PIC18LF4431-I/P - 8-bit PIC18 40MHz 16KB Flash MCU | Microchip
料号： PIC18LF4431-I/P ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $6.45 | $6.45 |
| 10 | $5.82 | $58.20 |
| 100 | $5.21 | $521.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.35 | $4,350.00 |
PIC18LF4431-I/P 概述
An 8-bit microcontroller (MCU) is a programmable integrated circuit that uses an 8-bit data path, executes instructions from on-chip Flash memory, and integrates CPU, RAM, non-volatile storage, and peripherals (ADC, PWM, timers, communication) into a single chip. The PIC18LF family sits above PIC16 in Microchip's 8-bit hierarchy and is widely used where deterministic interrupt response, low power, and proven toolchains matter more than raw compute. The 'LF' suffix designates the wide-voltage variant that operates across 2.0V-5.5V, while the 'F' (non-LF) version targets 4.2V-5.5V only.
Key features include 16KB (8K x 16) Flash program memory, 768 bytes of data RAM, a 10-bit ADC with multiple channels, an enhanced CCP (Capture/Compare/PWM) module with up to 14-bit resolution for motor control, and nanoWatt Technology power management offering Sleep, Idle, and Run modes. The 40-pin PDIP package is the most legacy-friendly footprint in the PIC18 line and is preferred for prototyping, hobbyist designs, and educational platforms.
The PIC18LF4431-I/P uses Microchip's enhanced Harvard RISC architecture with 16-bit instructions, 8-bit data, and a hardware multiplier, executing up to 10 MIPS at 40 MHz. Code is fetched from Flash through a 16-bit program bus while data moves on an 8-bit bus, which together enable single-cycle instruction execution and predictable timing for interrupt-driven firmware.
Typical applications include three-phase induction motor control (BLDC, PMSM), HVAC fan and pump control, industrial automation, SMPS digital control loops, automotive body electronics (via the automotive-grade PIC18F4431-I/P sibling), and educational/development boards. The integrated high-resolution PWM and ADC are tuned specifically for closed-loop motor control firmware.
When designing with this MCU, remember that 'LF' denotes the wide-voltage variant - do not swap it for the non-LF PIC18F4431 in 3.3V-only designs. Programming is done via ICSP through PGC/PGD pins, and MPLAB X IDE plus MPLAB XC8 are the supported toolchains. ESD-sensitive pins (especially analog inputs) require series resistors and clamping.
This page synthesizes distributor pricing, drop-in alternative MPNs from the same PIC18 family, and practical design notes not consolidated in the manufacturer datasheet alone.
直接替换替代料： PIC18LF4431-I/P ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： PIC18LF4431-I/P （相同外形与封装尺寸） ——差异在于 Package, Mounting Type, I/O Pins, Core, Power-Saving Modes.
快速对比工具——选择替代料号进行并排对比：
PIC18F4431-I/P
✅ 直接替换✓ 有现货
$4.5 / 个
查看数据手册 →PIC18LF4331-I/P
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
PIC18F4331-I/PT
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$3.05 / 个
查看数据手册 →PIC18LF4539-I/P
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$6.3 / 个
查看数据手册 →PIC18F4539-I/P
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
PIC18LF442-I/PT
✅ 直接替换✓ 有现货
$5.85 / 个
查看数据手册 →PIC18LF4431-I/P 最大额定值与电气特性
| Core | PIC18 (8-bit RISC, 16-bit instructions) |
| Program Memory | 16 KB (8K x 16) Flash |
| Data RAM | 768 bytes |
| Maximum CPU Frequency | 40 MHz (10 MIPS) |
| Supply Voltage Range | 2.0 V to 5.5 V (LF wide-voltage variant) |
| I/O Pins | 34 |
| ADC | 10-bit, multi-channel |
| PWM | Enhanced CCP, up to 14-bit resolution (motor-control optimized) |
| Communication | UART, SPI, I2C |
| 工作温度 | -40 C to +85 C (Industrial) |
| 封装 | 40-pin PDIP (DIP-40) |
| 安装类型 | Through-Hole (THT) |
| MSL 等级 | Not applicable (THT) |
| RoHS 状态 | Compliant |
| Lead-Free | Yes |
| ICSP Programming | Yes (PGC/PGD) |
| Power-Saving Modes | nanoWatt Technology: Run / Idle / Sleep |
PIC18LF4431-I/P 引脚配置
| 引脚 1 | MCLR/VPP/RE3 — Master Clear (reset) / ICSP programming voltage / digital I/O RE3 |
| 引脚 2 | RA0/AN0 — Digital I/O RA0 / analog input AN0 |
| 引脚 3 | RA1/AN1 — Digital I/O RA1 / analog input AN1 |
| 引脚 4 | RA2/AN2/VREF- — Digital I/O RA2 / analog input AN2 / ADC VREF- |
| 引脚 5 | RA3/AN3/VREF+ — Digital I/O RA3 / analog input AN3 / ADC VREF+ |
| 引脚 6 | RA4/T0CKI — Digital I/O RA4 / Timer0 clock input |
| 引脚 7 | RA5/AN4/SS — Digital I/O RA5 / analog input AN4 / SPI slave select |
| 引脚 8 | RE0/RD — Digital I/O RE0 |
| 引脚 9 | RE1/WR — Digital I/O RE1 |
| 引脚 10 | RE2/CS — Digital I/O RE2 |
| 引脚 11 | VDD — Positive supply voltage (2.0-5.5 V) |
| 引脚 12 | VSS — Ground reference |
| 引脚 13 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock / digital I/O RA7 |
| 引脚 14 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / digital I/O RA6 |
| 引脚 15 | RC0/T1OSO/T13CKI — Digital I/O RC0 / Timer1 oscillator output |
| 引脚 16 | RC1/T1OSI/CCP2 — Digital I/O RC1 / Timer1 oscillator input / CCP2 |
| 引脚 17 | RC2/CCP1 — Digital I/O RC2 / CCP1 PWM output |
| 引脚 18 | RC3/SCK/SCL — Digital I/O RC3 / SPI SCK / I2C SCL |
| 引脚 19 | RD0/PSP0 — Digital I/O RD0 / parallel slave port bit 0 |
| 引脚 20 | RD1/PSP1 — Digital I/O RD1 / parallel slave port bit 1 |
| 引脚 21 | RD2/PSP2 — Digital I/O RD2 / parallel slave port bit 2 |
| 引脚 22 | RD3/PSP3 — Digital I/O RD3 / parallel slave port bit 3 |
| 引脚 23 | RC4/SDI/SDA — Digital I/O RC4 / SPI SDI / I2C SDA |
| 引脚 24 | RC5/SDO — Digital I/O RC5 / SPI SDO |
| 引脚 25 | RC6/TX/CK — Digital I/O RC6 / UART TX / UART clock |
| 引脚 26 | RC7/RX/DT — Digital I/O RC7 / UART RX / UART data |
| 引脚 27 | RD4/PSP4 — Digital I/O RD4 / parallel slave port bit 4 |
| 引脚 28 | RD5/PSP5 — Digital I/O RD5 / parallel slave port bit 5 |
| 引脚 29 | RD6/PSP6/TX2 — Digital I/O RD6 / parallel slave port bit 6 / AUSART2 TX |
| 引脚 30 | RD7/PSP7/RX2 — Digital I/O RD7 / parallel slave port bit 7 / AUSART2 RX |
| 引脚 31 | VSS — Ground reference |
| 引脚 32 | VDD — Positive supply voltage (2.0-5.5 V) |
| 引脚 33 | RB0/INT0 — Digital I/O RB0 / external interrupt 0 |
| 引脚 34 | RB1/INT1 — Digital I/O RB1 / external interrupt 1 |
| 引脚 35 | RB2/INT2 — Digital I/O RB2 / external interrupt 2 |
| 引脚 36 | RB3/INT3/CCP2 — Digital I/O RB3 / external interrupt 3 / CCP2 |
| 引脚 37 | RB4/KBI0 — Digital I/O RB4 / interrupt-on-change bit 0 |
| 引脚 38 | RB5/KBI1/PGM — Digital I/O RB5 / interrupt-on-change bit 1 / LVP programming |
| 引脚 39 | RB6/KBI2/PGC — Digital I/O RB6 / interrupt-on-change bit 2 / ICSP clock |
| 引脚 40 | RB7/KBI3/PGD — Digital I/O RB7 / interrupt-on-change bit 3 / ICSP data |
典型应用
PIC18LF4431-I/P 适用于 6 应用s: 3-Phase BLDC / PMSM Motor Control, Industrial HVAC Fan / Pump Control, Switch-Mode Power Supply (SMPS) Digital Control, Educational Microcontroller Boards, Industrial Sensor Hub / Data Logger, Automotive Body Electronics (via PIC18F4431-I/P sibling).
3-Phase BLDC / PMSM Motor Control
The PIC18LF4431-I/P is purpose-built for three-phase motor control thanks to its enhanced Power Control PWM module with up to 14-bit resolution, programmable dead-band, and dedicated fault inputs. Operating from 2.0-5.5 V lets it interface directly to 3.3 V gate drivers and 5 V analog feedback networks without level shifters. The 40 MIPS throughput and 10-bit ADC combined with on-chip comparators close a single-cycle ADC-PWM loop, delivering smooth torque at low RPM and predictable commutation in BLDC and PMSM drives. Placed as the main MCU on the inverter control board, it reads phase currents, computes space-vector modulation, and updates the three-phase duty cycle within microseconds, eliminating the need for an external DSP.
推荐
Industrial HVAC Fan / Pump Control
The PIC18LF4431-I/P fits HVAC variable-speed drives where deterministic PWM, an industrial temperature grade, and reliable 8-bit firmware matter more than raw CPU speed. Its nanoWatt Technology Sleep / Idle / Run modes drop the MCU quiescent current into the microamp range when the fan or pump idles, supporting Energy Star compliance. The 40-pin PDIP through-hole package is preferred for HVAC control boards because it tolerates thermal cycling and field service better than fine-pitch SMD. Connected to a 24 VAC rectified rail, the LF variant's 2.0 V start-up enables cold-boot operation from partially discharged bulk capacitors.
推荐
Switch-Mode Power Supply (SMPS) Digital Control
The PIC18LF4431-I/P is well suited to digital control of switch-mode power supplies, where its 40 MIPS core executes voltage-mode and average-current-mode control loops in firmware. The high-resolution PWM and ADC sample the output voltage and inductor current synchronously, while the 2.0-5.5 V supply lets the MCU share the auxiliary bias rail without an extra LDO. Implementing peak current-mode control or PFC in software removes the analog UC3842-style controller, reducing BOM count and enabling firmware-updatable compensation. With 34 I/O pins, the part also drives sync-rectifier FETs, fault indicators, and a PMBus-style telemetry interface from a single chip.
推荐
Educational Microcontroller Boards
The PIC18LF4431-I/P is widely adopted on university microcontroller courses and hobbyist dev boards thanks to its DIP-40 through-hole footprint, easy breadboarding, and forgiving 2.0-5.5 V supply. Students can program it via the ICSP pins using a PICkit 5 or PICkit 4 without a bootloader, and the 34 I/O pins leave enough headroom for keypad, LCD, and motor-control experiments. The PIC18 instruction set is well-documented and the MPLAB XC8 toolchain is free, making the part an entry point into embedded firmware development. Because the LF variant survives 3.3 V and 5 V lab rails, course kits can mix Arduino-style and 5 V legacy peripherals on the same board.
推荐
Industrial Sensor Hub / Data Logger
The PIC18LF4431-I/P handles distributed industrial sensor hubs that aggregate 4-20 mA loops, thermistors, and digital inputs in a single MCU. Its 10-bit ADC with multiple channels reads up to a dozen analog sensors, while the UART / SPI / I2C peripherals push the data to a host PLC or gateway. The 16 KB Flash holds a small RTOS or a custom scheduler, and nanoWatt modes stretch battery life on remote nodes. Wide-voltage operation tolerates long cable runs where the supply voltage drops under load, making this part a robust choice for factory-floor telemetry.
推荐
Automotive Body Electronics (via PIC18F4431-I/P sibling)
While the PIC18LF4431-I/P itself targets industrial, the automotive-qualified PIC18F4431-I/P variant shares the same die and pinout for body-electronics modules such as seat controllers, mirror adjusters, and HVAC blend doors. The 40-pin PDIP package supports hand-reworkable automotive aftermarket ECUs and pre-production prototypes. Engineers prototyping on the LF industrial part can migrate firmware to the AEC-Q100 automotive variant without changing the board. The motor-control PWM is ideal for driving small brushed DC actuators used in mirrors, doors, and HVAC dampers.
推荐
推荐产品汇总
工程参考数据： PIC18LF4431-I/P ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | PIC18F4431-I/P | PIC18LF4331-I/P | PIC18F4331-I/P | PIC18LF4539-I/P | PIC18F4539-I/P | PIC18LF442-I/P |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-40 (DIP-40) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) | PDIP-40 (same) |
| Core / Architecture | PIC18 8-bit, 16-bit instructions | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit |
| Flash Program Memory | 16 KB | 16 KB | 8 KB | 8 KB | 32 KB | 32 KB | 16 KB |
| Data RAM | 768 bytes | 768 bytes | 768 bytes | 768 bytes | 1408 bytes | 1408 bytes | 768 bytes |
| Maximum CPU Frequency | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| Supply Voltage Range | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V |
| I/O Pins | 34 | 34 | 34 | 34 | 34 | 34 | 34 |
| Motor-Control PWM | Yes (14-bit, fault inputs) | Yes (14-bit) | Yes (14-bit) | Yes (14-bit) | Yes (14-bit) | Yes (14-bit) | Standard CCP (no motor-control PWM) |
| Automotive Grade | No (Industrial) | AEC-Q100 (automotive) | No | AEC-Q100 (automotive) | No | AEC-Q100 (automotive) | No |
关键差异点
- Wide-voltage 2.0 V to 5.5 V operation （对比 PIC18F4431-I/P)
- Larger Flash than the 4331 sibling （对比 PIC18LF4331-I/P)
- Dedicated motor-control PWM module （对比 PIC18LF442-I/P)
- Industrial temperature grade and nanoWatt modes （对比 PIC18F4539-I/P)
设计说明
The PIC18LF4431-I/P accepts 2.0 V to 5.5 V on VDD, but brown-out reset (BOR) thresholds and ADC VREF behavior vary across the range. Place a 100 nF decoupling capacitor as close as possible to each VDD/VSS pin pair (the 40-pin PDIP exposes pins 11/12 and 31/32), and add a 10 uF bulk capacitor on the VDD rail to suppress motor-current dips. Estimated: at 40 MHz with all peripherals active, IDD reaches ~25 mA; nanoWatt Sleep drops this into the microamp range for battery-backed designs.
Keep analog inputs (AN0-AN4) routed away from PWM outputs and the crystal traces to minimize coupling into ADC samples. Place the ICSP connector (PGC/PGD/MCLR/VPP) on the board edge with a 4.7 kohm pull-up on MCLR so the PICkit can attach without removing the MCU. For motor-control boards, use a ground star point under the IC with separate analog and power grounds, joined only at the MCU GND pin. Keep crystal traces short and symmetric; ground the oscillator body with a guard ring.
Do not assume the PIC18LF4431-I/P and PIC18F4431-I/P are interchangeable across voltage rails - the F variant only operates from 4.2 V to 5.5 V and will not start up at 3.3 V. Always configure the Configuration bits for the oscillator mode (HS for >4 MHz crystal) before locking the code. When using the enhanced PWM module, enable the proper PWM fault input mapping or the bridge can lock on at full duty. Finally, set unused I/O pins to outputs (low) to minimize Sleep current.
合规信息
RoHS compliant per Microchip product page and DigiKey listing. The PIC18LF4431-I/P is the industrial variant; choose PIC18F4431-I/P for AEC-Q100 automotive qualification. Lead-free matte-tin finish. Conflict-minerals declaration available from Microchip on request.
