PIC18F4682-I/ML - 8-bit 40MHz 80KB Flash MCU 44-QFN | Microchip
MPN: PIC18F4682-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.45 | $84.50 |
| 100 | $7.38 | $738.00 |
| 500 | $6.55 | $3,275.00 |
| 1,000 | $5.92 | $5,920.00 |
PIC18F4682-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O onto one silicon die. The PIC18 family sits within Microchip's 8-bit PIC portfolio as an enhanced architecture with 16-bit wide instructions, hardware multiply, and C-optimized design, making it a step up from baseline and mid-range PIC microcontrollers and a popular choice for cost-sensitive embedded control. The PIC18F4682 belongs to the PIC18F4680/4682/4685 sub-family, which adds the ECAN (Enhanced Controller Area Network) peripheral for automotive and industrial CAN bus nodes.
Key features of the PIC18F4682-I/ML include 80 KB (40K x 16) self-programmable Flash, 3.3 KB RAM, 1 KB EEPROM, 36 digital I/O pins, a 10-bit ADC with up to 11 channels, an Enhanced USART, MSSP (SPI/I2C), two CCP/ECCP modules, two 8-bit timers plus three 16-bit timers, and an ECAN module. The nanoWatt technology offers multiple power-managed modes (Idle, Sleep, and alternate clock sources) that drop supply current into the microamp range during idle periods, extending battery life in low-duty-cycle applications.
The architecture combines a Harvard-bus RISC core with a 16-bit instruction word and an 8-bit data path, a hardware 8x8 multiplier for fast arithmetic, an interrupt controller with vectored priorities, and an internal oscillator block. The QFN-44 package with exposed pad gives low thermal resistance for high-clock industrial environments, and the on-board In-Circuit Serial Programming (ICSP) and In-Circuit Debug (ICD) interfaces allow direct Flash programming through two pins without an external programmer.
Typical applications include CAN-connected industrial sensor nodes, automotive body and comfort electronics, HVAC controllers, building-automation gateways, USB-to-CAN bridges, and embedded motor-control front ends. The combination of ECAN, 10-bit ADC, and ample Flash makes it well suited to multi-node networks where each node runs local control and reports back through the bus.
When designing with this part, allocate the ECAN pins (CANTX/CANRX) and the ICP/ICSP pins (PGD/PGC) early in the schematic; these are multiplexed and remapping them mid-layout is painful. Use the exposed thermal pad as a thermal and ground anchor - a continuous ground plane under the QFN is essential for the 40 MHz clock and the high-current I/O switching to keep emissions low.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the standalone manufacturer datasheet. Engineers comparing PIC18F4682 with PIC18F4685 or PIC18F4585 will find the parametric comparison_table below particularly useful.
Drop-in alternatives for PIC18F4682-I/ML — 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 PIC18F4682-I/ML (same form factor and footprint) — differing in Package, Operating Temperature, Timers, ADC, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4685-I/ML
✅ Drop-In✓ In Stock
$6.48 / Unit
View Datasheet →PIC18F4585-I/ML
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F4480-I/ML
✅ Drop-In✓ In Stock
$4.89 / Unit
View Datasheet →PIC18F4682-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4682T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4682-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard bus) |
| Maximum Clock Frequency | 40 MHz |
| Program Memory (Flash) | 80 KB (40K x 16) |
| Data RAM | 3.3 KB (3328 bytes) |
| Data EEPROM | 1 KB (1024 bytes) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, up to 11 channels |
| CAN Module | ECAN (Enhanced CAN 2.0B) |
| Communication Peripherals | EUSART, MSSP (SPI / I2C) |
| Timers | 2 x 8-bit, 3 x 16-bit |
| CCP / ECCP Modules | 2 |
| Operating Temperature Range (I grade) | -40C to +85C (industrial) |
| Package | 44-pin QFN (8x8 mm) with exposed pad |
| Mounting Type | Surface Mount |
| ICSP / ICD | Yes (In-Circuit Serial Programming / Debug) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F4682-I/ML Pin Configuration
| Pin 1 | RA2 — Digital I/O / analog input AN2 |
| Pin 2 | RA3 — Digital I/O / analog input AN3 / VREF+ |
| Pin 3 | RA4 — Digital I/O / analog input AN4 |
| Pin 4 | RA5 — Digital I/O / analog input AN5 / SS |
| Pin 5 | RA6 — Digital I/O / oscillator output |
| Pin 6 | RA7 — Digital I/O / oscillator input |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply 4.2-5.5 V |
| Pin 9 | RB0 — Digital I/O / interrupt-on-change |
| Pin 10 | RB1 — Digital I/O / interrupt-on-change |
| Pin 11 | RB2 — Digital I/O / interrupt-on-change |
| Pin 12 | RB3 — Digital I/O / interrupt-on-change |
| Pin 13 | RB4 — Digital I/O / interrupt-on-change |
| Pin 14 | RB5 — Digital I/O / interrupt-on-change / PGM |
| Pin 15 | RB6 — Digital I/O / ICD PGC |
| Pin 16 | RB7 — Digital I/O / ICD PGD |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply 4.2-5.5 V |
| Pin 19 | RC0 — Digital I/O |
| Pin 20 | RC1 — Digital I/O / CCP2 |
| Pin 21 | RC2 — Digital I/O / CCP1 / PWM |
| Pin 22 | RC3 — Digital I/O / SCL |
| Pin 23 | RC4 — Digital I/O / SDA |
| Pin 24 | RC5 — Digital I/O / SDO |
| Pin 25 | RC6 — Digital I/O / TX |
| Pin 26 | RC7 — Digital I/O / RX |
| Pin 27 | VSS — Ground reference |
| Pin 28 | VDD — Positive supply 4.2-5.5 V |
| Pin 29 | RD0 — Digital I/O / PSP data |
| Pin 30 | RD1 — Digital I/O / PSP data |
| Pin 31 | RD2 — Digital I/O / PSP data |
| Pin 32 | RD3 — Digital I/O / PSP data |
| Pin 33 | RD4 — Digital I/O / PSP data |
| Pin 34 | RD5 — Digital I/O / PSP data |
| Pin 35 | RD6 — Digital I/O / PSP data |
| Pin 36 | RD7 — Digital I/O / PSP data |
| Pin 37 | VSS — Ground reference |
| Pin 38 | VDD — Positive supply 4.2-5.5 V |
| Pin 39 | RE0 — Digital I/O / RD / AN5 |
| Pin 40 | RE1 — Digital I/O / WR / AN6 |
| Pin 41 | RE2 — Digital I/O / CS / AN7 |
| Pin 42 | RE3 — Digital I/O |
| Pin 43 | CANTX — ECAN transmit output |
| Pin 44 | CANRX — ECAN receive input |
Typical Applications
PIC18F4682-I/ML is suitable for 6 applications: Industrial CAN Sensor Nodes, Automotive Body and Comfort Electronics, Building Automation Gateways, USB-to-CAN Bridge Adapter, Embedded Motor-Control Front End, Medical Device Control Boards.
Industrial CAN Sensor Nodes
The PIC18F4682-I/ML fits industrial CAN sensor nodes because its ECAN 2.0B module, 10-bit ADC with up to 11 channels, and 40 MHz PIC18 core handle one sensor read-and-broadcast loop in well under 1 ms. With 80 KB of Flash, designers can fit a CANopen or DeviceNet stack plus application code in a single image, while the 3.3 KB RAM is enough for CAN message buffers and ADC averaging. The 44-QFN package exposes 36 I/O pins for parallel sensor buses, and the 4.2-5.5 V supply matches the 5 V rail common on industrial backplanes. ECAN hardware filtering cuts host CPU load, leaving headroom for local PID or threshold logic.
Recommended
Automotive Body and Comfort Electronics
In automotive body modules - door modules, seat controllers, HVAC panels - the PIC18F4682-I/ML provides the ECAN backbone that links the module to the vehicle CAN bus at 500 kbit/s or 1 Mbit/s. The 40 MHz core runs CAN interrupt handlers with comfortable margin while servicing local switches, lighting drivers, and LIN slaves. The 10-bit ADC with 11 channels reads seat-position potentiometers, thermistors, and current-sense shunts without an external mux. For under-dash mounting, the -40C to +85C industrial temperature range covers most cabin environments; engine-bay nodes should step up to the E grade (-40C to +125C). The 44-QFN footprint keeps the PCB small enough to fit inside a door-handle or mirror housing.
Recommended
Building Automation Gateways
The PIC18F4682-I/ML suits building-automation gateways that bridge BACnet, Modbus, or KNX sub-buses onto a CAN-based backbone. Its EUSART handles RS-485 Modbus traffic, while the MSSP runs SPI or I2C for local sensor and keypad I/O, all multiplexed with the ECAN peripheral so the gateway can speak multiple protocols in parallel. With 80 KB of Flash, a small BACnet stack plus routing logic fit in a single image. The nanoWatt idle modes drop the gateway's standby draw to single-digit microamps, important for always-on wall controllers. The 36 I/O pins comfortably support the LCD, keypad, and relay outputs that building controllers typically expose on the front panel.
Recommended
USB-to-CAN Bridge Adapter
A USB-to-CAN bridge uses the PIC18F4682-I/ML as the protocol engine that translates USB CDC frames from a host PC into ECAN frames on a CAN bus. The MSSP running in SPI mode talks to a USB-to-UART or USB-to-SPI bridge such as the MCP2200 or MCP2210, while the ECAN module handles bus arbitration at up to 1 Mbit/s. The 40 MHz core moves data through both buses without dropping frames, and the 3.3 KB RAM hosts the ECAN receive buffers plus a USB endpoint scratch area. The 44-QFN keeps the adapter PCB under 30 mm square so the bridge fits in a typical diagnostic-tool enclosure.
Recommended
Embedded Motor-Control Front End
The PIC18F4682-I/ML works as a smart front end for small brushless DC or stepper motor drives, where the ECCP module generates PWM with programmable dead-time and the ECAN module reports torque, speed, and fault status back to a master controller. The 10-bit ADC samples phase currents and back-EMF at the PWM rate, while the QEI (Quadrature Encoder Interface) tracks rotor position for closed-loop control. The 80 KB Flash stores a sensorless or sensored BLDC algorithm with lookup tables for commutation timing. The 44-QFN with exposed pad dissipates the modest heat from the I/O drivers at typical 24 V/2 A motor levels.
Recommended
Medical Device Control Boards
In Class II medical electronics such as infusion pumps, patient monitors, or diagnostic analyzers, the PIC18F4682-I/ML provides the deterministic 8-bit control that FDA-cleared designs often prefer. The ECAN module links the device to a bedside CAN backbone carrying waveform and alarm data, while the 10-bit ADC reads pressure, flow, or SpO2 sensor outputs. The 80 KB Flash stores a small RTOS plus the device's clinical protocol, and the 1 KB EEPROM holds non-volatile calibration constants that survive battery swaps. The -40C to +85C industrial temperature range covers hospital and ambulatory environments, and the 36 I/O pins drive keypads, LCDs, and buzzer/alarm outputs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4682-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4685-I/ML | PIC18F4585-I/ML | PIC18F4480-I/ML | PIC18F4682-E/ML | PIC18F4682T-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (8x8) | 44-QFN (8x8) - same | 44-QFN (8x8) - same | 44-QFN (8x8) - same | 44-QFN (8x8) - same | 44-QFN (8x8) - same |
| Program Flash | 80 KB | 96 KB | 48 KB | 16 KB | 80 KB | 80 KB |
| Data RAM | 3.3 KB | 3.3 KB | 3.3 KB | 768 B | 3.3 KB | 3.3 KB |
| Maximum Clock | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| CAN Module | ECAN 2.0B | ECAN 2.0B | ECAN 2.0B | CAN 2.0A/B (legacy) | ECAN 2.0B | ECAN 2.0B |
| ADC Resolution | 10-bit | 10-bit | 10-bit | 10-bit | 10-bit | 10-bit |
| Temperature Grade | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Extended (-40C to +125C) | Industrial (-40C to +85C) |
| Unit Price (qty 1) | USD 9.20 | USD 10.10 | USD 8.50 | USD 7.20 | USD 10.50 | USD 9.20 |
Key Differentiators
- On-chip ECAN 2.0B peripheral (vs PIC18F4585-I/ML)
- 80 KB Flash in the 44-QFN footprint (vs PIC18F4480-I/ML)
- Industrial temperature grade with E variant for hot environments (vs PIC18F4682T-I/ML)
Design Notes
The 44-QFN exposed pad is the primary ground anchor and thermal path. Per the Microchip PIC18F4682 datasheet package section, the PCB land pattern must include a 5x5 array of vias on the exposed pad, tied to the ground plane. Skipping the vias raises junction temperature by 15-20 C and degrades ADC accuracy by 1-2 LSBs because of ground bounce on the analog reference. Estimated: at 40 MHz with all 36 I/O toggling, dissipation is around 0.25 W; without the via array, theta_JA rises from ~28 C/W to ~40 C/W.
ECAN pins CANTX/CANRX (pins 43/44 on the QFN) are NOT 5 V tolerant in some configurations, and the bus requires an external MCP2551 or similar transceiver. According to the Microchip PIC18F4682 datasheet, connecting the ECAN pins directly to a CAN bus without isolation will damage the MCU on the first bus fault. Always add 120 ohm termination at both ends of the bus, and place a TVS such as PESD1CAN on the bus pins for automotive EMC compliance.
Decouple VDD with a 100 nF ceramic placed within 5 mm of each VDD pin (pins 8, 18, 28, 38). The PIC18F4682 datasheet recommends a bulk 10 uF tantalum or ceramic on the main VDD rail. Estimated: the four VDD pins together can source up to 200 mA of I/O current at 40 MHz; without local decoupling, VDD sag during I/O switching will reset the ADC mid-conversion. Connect AVSS to VSS with a single-point star ground near the MCU.
Keep ICP/ICSP pins (PGD/PGC, RB6/RB7) accessible in the final layout even if you do not plan to use them in production. The PIC18F4682 datasheet's ICSP section shows that the debugger expects direct access to these pins with no series resistors above 100 ohm. Adding an LED or buffer in series will prevent in-circuit debugging and require rework to recover programming access during development.
Compliance Information
RoHS and lead-free per Microchip product page; -I grade is industrial (-40C to +85C), not AEC-Q100 automotive; for AEC-Q100 grade choose the automotive PIC18F variants. Halogen-free status not stated in verified data.
