PIC18F4685T-I/PT - 8-Bit MCU, 96KB Flash, ECAN, 44-TQFP | Microchip
MPN: PIC18F4685T-I/PT ✓ Hoạt độngPIC18F4685T-I/PT Tóm tắt
A microcontroller (MCU) is a single-chip computer that contains a processor core, program memory, data memory, and peripherals. The PIC18F4685 belongs to the PIC18F enhanced family, which sits in the broader 8-bit PIC hierarchy (PIC10/12/16/18) and ultimately under the embedded controller branch of semiconductor products. The PIC18F4685T-I/PT adds Enhanced CAN, 10-bit ADC with up to 11 channels, nanoWatt power management, and a 16-bit capture/compare/PWM module, making it well suited to mid-range embedded control.
Key features of the PIC18F4685T-I/PT include 36 digital I/O pins, 10-bit ADC with 11 input channels, two Enhanced USART modules, MSSP (SPI/I2C), two Enhanced Capture/Compare/PWM (ECCP) peripherals, 10 MIPS throughput at 40 MHz, and nanoWatt power-saving modes. The ECAN module supports CAN 2.0B active with multiple receive/transmit buffers. Self-programmability under software control, Flash program memory with 100K erase/write cycles typical, and a 10-year data retention rating simplify in-field firmware updates.
Architecturally, the PIC18F4685 uses a Harvard RISC core with a modified instruction set that retains compatibility with earlier PIC16 code while adding 16-bit instructions, indexed addressing, and a linear data memory space up to 4 KB. The on-chip ECAN peripheral implements the CAN 2.0B protocol in hardware, offloading bit timing, acceptance filtering, and message buffering from the CPU and enabling real-time deterministic networking at 1 Mbit/s.
Typical applications include industrial automation with CAN-bus networking, automotive body and powertrain ECUs, building automation, HVAC controllers, medical instrumentation with CAN connectivity, sensor aggregation nodes, and CAN-to-UART/SPI bridges. The wide -40 C to +85 C industrial temperature range and nanoWatt sleep modes support always-on battery-powered designs.
When designing with this part, observe Microchip's recommended decoupling: 0.1 F ceramic on each VDD pin and bulk capacitance near the IC. The ECAN bus requires a CAN transceiver such as the MCP2551 and proper 120-ohm termination. For firmware development, use MPLAB X IDE with the XC8 compiler and the PICkit 5 or ICD 4 in-circuit debugger.
This page synthesizes distributor pricing, drop-in alternatives drawn from Microchip's PIC18F family, and practical design notes not found in the manufacturer datasheet alone, giving engineers a single reference for selecting, sourcing, and validating the PIC18F4685T-I/PT for new designs or legacy migrations.
Bộ thay thế dễ dàng lắp đặt cho PIC18F4685T-I/PT — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với PIC18F4685T-I/PT (cùng hình factor và footprint) — khác nhau ở Package, ADC, Program Memory (Flash), Operating Temperature, Core Architecture.
PIC18F4685-I/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC18F4682-I/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →DSPIC33EP512MC806-E/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC18F4585-I/PT
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC18F46K22-I/PT
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC18F4685T-I/PT Tỷ lệ tối đa & tính chất điện
| Family | PIC18F4xxx |
| Core | 8-bit PIC RISC (Harvard) |
| Program Memory | 96 KB (48K x 16) Flash |
| RAM | 3.25 KB (3328 bytes) |
| EEPROM | 1 KB |
| Maximum Clock Speed | 40 MHz |
| Instruction Throughput | 10 MIPS |
| Điện áp cung cấp | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, 11 channels |
| CAN Module | ECAN 2.0B active |
| UART | 2x Enhanced USART |
| SPI | 1x MSSP (SPI/I2C) |
| PWM | 2x ECCP + 1x CCP |
| Nhiệt độ hoạt động | -40 C to +85 C (Industrial) |
| Hộp | 44-pin TQFP (10x10 mm) |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 3 (168 hours) |
| Trạng thái RoHS | Compliant |
| Lead-Free | Yes |
Cấu hình chân PIC18F4685T-I/PT
| Chân 1 | RC2/CCP1 — Digital I/O / Capture-Compare-PWM output 1 |
| Chân 2 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Chân 3 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Chân 4 | RC5/SDO — Digital I/O / SPI data out |
| Chân 5 | RC6/TX1/CK1 — Digital I/O / USART1 TX / USART1 clock |
| Chân 6 | RC7/RX1/DT1 — Digital I/O / USART1 RX / USART1 data |
| Chân 7 | RD4/ECCP1/P1A — Digital I/O / Enhanced CCP1 / PWM output |
| Chân 8 | RD5/P1B — Digital I/O / PWM output 1B |
| Chân 9 | RD6/P1C — Digital I/O / PWM output 1C |
| Chân 10 | RD7/P1D — Digital I/O / PWM output 1D |
| Chân 11 | VSS — Ground reference |
| Chân 12 | VDD — Positive supply 4.2 V to 5.5 V |
| Chân 13 | OSC1/RA7 — Crystal input or digital I/O |
| Chân 14 | OSC2/RA6 — Crystal output or digital I/O |
| Chân 15 | RC0/T1OSO — Digital I/O / Timer1 oscillator output |
| Chân 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 |
| Chân 17 | RB0/INT0 — Digital I/O / External interrupt 0 |
| Chân 18 | RB1/INT1 — Digital I/O / External interrupt 1 |
| Chân 19 | RB2/INT2 — Digital I/O / External interrupt 2 |
| Chân 20 | RB3/INT3 — Digital I/O / External interrupt 3 |
| Chân 21 | RB4/KBI0 — Digital I/O / Keyboard interrupt 0 |
| Chân 22 | RB5/KBI1 — Digital I/O / Keyboard interrupt 1 |
| Chân 23 | RB6/KBI2/PGC — Digital I/O / Keyboard interrupt 2 / ICSP clock |
| Chân 24 | RB7/KBI3/PGD — Digital I/O / Keyboard interrupt 3 / ICSP data |
| Chân 25 | MCLR — Master clear reset (active low) |
| Chân 26 | RA0/AN0 — Digital I/O / ADC input 0 |
| Chân 27 | RA1/AN1 — Digital I/O / ADC input 1 |
| Chân 28 | RA2/AN2/VREF- — Digital I/O / ADC input 2 / ADC reference low |
| Chân 29 | RA3/AN3/VREF+ — Digital I/O / ADC input 3 / ADC reference high |
| Chân 30 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Chân 31 | RA5/AN4 — Digital I/O / ADC input 4 |
| Chân 32 | VSS — Ground reference |
| Chân 33 | VDD — Positive supply 4.2 V to 5.5 V |
| Chân 34 | CANTX/RC2 — CAN transmit (shared with digital I/O) |
| Chân 35 | CANRX/RC3 — CAN receive (shared with digital I/O) |
| Chân 36 | RE0/RD — Digital I/O / Parallel port read |
| Chân 37 | RE1/WR — Digital I/O / Parallel port write |
| Chân 38 | RE2/CS — Digital I/O / Parallel port chip select |
| Chân 39 | RD0 — Digital I/O port D bit 0 |
| Chân 40 | RD1 — Digital I/O port D bit 1 |
| Chân 41 | RD2 — Digital I/O port D bit 2 |
| Chân 42 | RD3 — Digital I/O port D bit 3 |
| Chân 43 | AVSS — Analog ground reference |
| Chân 44 | AVDD — Analog positive supply |
Ứng dụng tiêu biểu
PIC18F4685T-I/PT phù hợp cho 7 Áp dụngs: Industrial CAN-bus Automation, Automotive Body and Powertrain ECU, HVAC and Building Automation Controller, Medical Instrument Sensor Hub, Sensor Aggregation and Gateway Node, Industrial Motor Control, Embedded Data Logger.
Industrial CAN-bus Automation
The PIC18F4685T-I/PT is purpose-built for industrial CAN 2.0B networks that demand deterministic real-time communication. Its integrated ECAN module supports up to 1 Mbit/s with hardware acceptance filtering, while the 10 MIPS core handles both the application stack and the CANOpen or DeviceNet protocol. The 96 KB Flash accommodates full CANOpen stack libraries with room to spare, and 3.25 KB RAM covers receive buffer pools plus application scratch. Industrial temperature operation from -40 C to +85 C supports factory-floor deployment.
Được đề xuất
Automotive Body and Powertrain ECU
The PIC18F4685T-I/PT integrates the ECAN controller, 10-bit ADC with 11 channels, ECCP PWM, and 36 I/O, all needed for body controllers, climate modules, and sensor interface ECUs. Its 16-bit ECCP modules generate precise PWM for motor and valve control, while the dual USARTs bridge LIN or K-line diagnostics. With 96 KB Flash and self-programmability, OTA-style firmware updates are possible in fielded vehicles. Pair with an MCP2551 transceiver for the physical bus.
Được đề xuất
HVAC and Building Automation Controller
In HVAC and building automation, the PIC18F4685T-I/PT aggregates data from temperature, humidity, and air-quality sensors over its 10-bit ADC and communicates to higher-level BMS backbones via ECAN. Its 36 I/O drive relays, triacs, and 7-segment displays directly. The nanoWatt power-saving modes reduce standby consumption below 1 uA in idle states, supporting always-on nodes. Wide 4.2 V to 5.5 V supply allows direct 5 V industrial bus powering.
Được đề xuất
Medical Instrument Sensor Hub
The PIC18F4685T-I/PT serves as a low-cost sensor aggregation hub in medical instrumentation, capturing data from multiple physiological sensors via its 11-channel ADC and forwarding aggregated packets over CAN to a host controller. Its 3.25 KB RAM supports buffer management for time-series streams, while 96 KB Flash hosts proprietary signal-processing routines. The ECAN module isolates safety-critical host from peripheral noise, and the -40 C to +85 C range supports clinical environments.
Được đề xuất
Sensor Aggregation and Gateway Node
The PIC18F4685T-I/PT acts as a CAN-to-UART/SPI gateway that aggregates sensor data and bridges to upstream processors. Its dual Enhanced USARTs support LIN, RS-485, or K-line, while MSSP provides SPI or I2C master to local peripherals. The 96 KB Flash stores routing tables and protocol converters, and 3.25 KB RAM buffers inter-bus traffic. ECAN handles real-time bus arbitration at 1 Mbit/s without CPU intervention.
Được đề xuất
Industrial Motor Control
The PIC18F4685T-I/PT drives BLDC and stepper motors with its two Enhanced Capture/Compare/PWM modules, which support center-aligned, complementary, and dead-band-controlled outputs. The 40 MHz core and 10 MIPS throughput compute PI control loops with sub-microsecond latency, while the 10-bit ADC samples current shunts for closed-loop feedback. The 36 I/O handle direction control, fault inputs, and encoder feedback, and ECAN carries status messages to a centralized controller.
Được đề xuất
Embedded Data Logger
The PIC18F4685T-I/PT functions as a self-contained data logger with 1 KB internal EEPROM and SPI/I2C master ports to external Flash or FRAM. Its 96 KB Flash stores the logger firmware and 3.25 KB RAM implements ring buffers, while 36 I/O read sensors and digital inputs. The ECAN interface time-stamps events from a central network. nanoWatt sleep modes and RTC operation enable multi-year battery life on unattended loggers in remote sites.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC18F4685T-I/PT — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | PIC18F4685-I/PT | PIC18F4682-I/PT | DSPIC33EP512MC806-E/PT | PIC18F4585-I/PT | PIC18F46K22-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10) | 44-TQFP (10x10) | 44-TQFP (10x10) | 64-TQFP (10x10) | 44-TQFP (10x10) | 44-TQFP (10x10) |
| Program Memory | 96 KB Flash | 96 KB Flash | 80 KB Flash | 512 KB Flash | 48 KB Flash | 64 KB Flash |
| RAM | 3.25 KB | 3.25 KB | 3.25 KB | 48 KB | 3.25 KB | 3.86 KB |
| Max Clock | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 70 MHz / 70 MIPS | 40 MHz / 10 MIPS | 64 MHz / 16 MIPS |
| CAN Module | ECAN 2.0B active | ECAN 2.0B active | ECAN 2.0B active | ECAN 2.0B active | ECAN 2.0B active | None |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 3.0 V to 3.6 V | 4.2 V to 5.5 V | 1.8 V to 5.5 V |
| ADC | 10-bit, 11 ch | 10-bit, 11 ch | 10-bit, 11 ch | 10/12-bit, 24 ch | 10-bit, 11 ch | 10-bit, 30 ch |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C |
Bảo phân biệt quan trọng
- Tape-and-reel packaging for high-volume pick-and-place assembly (vsPIC18F4685-I/PT)
- 96 KB Flash supports CANOpen and DeviceNet stacks (vsPIC18F4585-I/PT)
- Lower-cost alternative with same peripheral set (vsPIC18F4682-I/PT)
Ghi chú thiết kế
Place a 0.1 uF ceramic decoupling capacitor as close as possible to each VDD pin (pins 12, 33) and a bulk capacitor (10 uF tantalum or 4.7 uF ceramic) on the analog AVDD pin (44) with corresponding AVSS (43) ground. Per Microchip's PIC18F4685 datasheet, inadequate decoupling on AVDD causes ADC reference noise and degrades conversion accuracy by several LSBs. nanoWatt sleep modes drop supply current below 1 uA but require both decoupling networks to remain in place during wake transitions.
Route the ECAN CANTX/CANRX signals as a differential pair with 100-ohm characteristic impedance, length-matched within 5 mm, and isolated from digital switching traces. According to the Microchip PIC18F2682/2685/4682/4685 datasheet ECAN section, the CANTX/CANRX pins are shared with RC2/RC3, so assign these I/O carefully to avoid conflicts with SPI or I2C peripherals on the same ports. Place the MCP2551 transceiver within 50 mm of the MCU for signal integrity.
The PIC18F4685T-I/PT in 44-TQFP at 40 MHz consumes roughly 25 mA typical active current and 1-2 uA in sleep. Estimated: at ambient 85 C and active 25 mA from 5 V, junction-to-ambient thermal resistance for 44-TQFP is approximately 50 C/W, yielding a 6 C rise well within the -40 C to +125 C operating junction envelope. No special thermal management is required for typical embedded designs.
When migrating firmware from PIC18F4685 to PIC18F4682, ensure all Flash pages remain below the 80 KB address boundary; code that compiles above 0x14000 on the 4685 will overflow on the 4682 and silently corrupt the linker output. According to Microchip, the device ID registers must also be polled at startup to confirm the target MCU, especially on production boards where either variant may be populated.
For ICSP programming on pins 23 (PGC) and 24 (PGD), Microchip recommends 4.7 kohm pull-up resistors on PGD and PGC to keep them defined during reset and prevent unintentional entry into programming mode. According to Microchip's ICSP application note, omit these pull-ups only when an external programmer drives the bus; otherwise floating PGD/PGC may cause transient reset events in noisy industrial environments.
Thông tin tuân thủ
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - choose dsPIC33EP512MC806-E/PT for automotive Grade-1 environments. Lead-free T&R packaging only.