PIC18LF2431T-I/SO - 8-bit 40MHz MCU 16KB Flash 28-SOIC | Microchip
MPN: PIC18LF2431T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.32 | $4.32 |
| 10 | $3.89 | $38.90 |
| 100 | $3.51 | $351.00 |
| 500 | $3.18 | $1,590.00 |
| 1,000 | $2.84 | $2,840.00 |
PIC18LF2431T-I/SO Overview
An 8-bit PIC microcontroller is a single-chip computer integrating a CPU core, Flash program memory, RAM, EEPROM, peripherals and I/O on one die. The PIC18 family extends Microchip's baseline 8-bit portfolio with a 16-bit instruction word, hardware multiply, C-friendly architecture and a 10 MIPS CPU, positioning it between entry-level PIC16 devices and the 16-bit dsPIC/PIC24 line. The PIC18LF2431 in particular is designed for cost-sensitive motor-control and power-conversion applications because it integrates a dedicated 14-bit Power Control PWM module with dedicated time-base and duty-cycle registers, plus a 10-bit ADC and analog comparators.
Key features of the PIC18LF2431T-I/SO include 16 KB (8K x 16) of self-programmable Flash, 768 bytes of SRAM, 256 bytes of EEPROM, a 10-bit ADC with up to 9 channels, two analog comparators, two CCP modules, the motor-control Power Control PWM with up to 6 channels, a master synchronous serial port (MSSP) configurable as SPI or I2C, an Enhanced USART, two 8-bit timers plus three 16-bit timers, a 22-strong digital I/O set, and an internal 31 kHz to 8 MHz oscillator block with PLL support. The integrated 5V tolerant I/O and rich analog front-end reduce external component count in BLDC, brushed DC and PFC designs.
Typical applications span consumer and industrial three-phase and single-phase motor control, switched-mode power supplies with power-factor correction, UPS systems, induction heating and digital lighting ballasts. The 28-SOIC package is suitable for hand-soldered prototypes, through-hole adapter boards and cost-optimised production where the 40-pin variants (PIC18F2431-I/P, PIC18F4431-I/P) are not required.
When designing with this part, take care that any code developed for the F variant (4.2V-5.5V) is checked for the lower LF voltage window. In-circuit serial programming (ICSP) and the standard 5-wire ICD header can be used without any external reset supervisor thanks to the integrated brown-out and power-on reset blocks. For new designs Microchip recommends migrating to the PIC18F/K-series K22 family where pin-compatible equivalents are available.
Drop-in alternatives for PIC18LF2431T-I/SO — 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 PIC18LF2431T-I/SO (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, ADC, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF2431-I/SO
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →PIC18LF2431-I/SP
✅ Drop-In✓ In Stock
$4.4 / Unit
View Datasheet →PIC18F2431-I/SO
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC18LF2331-I/SO
✅ Drop-In✓ In Stock
$4.88 / Unit
View Datasheet →PIC18LF4331-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2431T-I/SO Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC18 (RISC, 16-bit instruction word) |
| Family | PIC18F/LF 2431/2331/4431/4331 |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data SRAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Supply Voltage (VDD) | 2.0 V to 5.5 V (LF family) |
| I/O Pins | 22 |
| Package | 28-SOIC (7.50 mm body width) |
| Mounting Type | Surface Mount (Gull-Wing) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| ADC | 10-bit, up to 9 channels |
| Analog Comparators | 2 |
| PWM Module | Power Control PWM (14-bit), up to 6 channels |
| CCP Modules | 2 |
| Timers | 2 x 8-bit + 3 x 16-bit |
| Communication | 1 x MSSP (SPI/I2C) + 1 x Enhanced USART |
| Internal Oscillator | 31 kHz to 8 MHz with PLL (4x, 8 MHz to 32 MHz) |
| MSL Level | MSL1 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC18LF2431T-I/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Digital I/O / analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input channel 1 |
| Pin 4 | RA2/AN2/VREF-/CVREF — Digital I/O / analog input channel 2 / negative VREF / comparator VREF output |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / analog input channel 3 / positive VREF |
| Pin 6 | RA4/T0CKI/RCV — Digital I/O / Timer0 clock input / PWM Fault input |
| Pin 7 | RA5/AN4/SS/HLVDIN — Digital I/O / analog input channel 4 / SPI Slave Select / high/low-voltage detect input |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock input / digital I/O |
| Pin 10 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / digital I/O |
| Pin 11 | RC0/T1OSO/T1CKI/PWM1H — Digital I/O / Timer1 oscillator output / Timer1 clock input / PWM output high-side |
| Pin 12 | RC1/T1OSI/CCP2/PWM1L — Digital I/O / Timer1 oscillator input / CCP2 / PWM output low-side |
| Pin 13 | RC2/CCP1/PWM2H — Digital I/O / CCP1 / PWM output high-side |
| Pin 14 | RC3/SCK/SCL/PWM2L — Digital I/O / SPI clock / I2C clock / PWM output low-side |
| Pin 15 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 16 | RC5/SDO — Digital I/O / SPI data out |
| Pin 17 | RC6/TX/CK — Digital I/O / EUSART transmit / EUSART clock |
| Pin 18 | RC7/RX/DT — Digital I/O / EUSART receive / EUSART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (2.0V to 5.5V) |
| Pin 21 | RB0/AN5/INT0/FLTA — Digital I/O / analog input channel 5 / external interrupt 0 / PWM Fault A |
| Pin 22 | RB1/AN6/INT1 — Digital I/O / analog input channel 6 / external interrupt 1 |
| Pin 23 | RB2/AN7/INT2 — Digital I/O / analog input channel 7 / external interrupt 2 |
| Pin 24 | RB3/AN8/CCP2(2)/PWM3H — Digital I/O / analog input channel 8 / CCP2 alt / PWM output high-side |
| Pin 25 | RB4/PWM3L — Digital I/O / PWM output low-side |
| Pin 26 | RB5/PWM4H — Digital I/O / PWM output high-side |
| Pin 27 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 28 | RB7/PGD — Digital I/O / ICSP data |
Typical Applications
PIC18LF2431T-I/SO is suitable for 7 applications: Sensorless BLDC Motor Control, Switched-Mode Power Supply with PFC, Uninterruptible Power Supply (UPS) Control, Induction Heating Cooktop, Digital Lighting Ballast and LED Driver, Industrial Sensor Interface Hub, Consumer Ceiling Fan and Air-Purifier Drive.
Sensorless BLDC Motor Control
The PIC18LF2431T-I/SO integrates a 14-bit Power Control PWM with up to 6 channels, three 16-bit timers and a 9-channel 10-bit ADC that align perfectly with sensorless BLDC commutation and back-EMF zero-crossing detection. Microchip application note AN1078 ships a production-grade BLDC reference firmware targeting exactly this 28-SOIC part number, using the analog comparators to time back-EMF events and the PWM module to drive the three-phase bridge. The 2.0V to 5.5V VDD window allows the MCU to run from a single 3.3V rail, simplifying sensorless fan, pump and small drone ESC designs.
Recommended
Switched-Mode Power Supply with PFC
The PIC18LF2431T-I/SO's high-resolution Power Control PWM and 10-bit ADC with up to 9 channels make it well-suited to digitally controlled SMPS and power-factor-correction stages. The device drives a PFC MOSFET at the 40 MHz CPU clock, samples the input voltage and current at the ADC and computes the next duty cycle in firmware - implementing average-current-mode control in software. The integrated analog comparators also support cycle-by-cycle current limiting without external circuitry, shrinking the PFC + DC-DC BOM in industrial PSU modules and LED drivers.
Recommended
Uninterruptible Power Supply (UPS) Control
In small UPS and inverter designs the PIC18LF2431T-I/SO acts as the central controller that runs sinusoidal PWM, manages transfer between mains and battery, monitors battery state-of-charge and drives status LEDs. Its 40 MHz CPU and 14-bit PWM deliver a clean sine-wave output from a 12V or 48V battery string with sufficient resolution to keep total harmonic distortion under 5 percent. The Enhanced USART enables a digital display module to read the measured mains frequency, load percentage and battery voltage at 115.2 kbaud for an inexpensive user interface.
Recommended
Induction Heating Cooktop
The PIC18LF2431T-I/SO drives the resonant half-bridge in an induction cooktop and uses the on-chip analog comparators to detect the resonant-capacitor zero-current crossings in real time. The 40 MHz MIPS core is fast enough to compute the next switching period within a few microseconds, maintaining zero-voltage switching across the full load range. The 2.0V to 5.5V supply range supports direct connection to a 5V auxiliary rail commonly used in 220V induction cooking appliances.
Recommended
Digital Lighting Ballast and LED Driver
Fluorescent and HID ballasts as well as high-power LED drivers benefit from the PIC18LF2431T-I/SO's Power Control PWM with programmable dead-band, 10-bit ADC for light-output feedback and Enhanced USART for DALI or 0-10V dimming interfaces. The MCU runs the boost PFC stage plus the downstream buck or half-bridge current regulator in a single chip, reducing ballast cost. Operating from 2.0V to 5.5V lets the ballast share a 5V housekeeping rail with the gate-drive bias supply.
Recommended
Industrial Sensor Interface Hub
In industrial gateways the PIC18LF2431T-I/SO multiplexes 4-20 mA current loops, thermocouples and digital inputs through its 9-channel 10-bit ADC, two analog comparators and 22 I/O. The MSSP (SPI/I2C) drives a downstream display or expansion I/O extender, while the Enhanced USART carries Modbus RTU traffic at 115.2 kbaud back to a PLC. The industrial -40C to +85C operating range, 2.0V to 5.5V supply window and Microchip longevity program make it a safe choice for long-life sensor nodes.
Recommended
Consumer Ceiling Fan and Air-Purifier Drive
BLDC ceiling fans, air-purifier blowers and small kitchen-appliance motors use the PIC18LF2431T-I/SO as the single-chip driver plus user-interface controller. The 22 I/O drive IR remote decoder, push-button speed select, status LEDs and triac/PWM output without external logic. The integrated Power Control PWM and analog comparators implement sensorless trapezoidal commutation, while the wide VDD window lets the design run directly from an 18V rectified mains tap and a 5V regulator.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF2431T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF2431-I/SO | PIC18LF2431-I/SP | PIC18F2431-I/SO | PIC18LF2331-I/SO | PIC18LF4331-I/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SPDIP - same pin count, through-hole | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 16 KB (8K x 16) | 16 KB | 16 KB | 16 KB | 8 KB | 8 KB |
| Data SRAM | 768 bytes | 768 bytes | 768 bytes | 768 bytes | 512 bytes | 512 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| Supply Voltage (VDD) | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 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 |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 |
| Power Control PWM | 14-bit, 6 channels | 14-bit, 6 channels | 14-bit, 6 channels | 14-bit, 6 channels | 14-bit, 6 channels | 14-bit, 8 channels |
| ADC | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels |
| Operating Temperature | -40 C to +85 C (I grade) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Integrated 14-bit Power Control PWM with up to 6 channels (vs PIC18LF23K22-I/SO)
- True 2.0V to 5.5V VDD window on the LF variant (vs PIC18F2431-I/SO)
- Dedicated analog comparators for cycle-by-cycle current limiting (vs PIC18LF4331-I/SO)
- Industrial -40C to +85C operating temperature and long-life Microchip longevity program (vs Generic 8-bit MCU on a different architecture)
Design Notes
The LF variant of PIC18LF2431 runs from 2.0V to 5.5V, so a single 3.3V LDO such as Microchip MCP1700 (250 mA) is sufficient for the MCU rail. Decouple VDD with a 100 nF ceramic placed within 5 mm of pin 20 and a bulk 10 uF tantalum or ceramic on the same net to suppress the inrush current drawn by the internal PLL. Ensure the BOR (Brown-Out Reset) is enabled in the configuration bits so that the part does not run on marginal VDD where the 14-bit PWM output becomes non-linear.
Route the 14-bit Power Control PWM outputs (PWM1H/L, PWM2H/L, PWM3H/L) as short, matched-length traces to the gate-driver inputs and add a 10 ohm to 22 ohm series damping resistor close to the MCU pin to slow the 5V edge into the MOSFET gate. Keep the analog input traces (AN0-AN8) and the digital PWM traces separated by a ground pour or a guard ring around the analog section to keep the 10-bit ADC accuracy within +/- 1 LSB at full 40 MIPS operation.
Estimated: PWM dead-band register updates should be shadow-buffered into the PDC register only at the start of a PWM period to avoid glitches on the power stage. Do not set the PWM time base faster than 120 MHz / 2^14 = ~7.3 kHz without verifying the gate driver can slew at the resulting duty-cycle resolution. Finally, when porting code from PIC18F2431 (4.2V-5.5V) to the LF variant at 3.3V, re-check that the ADC acquisition time and the internal band-gap reference voltage are still within the LF datasheet curves; otherwise current-sense readings in the PFC stage will be biased low.
The 28-SOIC package (0.295 inch / 7.50 mm body width) requires 1.27 mm pitch land pads with 0.6 mm wide solder mask openings. Place the ICSP header on the standard 5-pin Microchip pinout (PGD, PGC, VDD, VSS, MCLR) so the part can be programmed and debugged on-board without removing the MCU. If using the 28-SPDIP adapter (PIC18LF2431-I/SP), reserve a through-hole footprint on the same schematic symbol and let the layout choose either SMT or TH assembly depending on volume.
Compliance Information
RoHS and REACH compliance status reflects Microchip's standard 28-SOIC lead-free finish. Halogen-free status not explicitly listed in the verified web data. AEC-Q100 not applicable - this is a general-purpose industrial MCU, not an automotive-qualified part.
