PIC18F4431-E/PT - 8-Bit 40MHz 16KB Flash MCU | Microchip
MPN: PIC18F4431-E/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.65 | $9.65 |
| 10 | $8.93 | $89.30 |
| 100 | $7.85 | $785.00 |
| 500 | $6.95 | $3,475.00 |
| 1,000 | $6.1 | $6,100.00 |
PIC18F4431-E/PT Overview
What is a PIC18 microcontroller? PIC18F-series devices are 8-bit RISC microcontrollers built on Microchip's Harvard architecture with 77 instructions and 16-bit opcodes, providing higher performance and richer peripherals than the legacy PIC16 family. They sit in the broader taxonomy of microcontrollers (MCU) -> 8-bit MCU -> flash MCU -> enhanced flash MCU with nanoWatt technology, and are widely used in cost-sensitive embedded control where deterministic timing, low power, and motor-control PWM are required.
Key features of the PIC18F4431-E/PT include 36 digital I/O pins, an enhanced Power Control PWM module with up to six PWM outputs designed for variable-frequency, multi-pole motor drives, a programmable 16-bit timer/counter, two comparators, and a 10-bit ADC with up to 14 input channels. The device also features 4x phase-locked frequency synthesis for flexible oscillator configuration, a wide supply range of 4.2 V to 5.5 V, and nanoWatt power management modes such as sleep, idle, and low-power timer operation.
The PIC18F4431-E/PT is widely deployed in variable-frequency motor drives (BLDC, PMSM, ACIM), uninterruptible power supplies (UPS), industrial inverters, and digital power conversion. Its 14-bit dedicated PWM module with hardware fault input and dead-band control makes it particularly well-suited to driving 3-phase motor inverter bridges and high-frequency switching power supplies. The enhanced flash and nanoWatt features allow field-upgradeable firmware with low standby current.
Typical applications also include induction cooking controls, ceiling-fan and HVAC blower drives, servo amplifiers, and appliance motor control boards where the integrated motion-feedback module simplifies sensorless or closed-loop torque/speed control. The 44-pin TQFP package and 36 I/O pins leave headroom for user interfaces, encoder inputs, and communication ports.
When designing with the PIC18F4431-E/PT, ensure the input supply is well-decoupled with a 100 nF plus 10 uF combination and that the MCLR reset pin is pulled up through a resistor to VDD. The extended temperature grade ('-E' suffix) supports operation up to +125C, so verify thermal headroom in enclosed industrial enclosures.
This page synthesizes distributor pricing, drop-in alternatives from the same PIC18 family, and practical design notes not collected in a single place in the manufacturer datasheet.
Drop-in alternatives for PIC18F4431-E/PT — 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 PIC18F4431-E/PT (same form factor and footprint) — differing in Package, ADC, Communication, Operating Temperature, Program Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4431-I/PT
✅ Drop-In✓ In Stock
$4.79 / Unit
View Datasheet →PIC18F4331-I/PT
✅ Drop-In✓ In Stock
$3.05 / Unit
View Datasheet →PIC18F43K22-I/PT
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F4420-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F46K22-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4431-E/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard) |
| Maximum CPU Frequency | 40 MHz (10 MIPS) |
| Program Memory | 16 KB Flash (8K x 16) |
| Data RAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, up to 14 channels |
| PWM Modules | Power Control PWM, 14-bit, up to 6 outputs |
| Timers | 1x 16-bit, 3x 8-bit |
| Communication | USART, MSSP (SPI / I2C) |
| Comparators | 2 |
| Package | 44-pin TQFP (10x10 mm) |
| Operating Temperature | -40C to +125C (extended, -E suffix) |
| RoHS Status | Compliant |
| Mounting Type | Surface Mount |
PIC18F4431-E/PT Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, internal pull-up |
| Pin 2 | RA0/AN0 — Digital I/O / Analog input 0 |
| Pin 3 | RA1/AN1 — Digital I/O / Analog input 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / Analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4 — Digital I/O / Analog input 4 |
| Pin 8 | RE0/RD — Digital I/O / Parallel port read |
| Pin 9 | RE1/WR — Digital I/O / Parallel port write |
| Pin 10 | RE2/CS — Digital I/O / Parallel port chip select |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Crystal oscillator input / external clock |
| Pin 14 | OSC2/CLKOUT — Crystal oscillator output / clock out |
| Pin 15 | RC0/T1OSO — Digital I/O / Timer1 oscillator output |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — Digital I/O / CCP1 |
| Pin 18 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O / Parallel slave port bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O / Parallel slave port bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O / Parallel slave port bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O / Parallel slave port bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O / SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O / USART TX / clock |
| Pin 26 | RC7/RX/DT — Digital I/O / USART RX / data |
| Pin 27 | RD4/PSP4 — Digital I/O / Parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O / Parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O / Parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O / Parallel slave port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT0/FLT0 — Digital I/O / External interrupt 0 / PWM fault 0 |
| Pin 34 | RB1/INT1 — Digital I/O / External interrupt 1 |
| Pin 35 | RB2/INT2 — Digital I/O / External interrupt 2 |
| Pin 36 | RB3/INT3/CCP2 — Digital I/O / External interrupt 3 / CCP2 |
| Pin 37 | RB4 — Digital I/O |
| Pin 38 | RB5 — Digital I/O |
| Pin 39 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 40 | RB7/PGD — Digital I/O / ICSP data |
| Pin 41 | PWM1 — Power Control PWM output 1 |
| Pin 42 | PWM2 — Power Control PWM output 2 |
| Pin 43 | PWM3 — Power Control PWM output 3 |
| Pin 44 | PWM4 — Power Control PWM output 4 |
Typical Applications
PIC18F4431-E/PT is suitable for 6 applications: BLDC / PMSM Motor Drive, Uninterruptible Power Supply (UPS), Induction Cooking / Resonant Power, Industrial Variable-Frequency Drive (VFD), Solar Micro-Inverter / Power Optimizer, HVAC Blower and Compressor Control.
BLDC / PMSM Motor Drive
The PIC18F4431-E/PT's dedicated 14-bit Power Control PWM module with 6 outputs, programmable dead-band, and hardware fault input makes it ideal for 3-phase brushless DC and permanent-magnet synchronous motor drives. Its 40 MHz core delivers 10 MIPS of processing bandwidth, sufficient for inner-loop current control at 10-20 kHz PWM. The integrated motion-feedback module simplifies sensorless BEMF zero-crossing or Hall-sensor-based commutation. For ceiling fans, pump drives, and appliance motors, this MCU removes the need for an external gate driver DSP.
Recommended
Uninterruptible Power Supply (UPS)
The PIC18F4431-E/PT runs the digital control loop in line-interactive and online UPS systems, where it generates sinusoidal PWM for the inverter bridge and performs battery charging profile management. The 14-bit Power Control PWM gives fine voltage resolution at the inverter output, while the 10-bit ADC samples battery voltage and current with adequate resolution for state-of-charge estimation. Its 4.2-5.5V supply aligns with auxiliary 5V rails, simplifying the housekeeping supply chain. The extended -40C to +125C temperature range supports harsh industrial UPS enclosures.
Recommended
Induction Cooking / Resonant Power
In induction cooktops and resonant heating converters, the PIC18F4431-E/PT drives high-frequency IGBTs at 20-100 kHz with precise dead-time control using its Power Control PWM. The 14-bit PWM resolution gives 12-15 mV step at a 200 V bus - critical for accurate power level setting. Its hardware fault input provides sub-microsecond overcurrent shutdown, protecting the resonant tank from runaway. The MCU also runs the user-interface scan and temperature regulation loop concurrently with the resonant control.
Recommended
Industrial Variable-Frequency Drive (VFD)
Three-phase industrial VFDs for fans, pumps, and conveyors use the PIC18F4431-E/PT as the main control MCU because its 6-PWM output directly drives the inverter stage with dead-band and polarity control. The 14-bit motion-feedback module performs field-oriented control for AC induction motors, calculating slip frequency and torque-producing current. The 36 digital I/O lines accommodate encoder inputs, keypad scanning, status LEDs, and Modbus UART - eliminating the need for an external I/O expander. Extended temperature grade (-40C to +125C) handles factory-floor ambient.
Recommended
Solar Micro-Inverter / Power Optimizer
In solar micro-inverters and panel-mounted DC-DC optimizers, the PIC18F4431-E/PT implements MPPT algorithms and generates the grid-tie sinusoidal PWM. Its 14-bit Power Control PWM and 10-bit ADC sample PV string voltage and current fast enough for perturb-and-observe MPPT at sub-second intervals. The wide 4.2-5.5V supply accepts auxiliary rails derived from the PV module itself. The extended temperature grade supports rooftop operation where ambient can exceed 70C in direct sun.
Recommended
HVAC Blower and Compressor Control
ECM (electronically commutated) motors in HVAC blowers, fans, and compressors leverage the PIC18F4431-E/PT's dedicated motor-control PWM to deliver variable-speed efficiency gains over fixed-speed PSC motors. The motion-feedback module simplifies sensorless rotor-position detection, reducing BOM cost by eliminating Hall-effect sensors. The 36 I/O pins accept thermostat inputs, tacho feedback, and triac-compatible outputs for legacy installations. The -40C to +125C grade handles attic and outdoor unit thermal stress.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4431-E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4431-I/PT | PIC18F4331-I/PT | PIC18F43K22-I/PT | PIC18F4420-I/PT | PIC18F46K22-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (10x10 mm) | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same | TQFP-44 - same |
| Flash Memory | 16 KB | 16 KB | 8 KB | 8 KB | 16 KB | 64 KB |
| RAM | 768 B | 768 B | 336 B | 512 B | 768 B | 3896 B |
| Power Control PWM | Yes (14-bit, 6 outputs) | Yes (14-bit, 6 outputs) | Yes (14-bit, 6 outputs) | No (only CCP/ECCP) | No (only CCP/ECCP) | No (only CCP/ECCP) |
| ADC | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 14 channels | 12-bit, 19 channels | 10-bit, 13 channels | 12-bit, 28 channels |
| Operating Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 1.8 V to 5.5 V (XLP) | 2.0 V to 5.5 V | 1.8 V to 5.5 V (XLP) |
| Operating Temperature | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) |
Key Differentiators
- Dedicated 14-bit Power Control PWM with hardware fault input (vs PIC18F43K22-I/PT)
- Doubled flash and RAM vs PIC18F4331 (vs PIC18F4331-I/PT)
- Extended -40C to +125C industrial temperature grade (vs PIC18F4431-I/PT)
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of pins 11 and 32, plus a bulk 10 uF tantalum or ceramic near the package. The PIC18F4431-E/PT has two VDD pins (11, 32) and two VSS pins (12, 31) - both must be connected, with the trace from each VDD pin having its own decoupling. Brown-out reset is set by the BOREN fuse and is recommended for motor-control applications where VDD may dip under heavy inrush.
Estimated: at 40 MHz with all peripherals active, the core draws roughly 25 mA from VDD (~125 mW). In the 44-pin TQFP (10x10 mm) with theta_JA approximately 60 C/W on a 2-layer JEDEC test board, this yields a 7.5C junction rise - well within limits. For sealed industrial enclosures exceeding 70C ambient, derate by adding copper area under the exposed pad footprint or down-clock to 20 MHz for thermal margin.
Keep the 40 MHz crystal traces short and symmetric, with the load capacitors (typically 15-33 pF) placed directly on OSC1/OSC2. Route the Power Control PWM outputs (pins 41-44) as far as possible from the analog ADC inputs to minimize digital switching noise coupling. For 3-phase motor drive boards, use a 4-layer stack-up with a solid ground plane beneath the MCU to provide both thermal spreading and EMI shielding for the analog reference.
Do not leave MCLR floating - it requires a 10 kohm pull-up to VDD for normal operation and ICSP programming. The PWM fault input (FLT0/RB0) defaults to a disabled state; if unused, configure it as an analog input or digital input with the internal pull-up enabled. The ICSP pins RB6/RB7 must be accessible for in-circuit programming - do not populate them with low-impedance loads that would prevent programming mode entry.
Compliance Information
RoHS and lead-free per Microchip product page; not AEC-Q100 qualified (industrial-grade MCU); halogen-free status not specified.