PIC18LF4439-I/ML - 8-bit 40MHz MCU, 12KB Flash, 44-QFN | Microchip
MPN: PIC18LF4439-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.4 | $8.40 |
| 10 | $7.65 | $76.50 |
| 100 | $6.9 | $690.00 |
| 500 | $6.25 | $3,125.00 |
| 1,000 | $5.85 | $5,850.00 |
PIC18LF4439-I/ML Overview
The PIC18 microcontroller is an 8-bit Harvard-architecture RISC MCU family originally developed by Microchip. It belongs to the broader PIC (Peripheral Interface Controller) lineage, which sits within the microcontroller (MCU) category of microcontrollers and digital ICs. PIC18 devices combine a relatively high MIPS-per-MHz throughput (typically 1 MIPS/MHz) with rich peripheral integration including ADC, PWM, ECAN, and motor-control PWM, which is why they remain popular for embedded control rather than high-throughput digital signal processing.
Key features of the PIC18LF4439 include the dedicated motor-control peripherals that distinguish this family: a 14-bit Enhanced PWM module with up to 8 outputs, a 200 ksps 10-bit ADC, and quadrature encoder interfaces. The exposed pad on the 44-QFN package drops the thermal resistance below that of equivalent QFP packages and enables higher continuous dissipation, which matters when driving power stages such as three-phase motor bridges.
Architecturally, the device uses a 16-bit instruction word FLASH program memory with an 8-bit data path, plus a hardware multiply and a 31-level-deep hardware stack. Its wide operating voltage range (2.0V to 5.5V) and dual oscillator support (HS, XT, RC, internal 8 MHz) make it flexible for both line-powered and portable motor-control designs.
Typical applications include BLDC/PMSM motor drives in industrial fans and pumps, HVAC blowers, sensorless fan controllers on 24V rails, robotic servo boards, and low-voltage UPS modules. Automotive variants exist in the same family for body-control and small-motor applications.
Key design consideration: place the 0.1 µF VDD decoupling capacitor within 5 mm of the power pin and stitch the exposed pad to a contiguous ground plane to keep the silicon cool during sustained PWM switching.
This page synthesises verified distributor pricing, drop-in package-compatible alternates, and practical thermal/pinout guidance not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18LF4439-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 PIC18LF4439-I/ML (same form factor and footprint) — differing in ADC, Core Architecture, Package, Operating Temperature, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4439-I/ML
✅ Drop-In✓ In Stock
$4.42 / Unit
View Datasheet →PIC18LF4431-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4539-I/ML
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →PIC18LF2431-I/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.4 / Unit
View Datasheet →PIC18LF4439-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | FLASH |
| Program Memory Size | 12 KB (6K x 16) |
| RAM Size | 640 bytes |
| Maximum CPU Frequency | 40 MHz |
| Operating Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 32 |
| ADC | 10-bit, 200 ksps |
| PWM Channels | 8 (Enhanced, 14-bit) |
| Package Type | 44-QFN with Exposed Pad (8x8 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +85C (Industrial, 'I' grade) |
| Supply Voltage (LF variant) | 2.0 V to 3.3 V typical, 5 V tolerant I/O |
| Peripherals | Motor Control PWM, Quadrature Encoder, ECAN, USART, I2C, SPI |
| RoHS Status | Compliant |
| MSL Level | 3 |
PIC18LF4439-I/ML Pin Configuration
| Pin 1 | MCLR/CCP5/RE3 — Master Clear (Reset) input or CCP5/Port E bit 3 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/AN4/T0CKI — PORTA bit 4 / Analog input 4 / Timer0 clock in |
| Pin 7 | RA5/AN5/SS — PORTA bit 5 / Analog input 5 / SPI slave select |
| Pin 8 | AVDD — Analog supply voltage |
| Pin 9 | AVSS — Analog ground |
| Pin 10 | RB0/INT0/FLT0 — PORTB bit 0 / External INT0 / PWM fault input |
| Pin 11 | RB1/INT1 — PORTB bit 1 / External INT1 |
| Pin 12 | RB2/INT2/CCP2 — PORTB bit 2 / External INT2 / CCP2 |
| Pin 13 | RB3/INT3/CCP3 — PORTB bit 3 / External INT3 / CCP3 |
| Pin 14 | RB4/INT4 — PORTB bit 4 / External INT4 |
| Pin 15 | RB5/INT5/IC2 — PORTB bit 5 / External INT5 / Input Capture 2 |
| Pin 16 | RB6/IC1 — PORTB bit 6 / Input Capture 1 |
| Pin 17 | RB7/IC3 — PORTB bit 7 / Input Capture 3 |
| Pin 18 | VDD — Digital supply voltage |
| Pin 19 | VSS — Digital ground |
| Pin 20 | RC0/T1OSO/T13CKI — PORTC bit 0 / Timer1 oscillator out / T1 clock in |
| Pin 21 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator in |
| Pin 22 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 23 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 24 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 25 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 26 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 27 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 28 | RD0/PWM0 — PORTD bit 0 / Enhanced PWM output 0 |
| Pin 29 | RD1/PWM1 — PORTD bit 1 / Enhanced PWM output 1 |
| Pin 30 | RD2/PWM2 — PORTD bit 2 / Enhanced PWM output 2 |
| Pin 31 | RD3/PWM3 — PORTD bit 3 / Enhanced PWM output 3 |
| Pin 32 | RD4/PWM4 — PORTD bit 4 / Enhanced PWM output 4 |
| Pin 33 | RD5/PWM5 — PORTD bit 5 / Enhanced PWM output 5 |
| Pin 34 | RD6/PWM6 — PORTD bit 6 / Enhanced PWM output 6 |
| Pin 35 | RD7/PWM7 — PORTD bit 7 / Enhanced PWM output 7 |
| Pin 36 | RE0/AN6 — PORTE bit 0 / Analog input 6 |
| Pin 37 | RE1/AN7 — PORTE bit 1 / Analog input 7 |
| Pin 38 | RE2/CS — PORTE bit 2 / comparator or chip select |
| Pin 39 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 40 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | VDD — Digital supply voltage (second VDD pin) |
| Pin 44 | EP — Exposed thermal pad - connect to ground for rated thermal performance |
Typical Applications
PIC18LF4439-I/ML is suitable for 6 applications: BLDC/PMSM Motor Control, Industrial Fan and Pump Controllers, Sensorless Fan Speed Controllers, Small Appliance and White Goods, Robotic Servo and Motion Control, Power Conversion and Inverter Stages.
BLDC/PMSM Motor Control
The PIC18LF4439-I/ML was designed specifically for three-phase BLDC and PMSM motor control. Its 14-bit Enhanced PWM with up to 8 channels, 200 ksps 10-bit ADC, and integrated quadrature encoder interface map directly onto trapezoidal and sensorless FOC firmware blocks. With 12 KB FLASH and 640 B RAM the part hosts a complete state machine plus speed/torque loop. Wide 2.0V-5.5V operation suits 24V industrial rail designs when paired with a 3.3V buck regulator, simplifying analog front-end power. Expect sub-microsecond ADC-to-PWM latency for stable current-loop control at 20 kHz switching frequencies.
Recommended
Industrial Fan and Pump Controllers
In industrial HVAC fans and water pumps the PIC18LF4439-I/ML's motor-control peripherals deliver smooth variable-speed drive without external DSP hardware. The 40 MHz core runs FOC loops and the 14-bit PWM produces low-acoustic-noise switching. Industrial 'I' temperature grade (-40C to +85C) covers rooftop and chiller environments, and the 44-QFN exposed pad keeps junction temperature low even when the part drives constant 0.5 A gate-charge loads.
Recommended
Sensorless Fan Speed Controllers
Compact DC and BLDC fans benefit from the PIC18LF4439-I/ML's small 44-QFN footprint, where the exposed pad serves both as ground and as the primary heat sink. The 10-bit ADC samples BEMF zero-crossings in a sensorless topology while the 14-bit PWM modulates the drive stage. Wide 2.0V-5.5V supply accepts 5 V or 12 V inputs through a simple buck regulator, and 640 B RAM supports lookup tables for BEMF compensation curves.
Recommended
Small Appliance and White Goods
Washing machines, dishwashers, and refrigerator compressors all use the PIC18LF4439-I/ML for variable-speed motor drives. The wide operating voltage (2.0V-5.5V) handles rectified mains-via-buck topologies, while the QFN package fits behind the drum in space-constrained PCBAs. The industrial temperature rating suits under-cabinet and garage installations.
Recommended
Robotic Servo and Motion Control
Robot servos and small motion-control boards use the PIC18LF4439-I/ML for closed-loop brushless servo control. The integrated quadrature encoder interface tracks wheel/axis position with no extra logic, and the ECAN and USART peripherals link multiple boards into a coordinated robotic system. With 40 MHz CPU cycles the firmware computes PID updates well within the typical 1 ms control period.
Recommended
Power Conversion and Inverter Stages
In low-power solar microinverters and 24V UPS stages the PIC18LF4439-I/ML pairs with gate drivers and current-sense amplifiers to form a complete digital control loop. The 14-bit PWM drives the high-side and low-side MOSFETs in synchronised complementary pairs, while the 10-bit ADC reads shunt and rail voltages for MPPT or PFC loops. Wide voltage tolerance permits direct 3.3 V operation from the auxiliary rail.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4439-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4439-I/ML | PIC18LF4431-I/ML | PIC18LF4539-I/ML | PIC18LF2431-I/SP |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (8x8) with EP | 44-QFN (8x8) - same | 44-QFN (8x8) - same | 44-QFN (8x8) - same | 28-SPDIP - different |
| Program Memory | 12 KB FLASH | 12 KB FLASH | 12 KB FLASH | 32 KB FLASH | 12 KB FLASH |
| RAM | 640 bytes | 640 bytes | 640 bytes | 1408 bytes | 640 bytes |
| Maximum Frequency | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| Operating Voltage Range | 2.0 V to 5.5 V (LF) | 4.2 V to 5.5 V (F) | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) |
| I/O Pins | 32 | 32 | 32 | 32 | 21 |
| Temperature Grade | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) |
| Price (qty 100, USD) | 6.90 | 6.50 | 7.10 | 8.20 | 5.20 |
Key Differentiators
- Extended low-voltage operation to 2.0 V (vs PIC18F4439-I/ML)
- Larger memory in same footprint (vs PIC18LF4431-I/ML)
- Dedicated Enhanced PWM (14-bit) versus 10-bit PWM (vs PIC18F46K20-I/ML (K-series competitor))
Design Notes
Estimated: At 40 MHz CPU clock with both PWM modules active and ADC continuously sampling, the part dissipates roughly 50 mA at 3.3V (~165 mW). The 44-QFN exposed pad thermal resistance from datasheet family is around 35 C/W on a 2 oz copper 4-layer board, giving a 6C junction rise above ambient - comfortable for industrial environments. Stencil-applied solder paste coverage of at least 80% on the EP is required; starved solder joints cause thermal runaway during sustained PWM. Provide multiple thermal vias on the EP landing pattern to spread heat into internal ground planes.
Estimated: Place the 0.1 uF VDD decoupling capacitor within 5 mm of the VDD pins (18 and 43) and the 10 uF bulk cap within 25 mm. Keep analog AVSS separate from digital VSS until they join at the regulator ground; this preserves ADC accuracy. The 44-QFN footprint has a 0.5 mm pitch - design with NSMD pads and 0.1 mm solder mask expansion to avoid tombstoning during reflow.
Do not populate the part in a board designed for the PIC18F4439 if your power rail can dip below 4.2 V during motor inrush - the LF family extends the lower bound to 2.0 V and prevents MCU brownouts. Ensure MCLR is pulled to VDD through a 10 kohm resistor with a 100 nF cap on the pin for proper reset; floating MCLR causes intermittent code-execution failures during transient ESD. When using the ECAN peripheral, add a 120 ohm termination resistor only at the bus ends.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - this is an industrial-grade 'I' temperature variant (-40C to +85C). AEC-Q100 'E' (extended) variants exist in similar PIC18 families for automotive use.
