PIC18LF2431-I/SP - 8-Bit 40MHz 16KB Flash MCU | Microchip
MPN: PIC18LF2431-I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.45 | $64.50 |
| 100 | $5.55 | $555.00 |
| 500 | $4.95 | $2,475.00 |
| 1,000 | $4.4 | $4,400.00 |
PIC18LF2431-I/SP Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O on one die. Within the broader power-management and embedded-control taxonomy, the PIC18LF2431 sits in the 8-bit RISC MCU class (8-bit MCU -> microcontroller -> embedded processor -> semiconductor). The LF variant specifically targets low-voltage (2.0 V to 5.5 V) operation, making it compatible with both 3.3 V and 5 V rails found in industrial and consumer designs.
Key features include 22 I/O pins, two 8-bit timers and three 16-bit timers, a 10-bit A/D converter with up to 5 analog inputs, two capture/compare/PWM modules, two comparators, a USART, and an MSSP (SPI/I2C). The nanoWatt power-managed modes provide idle, sleep, and ultra-low-power operation, suiting battery-powered and energy-conscious applications. The high-performance PWM module supports center-aligned and complementary outputs for driving three-phase motor stages.
Architecturally, the device is built on an enhanced Harvard RISC core with a 16-bit instruction word and 8-bit data path, allowing single-cycle execution for most instructions at 40 MHz (10 MIPS). The integrated 10-bit ADC and configurable PWM make it a strong fit for closed-loop motor control, switch-mode power supply (SMPS) feedback, and other real-time embedded applications.
Typical applications include brushless DC (BLDC) and permanent-magnet synchronous motor (PMSM) control, uninterruptible power supplies, induction cooking, fan and pump controllers, and LED lighting power-conversion stages. Its 28-pin SPDIP footprint suits through-hole prototyping and industrial modules where robust mechanical connections are required.
When designing with this device, ensure decoupling capacitors are placed close to VDD/VSS pairs and that the MCLR reset line is pulled high through a 10 kohm resistor for reliable startup. For noise-sensitive analog readings, dedicate an AVSS/AVDD pair and avoid routing PWM signals adjacent to the ADC inputs.
This page synthesizes distributor pricing, drop-in alternatives drawn from Microchip's PIC18 family, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18LF2431-I/SP — 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 PIC18LF2431-I/SP (same form factor and footprint) — differing in Package, ADC, Communication, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2431-I/SP
✅ Drop-In✓ In Stock
$5.49 / Unit
View Datasheet →PIC18LF2331-I/SP
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC18LF242-I/SP
✅ Drop-In✓ In Stock
$2.75 / Unit
View Datasheet →PIC18LF2221-I/SP
✅ Drop-In✓ In Stock
$2.78 / Unit
View Datasheet →PIC18LF2431-I/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC enhanced Harvard |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data RAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum Clock Speed | 40 MHz |
| MIPS | 10 MIPS |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| I/O Pins | 22 |
| A/D Converter | 10-bit, up to 5 channels |
| PWM Channels | High-performance PWM, 3 pairs complementary |
| Timers | 2 x 8-bit, 3 x 16-bit |
| Communication | 1 x USART, 1 x MSSP (SPI/I2C) |
| Comparators | 2 |
| Capture/Compare/PWM | 2 CCP modules |
| Package | 28-pin SPDIP (0.300 inch) |
| Mounting Type | Through-Hole |
| Operating Temperature | -40C to +85C (Industrial) |
| Power-Saving Modes | nanoWatt (Idle, Sleep, etc.) |
PIC18LF2431-I/SP Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active low |
| 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 / A/D reference low |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / A/D reference high |
| Pin 6 | RA4/AN4 — PORTA bit 4 / analog input 4 |
| Pin 7 | RA5 — PORTA bit 5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI — Crystal oscillator input / external clock |
| Pin 10 | OSC2/CLKO — Crystal oscillator output |
| Pin 11 | RC0/T1OSO — PORTC bit 0 / Timer1 oscillator output |
| Pin 12 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 13 | RC2/PWM1 — PORTC bit 2 / PWM output 1 |
| Pin 14 | RC3/PWM2 — PORTC bit 3 / PWM output 2 |
| Pin 15 | RC4/PWM3 — PORTC bit 4 / PWM output 3 |
| Pin 16 | RC5 — PORTC bit 5 |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 22 | RB1 — PORTB bit 1 |
| Pin 23 | RB2 — PORTB bit 2 |
| Pin 24 | RB3 — PORTB bit 3 |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18LF2431-I/SP is suitable for 6 applications: Brushless DC (BLDC) Motor Control, Switch-Mode Power Supply (SMPS) Control, Uninterruptible Power Supply (UPS) Control, Induction Cooking Appliance Control, LED Lighting Power Converters, Industrial Fan and Pump Speed Control.
Brushless DC (BLDC) Motor Control
The PIC18LF2431-I/SP is purpose-built for three-phase BLDC motor control per Microchip datasheet 39616D. Its high-performance PWM module generates center-aligned complementary outputs for driving a 3-phase inverter with dead-band control. The 10-bit ADC samples back-EMF or shunt current at up to 100 ksps, while two on-chip comparators provide hardware overcurrent protection. With 16 KB Flash and 768 bytes RAM, the device supports sensorless or sensored BLDC commutation firmware including field-oriented control (FOC) entry-level algorithms. Operating from 2.0-5.5 V, the LF variant suits battery-powered tools, fans, pumps, and small EV traction systems where compact through-hole mounting is preferred.
Recommended
Switch-Mode Power Supply (SMPS) Control
The PIC18LF2431-I/SP is widely used as an SMPS primary-side controller per Microchip datasheet 39616D. Its high-speed 10-bit ADC monitors output voltage and primary current at fixed switching rates up to 100 kHz. The high-performance PWM produces variable-duty or constant-frequency drive signals for MOSFET/IGBT switches, with built-in current-mode control support. Operating at 40 MHz (10 MIPS), the firmware can implement peak-current-mode, average-current-mode, or hysteretic control loops in real time. The nanoWatt low-power modes reduce standby consumption below 1 uA, helping designs meet Energy Star and DoE Level VI efficiency requirements for adapters and LED drivers.
Recommended
Uninterruptible Power Supply (UPS) Control
The PIC18LF2431-I/SP is suitable for small UPS and inverter control applications per Microchip datasheet 39616D. Its 22 I/O pins handle multiple status LEDs, relay drivers, and battery-monitoring inputs simultaneously. The 10-bit ADC reads battery voltage, charge current, and temperature at high sampling rates to manage charge profiles and detect end-of-discharge. Three 16-bit timers provide accurate line-frequency measurement (50/60 Hz) for synchronization, while the USART enables communication with a host BMS. The 28-pin SPDIP package is easy to prototype, making the part popular for educational and small commercial UPS designs.
Recommended
Induction Cooking Appliance Control
The PIC18LF2431-I/SP is designed for induction cooker control loops thanks to its high-performance PWM and fast ADC per Microchip datasheet 39616D. The PWM module drives an IGBT or MOSFET half-bridge at 20-100 kHz with adjustable dead time to protect resonant tank components. The integrated analog front end (op amps and comparators) detects pan presence, resonant zero-crossing, and overcurrent faults in real time. Software implemented in 16 KB Flash handles pan-detection algorithms, soft-start, and power-level modulation per user input. The wide 2.0-5.5 V supply range simplifies auxiliary supply design from rectified mains.
Recommended
LED Lighting Power Converters
The PIC18LF2431-I/SP is used in digitally controlled LED drivers for commercial and industrial luminaires per Microchip datasheet 39616D. Its high-performance PWM supports analog dimming by directly modulating the converter duty cycle, while the 10-bit ADC reads photodiode or output current feedback for closed-loop constant-current regulation. The USART or MSSP interfaces with DMX512, DALI, or 0-10 V dimming modules. Operating from 2.0-5.5 V and offering nanoWatt sleep modes, the device supports Energy Star standby requirements under 0.5 W. The 28-pin SPDIP is convenient for through-hole driver-board prototypes.
Recommended
Industrial Fan and Pump Speed Control
The PIC18LF2431-I/SP is well suited to variable-frequency drives for industrial fans, blowers, and small pumps per Microchip datasheet 39616D. The 10-bit ADC samples motor back-EMF or DC link voltage for sensorless speed estimation, while the high-performance PWM produces the sine-modulated or trapezoidal drive signals. The 16 KB Flash holds VF (volts-per-hertz) or simple FOC algorithms along with communication stacks (Modbus RTU over USART). Robust operation from -40 C to +85 C industrial temperature range and through-hole SPDIP packaging suit factory-floor installations and HVAC equipment.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF2431-I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2431-I/SP | PIC18LF2331-I/SP | PIC18LF242-I/SP | PIC18LF2221-I/SP |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-pin SPDIP | 28-pin SPDIP | 28-pin SPDIP | 28-pin SPDIP | 28-pin SPDIP |
| Program Memory (Flash) | 16 KB | 16 KB | 8 KB | 16 KB | 4 KB |
| RAM | 768 B | 768 B | 256 B | 768 B | 384 B |
| Maximum Clock Speed | 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 | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| A/D Converter | 10-bit, 5 channels | 10-bit, 5 channels | 10-bit, 5 channels | 10-bit, 5 channels | 10-bit, 5 channels |
| PWM Channels | 3 pairs complementary | 3 pairs complementary | 3 pairs complementary | 2 pairs | 1 pair |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Low-voltage LF operation (vs PIC18F2431-I/SP)
- Doubled program memory versus PIC18LF2331 (vs PIC18LF2331-I/SP)
- Three complementary PWM pairs (vs PIC18LF2221-I/SP)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to each VDD/VSS pair (pins 20 and 8/19) on the PIC18LF2431-I/SP. For the analog AVdd/AVss pair, use a separate 100 nF plus a 10 uF bulk capacitor to suppress ADC reference noise. The on-chip LDO and bandgap reference are sensitive to high-frequency ripple; avoid routing high-current switching traces adjacent to the analog supply pins.
Keep PWM output traces short and away from sensitive analog inputs to avoid capacitive coupling into ADC readings. Use a star-ground connection at the PIC18LF2431-I/SP GND pin for power-stage return currents. When routing complementary PWM outputs (PWM1/PWM2/PWM3), match lengths within 5 mm to avoid timing skew in motor-drive applications.
The MCLR reset pin on the PIC18LF2431-I/SP must be pulled high through a 10 kohm resistor to VDD for reliable operation; floating MCLR causes spurious resets. Configure unused I/O pins as outputs driven low (not inputs) to minimize current consumption in nanoWatt sleep mode. For ICSP programming, pins 27 (PGC) and 28 (PGD) must be accessible and not driven by external circuitry during programming.
Compliance Information
RoHS compliant per Microchip product page; LF suffix indicates low-voltage variant. Not AEC-Q100 qualified - choose PIC18F2431 automotive grades for automotive use.
