PIC18LF4431T-I/ML - 8-bit 40MHz 16KB Flash MCU 44-QFN | Microchip
MPN: PIC18LF4431T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.74 | $2.74 |
| 10 | $2.46 | $24.60 |
| 100 | $2.19 | $219.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.74 | $1,740.00 |
PIC18LF4431T-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), data memory (RAM), and a rich set of peripherals such as ADCs, timers, communication interfaces, and GPIO. The PIC18LF4431 belongs to the 8-bit PIC RISC family, sitting within the broader hierarchy 8-bit MCU -> microcontroller -> embedded controller -> semiconductor. Its modified Harvard architecture and 16-bit instruction word provide higher code density than many 8-bit peers, while the LF process node enables lower active and sleep current draw for battery-powered designs.
Key features include an enhanced Flash program memory rated for typical 100K erase/write cycles, 10 MIPS sustained throughput at 40 MHz, multiple serial interfaces (I2C, SPI, UART/USART), a 10-bit ADC with up to 9 channels, and power-managed modes with fast wake-up. The 'T' suffix indicates Tape & Reel packaging and the 'I' suffix designates the industrial temperature grade of -40C to +85C, suitable for harsh environments.
Typical applications include motor control (the 4331/4431 sub-family is specifically designed for closed-loop brushless DC and switched-reluctance motor drives), sensor conditioning, industrial automation, white goods, and general-purpose embedded control where low-power, low-voltage operation and a compact QFN footprint are required.
When designing with this part, allocate sufficient PCB copper area beneath the exposed pad (EP) of the QFN-44 to meet thermal dissipation requirements and improve electrical grounding. Decouple VDD with at least 100 nF and 10 uF capacitors placed within 5 mm of the supply pins. The LF process limits maximum VDD to roughly 5.5 V, so verify rail tolerance if migrating from the F variant.
This page synthesizes distributor pricing, drop-in 44-QFN alternatives, parametric comparison, and practical QFN PCB layout guidance that go beyond the raw manufacturer datasheet, helping engineers accelerate motor-control and general-purpose 8-bit designs.
Drop-in alternatives for PIC18LF4431T-I/ML — 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 PIC18LF4431T-I/ML (same form factor and footprint) — differing in ADC, I/O Pins, Package, Mounting Type, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4331T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2431T-I/SO
✅ Drop-In✓ In Stock
$2.84 / Unit
View Datasheet →PIC18F4431T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4420T-I/ML
✅ Drop-In✓ In Stock
$3.79 / Unit
View Datasheet →PIC18LF4431T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Family | PIC18F2331/2431/4331/4431 |
| Sub-Family | PIC18LF4431 (low-voltage) |
| Maximum CPU Frequency | 40 MHz |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data RAM | 768 bytes |
| EEPROM | 256 bytes |
| ADC | 10-bit, 9 channels |
| I/O Pins | 34 |
| Operating Voltage | 2.0 V to 5.5 V |
| Communication Interfaces | I2C, SPI, UART/USART |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 44-QFN (8x8 mm) with EP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18LF4431T-I/ML Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 2 | OSC2/CLKOUT — Oscillator output |
| Pin 3 | MCLR — Master clear (reset) input |
| Pin 4 | RA0/AN0 — PORTA0 / Analog input 0 |
| Pin 5 | RA1/AN1 — PORTA1 / Analog input 1 |
| Pin 6 | RA2/AN2 — PORTA2 / Analog input 2 |
| Pin 7 | RA3/AN3 — PORTA3 / Analog input 3 |
| Pin 8 | RA4/AN4 — PORTA4 / Analog input 4 |
| Pin 9 | RA5/AN5 — PORTA5 / Analog input 5 |
| Pin 10 | RA6 — PORTA6 |
| Pin 11 | RA7 — PORTA7 |
| Pin 12 | VSS — Ground |
| Pin 13 | VDD — Positive supply |
| Pin 14 | RB0/INT0 — PORTB0 / External interrupt 0 |
| Pin 15 | RB1/INT1 — PORTB1 / External interrupt 1 |
| Pin 16 | RB2 — PORTB2 |
| Pin 17 | RB3 — PORTB3 |
| Pin 18 | RB4 — PORTB4 |
| Pin 19 | RB5 — PORTB5 |
| Pin 20 | RB6/PGC — PORTB6 / ICSP clock |
| Pin 21 | RB7/PGD — PORTB7 / ICSP data |
| Pin 22 | RC0 — PORTC0 |
| Pin 23 | RC1 — PORTC1 |
| Pin 24 | RC2 — PORTC2 |
| Pin 25 | RC3 — PORTC3 |
| Pin 26 | RC4 — PORTC4 |
| Pin 27 | RC5 — PORTC5 |
| Pin 28 | RC6 — PORTC6 |
| Pin 29 | RC7 — PORTC7 |
| Pin 30 | VSS — Ground |
| Pin 31 | VDD — Positive supply |
| Pin 32 | RD0 — PORTD0 |
| Pin 33 | RD1 — PORTD1 |
| Pin 34 | RD2 — PORTD2 |
| Pin 35 | RD3 — PORTD3 |
| Pin 36 | RD4 — PORTD4 |
| Pin 37 | RD5 — PORTD5 |
| Pin 38 | RD6 — PORTD6 |
| Pin 39 | RD7 — PORTD7 |
| Pin 40 | RE0 — PORTE0 |
| Pin 41 | RE1 — PORTE1 |
| Pin 42 | RE2 — PORTE2 |
| Pin 43 | RE3 — PORTE3 |
| Pin 44 | EP — Exposed pad (connect to VSS) |
Typical Applications
PIC18LF4431T-I/ML is suitable for 6 applications: Brushless DC Motor Control, Industrial Sensor Interface, Home Appliance Control, Automotive Auxiliary Pumps & Fans, Robotics & Small Drives, Switched-Mode Power Supply (SMPS) Digital Control.
Brushless DC Motor Control
The PIC18LF4431's integrated motor-control PWM (MCPWM) modules with complementary outputs, programmable dead-band, and 9-channel 10-bit ADC make it well suited to BLDC and PMSM motor drives. Its 40 MHz / 10 MIPS core handles field-oriented control (FOC) loops at sufficient update rates for small to mid-power industrial pumps, fans, and e-bike traction motors. The wide 2.0-5.5V supply range supports battery packs from 2S Li-ion up to 12V lead-acid.
Recommended
Industrial Sensor Interface
With 9 ADC channels, MSSP for I2C/SPI sensor communication, and 34 GPIO pins, the PIC18LF4431 can aggregate multiple analog and digital sensors in industrial monitoring systems. Its industrial -40C to +85C temperature range tolerates factory-floor conditions, while 256B EEPROM and 768B RAM support local data buffering, calibration tables, and averaging algorithms before reporting over UART or RS-485 to a central PLC.
Recommended
Home Appliance Control
The PIC18LF4431's combination of motor-control PWM, ADC, and UART makes it a candidate for washing machines, dishwashers, and HVAC damper actuators. Its LF voltage range supports direct 3.3V operation from switching pre-regulators, while the 16 KB Flash accommodates state-machine firmware plus UI handling for rotary encoders, LED indicators, and buzzer outputs. The exposed-pad QFN-44 ensures adequate thermal dissipation in sealed appliance enclosures.
Recommended
Automotive Auxiliary Pumps & Fans
While the standard PIC18LF4431 is not AEC-Q100, its industrial temperature grade (-40C to +85C) suits non-safety automotive loads such as coolant pumps, HVAC blowers, and seat ventilation fans in non-safety zones. The MSSP/I2C bus interfaces with body control modules (BCMs), and Enhanced USART supports LIN 1.2 slave mode for low-cost in-vehicle networking of auxiliary loads without requiring a CAN transceiver.
Recommended
Robotics & Small Drives
Small robotics platforms - from educational robots to hobby-class CNC spindles - benefit from the PIC18LF4431's quadrature encoder interface (QEI) for closed-loop position sensing and MCPWM for driving small brushless servo or stepper stages. The 10 MIPS performance handles trapezoidal commutation and basic PID loops, while the 16 KB Flash accommodates sensor-fusion and motion-planning routines in C for hobbyist-grade controllers.
Recommended
Switched-Mode Power Supply (SMPS) Digital Control
The PIC18LF4431's 10-bit ADC with fast sampling, MSSP for power-converter communication, and PWM peripherals enable digital control loops in low-to-mid-power SMPS designs. The 10 MIPS throughput supports average-current-mode control at switching frequencies up to 100 kHz, making the part applicable to telecom brick converters, LED drivers, and digitally controlled battery chargers. The 2.0-5.5V input range simplifies bootstrap startup from the same rail being regulated.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4431T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4331T-I/ML | PIC18F4431T-I/ML | PIC18LF2431T-I/SO |
|---|---|---|---|---|
| Package | 44-QFN (8x8 mm) | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 28-SOIC |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 8 KB | 16 KB | 16 KB |
| RAM | 768 bytes | 768 bytes | 768 bytes | 768 bytes |
| Operating Voltage | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 4.2 V to 5.5 V (F) | 2.0 V to 5.5 V (LF) |
| Max CPU Frequency | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| ADC Channels | 9 (10-bit) | 8 (10-bit) | 9 (10-bit) | 5 (10-bit) |
| Motor-Control PWM | Yes (MCPWM) | Yes | Yes | Yes |
Key Differentiators
- Highest-memory member of the 4331/4431 motor-control sub-family (vs PIC18LF4331T-I/ML)
- Lower operating voltage range supports battery-powered designs (vs PIC18F4431T-I/ML)
- 9-channel ADC for triple-shunt current sensing (vs PIC18LF2431T-I/SO)
Design Notes
The 44-QFN package dissipates heat through its exposed pad (EP) which is internally bonded to VSS. Solder the EP to a PCB copper pour of at least 25 mm^2 connected to the ground plane via 9 to 25 thermal vias (0.3 mm drill, 0.6 mm pad). Without this, theta_JA rises by 30-40 C/W, which is critical at 40 MHz full-load operation.
Place one 100 nF ceramic decoupling capacitor per VDD pin pair (pins 13 and 31), positioned within 3 mm of the IC. Add one bulk 10 uF tantalum or ceramic near each VDD pin for switching transients. For analog AVREF decoupling, use a separate 100 nF capacitor tied to AGND with a star-ground topology to avoid ADC noise coupling.
Route the ICSP lines PGC (RB6) and PGD (RB7) away from noisy motor PWM traces; a 4.7 kohm pull-up on MCLR is required for reliable in-circuit programming. The QFN-44 8x8 mm land pattern is non-standard (0.5 mm pitch); verify your PCB library uses the Microchip HVQCCN-44 footprint with correct thermal via pattern.
Do not exceed 5.5V on VDD for the LF variant - even transient spikes from motor switching can latch up the part. Add a TVS diode such as SMAJ5.0CA on VDD if the motor bus shares the supply. The 4331/4431 family's high-speed ADC requires the A/D acquisition time be set according to source impedance - 10 kOhm source impedance needs at least 2.4 us acquisition.
Compliance Information
RoHS and lead-free confirmed via Microchip product page. Not AEC-Q100 qualified - industrial grade only. For automotive safety applications, use AEC-Q100-qualified PIC18F variants or migrate to dsPIC33 EP series.
