - same | 25 - same | 36 (40-pin) | 36 (44-pin) |
| Max Frequency | 40 MHz | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same |
Key Differentiators
- Integrated ECAN 2.0B active controller on-chip (vs PIC18F2680-I/SO)
- Full 96 KB Flash vs smaller Flash variants (vs PIC18F2682-I/SO)
- Extended temperature grade option in same package (vs PIC18F2685-I/SO (industrial))
- 28-SOIC footprint in Microchip's PIC18 CAN family (vs PIC18F4685-I/PT)
Design Notes
The PIC18F2685-I/SO operates from a single 4.2 V to 5.5 V supply on VDD (pins 11 and 19). Place a 100 nF decoupling capacitor within 5 mm of each VDD pin and a bulk 10 uF tantalum or ceramic capacitor on the rail. The internal regulator derives the 2.5 V core voltage; no external core decoupling is required beyond the pin-level bypass caps. In battery-powered designs, switch to nanoWatt sleep with the ECAN and ADC off to drop quiescent current to microamp levels.
Route the CAN bus as a 120-ohm-impedance differential pair from the ECAN TX/RX pins through the MCP2551 or TJA1050 transceiver to the bus connector. Place the transceiver within 25 mm of the MCU, keep stub lengths under 30 mm, and place 120-ohm termination resistors at each end of the bus. Keep the ECAN traces away from PWM, switching supply and crystal traces. The 28-SOIC footprint uses pin 11/28 (VDD) and pin 12/27 (VSS) for power; route power planes accordingly to minimize ground bounce.
Do not confuse the industrial -I grade (-40 C to +85 C) with the extended -E grade (-40 C to +125 C); choose PIC18F2685-E/SO for outdoor enclosures. The CAN 2.0B active mode (ECAN) is not the same as CAN 1.0; firmware written for PIC18F2680's CAN 1.0 register set will not run unmodified on the PIC18F2685. Always assert MCLR with a proper RC delay or reset supervisor to avoid code-execution lockups after brownouts. Reserve RB6/RB7 (PGC/PGD) for ICSP and never repurpose them as outputs in production designs.
Keep the crystal (or resonator) traces short and symmetric if using an external OSC. If using the internal oscillator at 40 MHz, configure OSCCON to select HFINTOSC and disable the OSC1/OSC2 pins as analog to save current. Place C1+/C1- or CCP PWM traces away from analog AN0-AN12 to avoid coupling. For ADC accuracy, route AVSS directly to the analog ground plane and add a small ferrite bead between VDD and AVDD.
Compliance Information
RoHS and lead-free compliant per Microchip product page; REACH compliant. Industrial temperature grade only; not AEC-Q100 qualified - choose PIC18F4685 for AEC-Q100 automotive. Conflict-minerals declaration available from Microchip.
