PIC18LF4321-I/P - 8-Bit MCU, 8KB Flash, 40MHz | Microchip
MPN: PIC18LF4321-I/P ✓ Hoạt độngPIC18LF4321-I/P Tóm tắt
A microcontroller (MCU) is a single-chip computer that integrates a CPU, program and data memory, and programmable I/O peripherals onto one die, enabling standalone embedded control. PIC18F devices sit in Microchip's 8-bit enhanced architecture family, between the baseline PIC16F and the 16-bit dsPIC/PIC24 families, optimized for low-power, deterministic, interrupt-driven applications such as motor control, industrial sensing, and consumer appliances. The enhanced 16-bit instruction set and 31-level hardware stack balance C-compiler friendliness with predictable real-time response.
Key features include 10-bit ADC with up to 13 input channels, two analog comparators, an Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART), two MSSP (I²C/SPI) modules, two Capture/Compare/PWM (CCP) modules plus an Enhanced CCP for motor-control PWMs, two 8-bit timers and three 16-bit timers, and a 10-bit ADC. The LF core supports software-selectable oscillator modes including INTOSC (up to 8 MHz), HS, XT, LP, EC, and PLL with x4, providing flexible clocking for low-EMI and battery-powered designs.
Typical applications include industrial control panels, white goods and major-appliance user interfaces, low-cost remote sensor nodes, HVAC thermostat control, automotive body and lighting peripherals (non-safety), USB-to-UART bridges when paired with a PIC18LF2550, and battery-powered handheld instrumentation where the 2.0 V min supply extends usable runtime from partially-depleted cells. The 40-PDIP footprint enables breadboard-friendly prototyping and reworkable through-hole assembly.
When designing with the PIC18LF4321-I/P, ensure that VDDCORE decoupling (0.1 µF + 10 µF bulk) is placed within 6 mm of the dedicated VDDCORE/VSS pairs and respect the 50-pin microcontroller ESD precautions. Designers migrating from PIC16F should budget for the larger Flash-to-RAM ratio and 16-bit instruction word when estimating code density.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho PIC18LF4321-I/P — 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 PIC18LF4321-I/P (cùng hình factor và footprint) — khác nhau ở ADC, Timers, Core Architecture, Package, Mounting Type.
PIC18F4321-I/P
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC18LF4320-I/P
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC18LF4221-I/PT
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC18LF4331-I/P
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC18LF4321-I/ML
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC18LF4321-I/P Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC18F (8-bit enhanced) |
| CPU Core | RISC 8-bit |
| Max CPU Speed | 40 MHz (10 MIPS) |
| Instruction Set | 77 instructions, 16-bit opcodes |
| Program Memory | 8 KB (4K × 16 words) Flash |
| SRAM | 512 bytes |
| EEPROM | 256 bytes |
| Operating Voltage Range | 2.0 V to 5.5 V (LF variant) |
| Khoảng nhiệt độ hoạt động | -40 °C to +85 °C (Industrial) |
| Package / Pin Count | 40-PDIP (DIP-40, through-hole) |
| Kiểu lắp đặt | Through-Hole |
| ADC | 10-bit, multi-channel |
| Timers | 2 × 8-bit + 3 × 16-bit |
| Communication Modules | EUSART, 2 × MSSP (I²C/SPI) |
| PWM Modules | 2 × CCP + 1 × ECCP |
| Analog Comparators | 2 |
| Cấp MSL | Not applicable (through-hole) |
Cấu hình chân PIC18LF4321-I/P
| Chân 1 | RA0/AN0 — I/O port A bit 0 / analog input 0 |
| Chân 2 | RA1/AN1 — I/O port A bit 1 / analog input 1 |
| Chân 3 | RA2/AN2/VREF- — I/O port A bit 2 / analog input 2 / VREF- |
| Chân 4 | RA3/AN3/VREF+ — I/O port A bit 3 / analog input 3 / VREF+ |
| Chân 5 | RA4/T0CKI — I/O port A bit 4 / Timer0 clock input |
| Chân 6 | RA5/AN4 — I/O port A bit 5 / analog input 4 |
| Chân 7 | RE0/RD/AN5 — I/O port E bit 0 / read control / analog input 5 |
| Chân 8 | RE1/WR/AN6 — I/O port E bit 1 / write control / analog input 6 |
| Chân 9 | RE2/CS/AN7 — I/O port E bit 2 / chip select / analog input 7 |
| Chân 10 | VDD — Main power supply |
| Chân 11 | VSS — Ground reference |
| Chân 12 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock in |
| Chân 13 | OSC2/CLKO/RA6 — Crystal oscillator output / clock out |
| Chân 14 | RC0/T1OSO/T13CKI — I/O port C bit 0 / Timer1 oscillator output / Timer1 clock |
| Chân 15 | RC1/T1OSI/CCP2 — I/O port C bit 1 / Timer1 oscillator input / CCP2 output |
| Chân 16 | RC2/CCP1 — I/O port C bit 2 / CCP1 output |
| Chân 17 | RC3/SCK/SCL — I/O port C bit 3 / SPI clock / I²C clock |
| Chân 18 | RC4/SDI/SDA — I/O port C bit 4 / SPI data in / I²C data |
| Chân 19 | RC5/SDO — I/O port C bit 5 / SPI data out |
| Chân 20 | RC6/TX/CK — I/O port C bit 6 / EUSART TX / EUSART clock |
| Chân 21 | RC7/RX/DT — I/O port C bit 7 / EUSART RX / EUSART data |
| Chân 22 | RB0/INT0 — I/O port B bit 0 / external interrupt 0 |
| Chân 23 | RB1/INT1 — I/O port B bit 1 / external interrupt 1 |
| Chân 24 | RB2/INT2 — I/O port B bit 2 / external interrupt 2 |
| Chân 25 | RB3/CCP2 — I/O port B bit 3 / CCP2 |
| Chân 26 | RB4 — I/O port B bit 4 |
| Chân 27 | RB5 — I/O port B bit 5 |
| Chân 28 | RB6/PGC — I/O port B bit 6 / ICSP clock |
| Chân 29 | RB7/PGD — I/O port B bit 7 / ICSP data |
| Chân 30 | VDD — Main power supply |
| Chân 31 | VSS — Ground reference |
| Chân 32 | RD0 — I/O port D bit 0 |
| Chân 33 | RD1 — I/O port D bit 1 |
| Chân 34 | RD2 — I/O port D bit 2 |
| Chân 35 | RD3 — I/O port D bit 3 |
| Chân 36 | RD4 — I/O port D bit 4 |
| Chân 37 | RD5 — I/O port D bit 5 |
| Chân 38 | RD6 — I/O port D bit 6 |
| Chân 39 | RD7 — I/O port D bit 7 |
| Chân 40 | AVDD — Analog power supply |
Ứng dụng tiêu biểu
PIC18LF4321-I/P phù hợp cho 6 Áp dụngs: Industrial Control Panels, White Goods / Major Appliances, HVAC Thermostat Control, Battery-Powered Sensor Node, USB-to-UART Bridge Module, Automotive Body/Lighting Controller (Non-Safety).
Industrial Control Panels
The PIC18LF4321-I/P fits industrial control panels because its 2.0 V to 5.5 V supply range tolerates wide 24 V-bus-derived rails after regulation, while the 10-bit ADC with dedicated analog reference reads 4-20 mA current loop signals from field transmitters with 1 mV resolution. Two CCP modules plus ECCP drive relay coils and contactor coils directly via optocoupled transistor interfaces, and the EUSART links to RS-485 transceivers for Modbus RTU communication. The 40-PDIP package supports through-hole PCB assembly that withstands vibration in factory-floor enclosures better than surface-mount parts, and the 77-instruction RISC core plus 8 KB Flash accommodates complete PID loop and Modbus stack implementations without external memory.
Được đề xuất
White Goods / Major Appliances
Consumer washing machines, dishwashers, and refrigerators fit the PIC18LF4321-I/P because the 8 KB Flash stores motor-control PID tables and user-interface state machines, while the ECCP generates 4-channel PWM with programmable dead-band for driving washing-machine drum or compressor BLDC motors. The 2.0 V to 5.5 V supply range and 31 kHz low-power oscillator let the MCU monitor door switches and pushbutton presses at average current below 30 µA in standby mode, extending ENERGY STAR compliance. The integrated 10-bit ADC reads thermistor divider and water-level sensors simultaneously with sample-and-hold scanning at the 40 MHz core rate, achieving a one-second ADC throughput that satisfies appliance controller response requirements.
Được đề xuất
HVAC Thermostat Control
Wall-mounted HVAC thermostats fit the PIC18LF4321-I/P because the LF variant's 2.0 V minimum supply matches common 24 VAC transformer-derived regulated rails with extra headroom, while the 40-MIPS performance runs the PI loop at 1 Hz without CPU saturation. The integrated 10-bit ADC multiplexes four 10 kΩ NTC thermistor dividers for indoor, outdoor, supply-air, and humidity probe, while the EUSART links the controller to Wi-Fi or sub-GHz wireless module over UART for smartphone integration. The 40-PDIP through-hole format allows large-pad solder-friendly rework during field service, while the -40 °C to +85 °C industrial grade supports unheated attic enclosure environments.
Được đề xuất
Battery-Powered Sensor Node
Wireless IoT sensor nodes operating from a single-cell Li-ion or alkaline pair fit the PIC18LF4321-I/P because the LF supply range extends usable runtime down to 2.0 V when the cell is partially depleted, and the 31 kHz INTOSC consumes only microamp current in Sleep mode while still waking the MCU on UART activity or ADC-comparator interrupt. The 8 KB Flash stores MB-connected Zigbee or LoRa register configurations and 8-bit trimmed ADC coefficients, while the 256-byte EEPROM retains calibration constants across battery replacement. The EUSART plus MSSP drives a LoRa transceiver and a SPI flash simultaneously with deterministic interrupt latency, and the 40-PDIP footprint simplifies robotic assembly on legacy through-hole sensor boards.
Được đề xuất
USB-to-UART Bridge Module
USB-to-UART bridge modules using a PIC18LF2550 companion with the PIC18LF4321-I/P for monitoring fit the part family because the LF supply matches 3.3 V USB regulated rails and the 40-pin DIP exposes the full set of peripheral functions for serial protocol debugging. When used as a debug sink, the PIC18LF4321-I/P receives bytes from the PIC18LF2550's UART, decodes them with the EUSART DMA-style interrupt service, and reflects status on its 5 timers, while the SPI MSSP drives an SSD1306 OLED display at 4 MHz without CPU overhead. The 8 KB Flash holds small command parsers and 16-bit cyclic-redundancy-check validators for industrial UART protocols like BACnet or Modbus ASCII.
Được đề xuất
Automotive Body/Lighting Controller (Non-Safety)
Non-safety automotive body modules such as interior lighting, mirror adjustment, and seat-position memory fit the PIC18LF4321-I/P because the industrial -40 °C to +85 °C range withstands cabin temperatures, while the LF supply operates directly from a 5 V regulated body-control rail. The ECCP provides PWM dimming for LED interior and instrument-cluster illumination, and the 10-bit ADC multiplexes photodiode sense inputs for auto-headlamp and twilight detection. The EUSART connects the module to a CAN-MCP2551 CAN bridge chip via SPI-over-MSSP at 1 Mb/s, while the 40-PDIP package is preferred for low-volume body-module prototypes sold in garages rather than OEM production lines.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC18LF4321-I/P — 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 | PIC18F4321-I/P | PIC18LF4320-I/P | PIC18LF4331-I/P | PIC18LF4221-I/P | PIC18LF4321-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-PDIP (through-hole) | 40-PDIP (through-hole) | 40-PDIP (through-hole) | 40-PDIP (through-hole) | 40-PDIP (through-hole) | 44-QFN (SMD) |
| Operating Voltage Range | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Max CPU Frequency | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) |
| ADC Resolution | 10-bit | 10-bit | 10-bit | 12-bit | 10-bit | 10-bit |
| ECCP Module | Yes (1× ECCP + 2× CCP) | Yes (1× ECCP + 2× CCP) | Yes (1× ECCP + 2× CCP) | Yes (motor-control optimized) | Yes (1× ECCP + 2× CCP) | Yes (1× ECCP + 2× CCP) |
Bảo phân biệt quan trọng
- Low-voltage 2.0 V minimum supply (vsPIC18F4321-I/P)
- Enhanced CCP module for motor control (vsPIC18F4331-I/P)
- Through-hole 40-PDIP form factor (vsPIC18LF4321-I/ML)
Ghi chú thiết kế
Place a 0.1 µF ceramic decoupling capacitor within 6 mm of every VDD/VSS pair, plus a 10 µF bulk tantalum or aluminum-polymer capacitor on the main VDD rail. The PIC18LF4321-I/P can operate from 2.0 V to 5.5 V, so for 5 V systems use a common MCP1700 or 7805 LDO. For battery-powered 2-3 cell packs, the LF variant extends usable runtime by 30-40% versus the standard PIC18F4321, which requires 4.2 V minimum to start up.
When migrating from PIC16F to PIC18LF4321-I/P, do not assume Flash page size is identical: PIC18 uses 64-word (128-byte) Flash erase pages versus 2 KB on PIC16F1xx. Also, the configuration bits register is at address 0x300000, not at the end of Flash as on PIC16F. Always run the FRM 'Migration to PIC18F' guidelines when porting C code; firmware compiled for PIC16F873 will not directly run on PIC18F4321. The Analog Comparator CVREF reference voltage at FVR is ~1.2 V, not 2.5 V as on PIC18F older silicon revisions.
The 40-PDIP package leaves 0.1 inch pin pitch which is breadboard-friendly but requires through-hole PCB mounting. Route analog signals RA0-RA5 away from digital switching traces like RC0-RC7 (EUSART / MSSP) to minimize ADC-induced noise; add a guard ring around AVdd and place the FVR bypass cap adjacent to pin 11 (VSS). For high-impedance sensors, enable the ADC's acquisition time extension in ADCON1 to 4 Tad or higher to avoid sampling-capacitor charge sharing errors.
Thông tin tuân thủ
RoHS compliance confirmed by Microchip product page; industrial temperature rating (I-suffix) supports -40 °C to +85 °C; not AEC-Q100 qualified - for automotive safety-critical use, select PIC18F4321-I/PT automotive-grade variant instead.
