PIC18F4431-E/ML - 8-bit 40MHz MCU, 16KB Flash, QFN-44 | Microchip
MPN： PIC18F4431-E/ML ✓ 啟用中PIC18F4431-E/ML 概覽
What is a PIC18F microcontroller? The PIC18F is a high-performance 8-bit RISC architecture family from Microchip Technology, belonging to the broader microcontroller > embedded MCU > semiconductor hierarchy. PIC18F parts use a Harvard architecture with separate program and data buses, an instruction set optimized for C code generation, and Microchip's nanoWatt power-management technology for low-power applications.
Key features of the PIC18F4431 include four enhanced PWM channels with up to 14-bit resolution, a 10-bit A/D converter with up to 9 input channels, a 40 MHz oscillator (10 MHz internal RC), nanoWatt power management with idle and sleep modes, and 34 digital I/O pins. The device integrates a 10-bit ADC, two analog comparators, a USART, an SPI/I2C-compatible MSSP module, and a 16-bit timer/counter with capture/compare.
The PIC18F4431 implements Microchip's enhanced flash cell technology, supporting self-programming and ICD (in-circuit debug) via two I/O pins, eliminating the need for an external programmer socket. The 44-pin QFN package with exposed pad offers excellent thermal performance for the extended industrial temperature range, and the wide 2.0V to 5.5V VDD range enables both 3.3V and 5V system designs.
Typical applications include three-phase AC induction motor control, brushless DC motor drives, switched-mode power supply control, uninterruptible power supplies, and precision industrial automation. The combination of 14-bit PWM resolution and 10-bit ADC makes it well suited for closed-loop digital control loops where resolution and dynamic range are critical.
When designing with the PIC18F4431, ensure the exposed thermal pad is soldered to the PCB ground plane for proper heat dissipation, and place the decoupling capacitor (100 nF) within 3 mm of each VDD pin pair. Use MPLAB X IDE with XC8 compiler for development; ICD debugging requires only two pins and no external emulator hardware.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on the manufacturer datasheet. All electrical characteristics are extracted from the Microchip PIC18F2331/2431/4331/4431 datasheet family and verified against DigiKey/Mouser stock records as of 2026-09-27.
直接替換替代品，適用於 PIC18F4431-E/ML — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PIC18F4431-E/ML （相同外形與佔位） — 差異在於 ADC, Package, I/O Pins, Operating Temperature, Program Memory (Flash).
PIC18F4431-I/ML
✅ 直接替換聯絡詢價
查看資料表 →PIC18F4331-I/ML
✅ 直接替換聯絡詢價
查看資料表 →PIC18F46K20-I/ML
✅ 直接替換聯絡詢價
查看資料表 →PIC18LF44K22-I/ML
✅ 直接替換聯絡詢價
查看資料表 →PIC18F4431-E/ML 最大額定值與電氣特性
| Core Architecture | PIC18F, 8-bit Harvard RISC |
| CPU Speed | 40 MHz (16 MIPS) |
| Instruction Cycle | 200 ns @ 20 MHz, 100 ns @ 40 MHz |
| Program Memory (Flash) | 16 KB (8K x 16) |
| RAM | 768 bytes |
| I/O Pins | 34 |
| ADC | 10-bit, up to 9 channels |
| PWM Channels | 4 (14-bit enhanced) |
| Timers | 1x 16-bit, 3x 8-bit |
| Communication | 1x USART, 1x MSSP (SPI/I2C) |
| Comparators | 2x analog |
| Operating Voltage (VDD) | 2.0 V to 5.5 V |
| 工作溫度 | -40 C to +125 C (Extended, -E suffix) |
| 封裝 | 44-pin QFN (8x8 mm) with exposed pad |
| 安裝類型 | Surface Mount (QFN) |
| MSL 等級 | 3 |
| Lead-Free / RoHS | Lead-free matte-tin, RoHS compliant |
| In-Circuit Debug | Yes (ICD via PGC/PGD) |
PIC18F4431-E/ML 44-pin qfn (8x8 mm) with exposed pad 腳位配置指南
PIC18F4431-E/ML（44-pin qfn (8x8 mm) with exposed pad 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： PIC18F4431-E/ML.
請參閱 資料表 以查看完整腳位配置。
典型應用
PIC18F4431-E/ML 適用於 6 應用s: Three-Phase AC Induction Motor VFD, Brushless DC Motor Drive, Switched-Mode Power Supply (SMPS) Control, Uninterruptible Power Supply (UPS) Controller, Industrial Sensor Signal Conditioner, HID and LED Lighting Ballast.
Three-Phase AC Induction Motor VFD
The PIC18F4431-E/ML is purpose-built for three-phase AC induction motor variable-frequency drives. Its four 14-bit enhanced PWM channels deliver complementary outputs with programmable dead-band to drive a 3-phase IGBT inverter bridge, while the dedicated FLTA pin provides hardware shutdown within 200 ns of a fault event. The 10-bit ADC with 9 input channels simultaneously samples two shunt currents plus DC bus voltage for sensorless or closed-loop vector control. Compared with the PIC18F46K20, the PIC18F4431-E/ML has sufficient 16 KB flash for typical VFD scalar V/Hz firmware while maintaining industrial -40C to +125C qualification for outdoor cabinet installations. Placement: MCU sits between the gate-driver and the control-panel interface; rated extended temperature tolerates inverter heatsink proximity.
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Brushless DC Motor Drive
The PIC18F4431-E/ML drives BLDC and PMSM motors in 1 HP to 5 HP applications such as appliance compressors, electric pumps, and HVAC blowers. The 14-bit PWM resolution enables sinusoidal commutation with <0.025% duty-cycle step, allowing smooth torque at low RPM. The dedicated 16-bit Timer1 with capture input supports Hall-sensor or back-EMF zero-crossing detection for sensorless rotor position estimation. Operating from 2.0V to 5.5V, the same hardware can run from a 3.3V logic rail in battery-powered tools or from 5V in mains-powered industrial drives. The 44-pin QFN exposed pad delivers theta-JA approximately 28 C/W, sufficient for the extended -40C to +125C automotive and industrial environment without forced-air cooling.
推薦
Switched-Mode Power Supply (SMPS) Control
The PIC18F4431-E/ML serves as a digital controller for digitally-controlled SMPS in telecom and server applications. Its 40 MHz core executes voltage-mode and peak-current-mode control loops with sub-microsecond resolution, while the 14-bit PWM with 100 ns granularity drives the power-stage MOSFET or PFC switch. The 10-bit ADC with dedicated sampling channel pairs with the analog comparators to implement cycle-by-cycle current limiting without CPU intervention. Compared with dsPIC33F parts, the PIC18F4431-E/ML offers adequate performance for single-loop PFC and forward converter topologies at lower cost. The 16 KB flash accommodates look-up tables for PFC harmonic compensation and soft-start profiles. VDD range 2.0V to 5.5V allows direct operation from auxiliary bias supplies.
推薦
Uninterruptible Power Supply (UPS) Controller
The PIC18F4431-E/ML forms the heart of small-to-medium UPS units (300 VA to 3 kVA). Its 4 PWM channels drive the inverter and PFC stages, while 34 I/O pins handle battery monitoring, AC mains sensing, relay control, and the front-panel user interface. The 10-bit ADC with 9 channels samples battery voltage, charge current, AC mains voltage, and inverter output current simultaneously for state-of-charge calculation. The extended -40C to +125C temperature grade supports outdoor telecom cabinet installations. The 768-byte RAM holds battery-model state variables and RMS calculation buffers; the 16 KB flash stores the inverter control firmware and Modbus communication stack. The 44-pin QFN exposed pad simplifies thermal design in enclosed UPS chassis.
推薦
Industrial Sensor Signal Conditioner
The PIC18F4431-E/ML conditions signals from industrial 4-20 mA loop-powered sensors, strain gauges, and thermocouples. Its 10-bit ADC with 9 channels supports simultaneous multi-sensor acquisition, while the 14-bit PWM outputs drive 0-10V analog output stages for actuator control. The MSSP peripheral interfaces to SPI thermocouple amplifiers and I2C digital temperature sensors, allowing the MCU to aggregate mixed-signal inputs. Operating from 2.0V to 5.5V enables both loop-powered (4 mA at 24V) and self-powered (24V bus) installations. The extended temperature grade accommodates factory-floor ambient up to +125C. Compared with the PIC18F46K20 family, the 16 KB flash of the PIC18F4431-E/ML accommodates typical linearization tables for 8 thermocouple types.
推薦
HID and LED Lighting Ballast
The PIC18F4431-E/ML drives high-intensity-discharge (HID) and high-power LED lighting ballasts. Its 4 PWM channels with 14-bit resolution enable precise dimming curves and color-temperature mixing in tunable-white LED fixtures, while the high-speed 10-bit ADC monitors LED current for closed-loop brightness regulation. The extended -40C to +125C temperature grade is essential for outdoor luminaire installations where ambient reaches +85C under direct sun. The 16 KB flash stores DMX-512 or DALI protocol stacks and per-channel calibration data; the 768-byte RAM handles smooth fade transitions. The 44-pin QFN exposed pad simplifies thermal integration with the luminaire heatsink, achieving theta-JA around 28 C/W for reliable operation in enclosed fixtures.
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推薦產品摘要
工程參考資料，適用於 PIC18F4431-E/ML — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | PIC18F4431-I/ML | PIC18F4331-I/ML | PIC18F46K20-I/ML | PIC18LF44K22-I/ML |
|---|---|---|---|---|---|
| Brand | 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 |
| Flash Memory | 16 KB | 16 KB | 8 KB (-50%) | 64 KB (+300%) | 16 KB |
| RAM | 768 bytes | 768 bytes | 768 bytes | 3896 bytes (+407%) | 1536 bytes (+100%) |
| CPU Speed | 40 MHz (16 MIPS) | 40 MHz | 40 MHz | 64 MHz (+60%) | 64 MHz (+60%) |
| Operating Temperature | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| PWM Channels | 4x 14-bit enhanced | 4x 14-bit enhanced | 4x 14-bit enhanced | 4x 10-bit (CCP/ECCP) | 4x 10-bit (CCP/ECCP) |
| ADC | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 11 channels | 10-bit, 28 channels |
| I/O Pins | 34 | 34 | 34 | 36 (+2) | 36 (+2) |
主要差異化特點
- Extended -40C to +125C temperature grade standard (對比PIC18F4431-I/ML)
- Larger 16 KB flash than PIC18F4331 sibling (對比PIC18F4331-I/ML)
- 4x 14-bit enhanced PWM with dedicated fault input (對比PIC18F46K20-I/ML)
設計說明
Estimated: The 44-pin QFN exposed thermal pad delivers theta-JA approximately 28 C/W when soldered to a 1-square-inch copper ground plane on a 4-layer PCB. At maximum ambient +125C and 40 MHz active CPU drawing 25 mA, junction temperature rise is approximately 0.7C above ambient - well within the +150C absolute maximum. For best results, connect the exposed pad to the ground plane using 9 thermal vias (0.3 mm drill, 0.5 mm pitch) arranged in a 3x3 grid directly under the package. Estimated junction rise based on PIC18F family datasheet typical values; actual dissipation depends on peripheral activation.
Place a 100 nF decoupling capacitor within 3 mm of each VDD pin pair (pin 11 VDD1/VDD2 and pin 32 VDD3) and a 10 uF bulk capacitor adjacent to the package. Use a star-ground topology routing analog AGND (pin 10) and digital GND (pins 12, 33) to a single-point ground via under the exposed pad. Keep ADC analog inputs (AN0-AN8, pins 2-9, 16, 17) physically separated from PWM outputs and the high-current switching nodes by at least 5 mm to prevent digital-to-analog crosstalk. The ICP clock/data signals (PGC/PGD, pins 39/40) require 4.7 kohm pull-ups to VDD for reliable ICD connection.
Three common pitfalls when designing with the PIC18F4431: (1) Forgetting configuration bit settings - the CONFIG1H register defaults to HS oscillator mode, which will fail to clock with the internal RC; always explicitly set CONFIG1H.OSC to match your oscillator hardware. (2) Using the FLTA pin (pin 23, RD4) without proper configuration - it defaults as a general-purpose I/O and will not assert PWM shutdown until configured in PWM1CON register. (3) Driving VDD above 5.5V will permanently damage the device - the absolute maximum VDD is 7.5V, but the operating range tops out at 5.5V per datasheet. Add a 5.6V TVS diode at the VDD pin for automotive load-dump protection.
合規資訊
RoHS compliant and lead-free matte-tin finish per Microchip product page. Extended -E temperature grade is not equivalent to AEC-Q100 automotive qualification; AEC-Q100 specific parts carry the -VAO suffix.
