PIC18F2431-E/SO - 8-bit MCU, 16KB Flash, 40MHz, 28-SOIC | Microchip
MPN: PIC18F2431-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.3438 | $7.34 |
| 10 | $6.55 | $65.50 |
| 100 | $5.42 | $542.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.21 | $4,210.00 |
PIC18F2431-E/SO Overview
A PIC18 microcontroller is an 8-bit RISC flash MCU from Microchip’s PIC18F family, sitting between the PIC16 baseline and the PIC24/dsPIC architectures. PIC18 cores use a 16-bit instruction word with an 8-bit data path, deliver up to 16 MIPS throughput, and are programmed using the MPLAB X IDE with the XC8 compiler. They form the backbone of cost-sensitive embedded designs that need deterministic real-time control, on-chip flash, and rich peripherals. Positioned in the broader taxonomy, PIC18 belongs to 8-bit microcontrollers, under microcontrollers, under microprocessors and microcontrollers, under integrated circuits, under semiconductors.
Key differentiating features of the PIC18F2431-E/SO include the 14-bit enhanced PWM with dedicated time-base and duty-cycle registers, true 10-bit ADC with acquisition timing, and nanoWatt power-saving modes such as Sleep, Idle, and oscillator switching. The 28-SOIC package provides easy hand-soldering and breadboarding for prototypes while still being surface-mountable for production.
Architecturally, the PIC18F2431 uses a Harvard RISC core with hardware multiply, an internal 8 MHz oscillator (calibrated), and a separate 16-level hardware stack. The 14-bit PWM is purpose-built for motor control and power conversion, complementing the PIC18F2331 (smaller flash) in the same family.
Typical applications include BLDC and PMSM motor control (the part’s headline use case), HVAC blowers, small pumps, LED lighting drivers, industrial sensor interfaces, and general-purpose 8-bit embedded control. In each, the integrated high-resolution PWM eliminates the need for an external motor-control ASIC.
Design consideration: ensure the 4.2 V minimum supply is met under worst-case brownout conditions, and that unused I/O pins are configured as outputs (or inputs with the weak pull-up enabled) to minimize Sleep-mode current. Place VDD/VSS decoupling 100 nF + bulk capacitors within a few mm of the package.
This page synthesizes distributor pricing, drop-in 28-SOIC alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F2431-E/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 PIC18F2431-E/SO (same form factor and footprint) — differing in Core Architecture, I/O Pins, Package, MSL Level, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2431-I/SO
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC18F2331-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2431T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2321-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F23K22-I/SO
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F2431-E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 RISC, 8-bit data path |
| Instruction Set | PIC18 (16-bit instruction word) |
| Program Flash Memory | 16 KB (8K x 16 words) |
| SRAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Clock | 40 MHz |
| Performance | 16 MIPS @ 40 MHz |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 22 |
| ADC | 10-bit, up to 9 channels |
| PWM | 14-bit enhanced, up to 6 channels |
| Timers | Three 16-bit timers/counters |
| Communication | 1x USART, 1x MSSP (SPI/I2C) |
| Analog Comparators | 2 |
| Operating Temperature | -40 °C to +125 °C (E grade) |
| Package | 28-SOIC (0.295"/7.50 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Programming | ICSP (In-Circuit Serial Programming) |
PIC18F2431-E/SO Pin Configuration
| Pin 1 | MCLR/RE3 — Reset input / digital input only |
| 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 | VSS — Ground reference |
| Pin 9 | OSC1/RA7 — Crystal input / digital I/O |
| Pin 10 | OSC2/RA6 — Crystal output / digital I/O |
| Pin 11 | RC0/T1CKI — Digital I/O / Timer1 clock input |
| Pin 12 | RC1 — Digital I/O |
| Pin 13 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 14 | RC3 — Digital I/O |
| Pin 15 | RC4 — Digital I/O |
| Pin 16 | RC5 — Digital I/O |
| Pin 17 | RC6/TX — Digital I/O / USART TX |
| Pin 18 | RC7/RX — Digital I/O / USART RX |
| Pin 19 | VSS — Ground |
| Pin 20 | VDD — Positive supply |
| Pin 21 | RB0/INT0 — Digital I/O / external interrupt 0 |
| Pin 22 | RB1/INT1 — Digital I/O / external interrupt 1 |
| Pin 23 | RB2 — Digital I/O |
| Pin 24 | RB3 — Digital I/O |
| Pin 25 | RB4 — Digital I/O |
| Pin 26 | RB5 — Digital I/O |
| Pin 27 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 28 | RB7/PGD — Digital I/O / ICSP data |
Typical Applications
PIC18F2431-E/SO is suitable for 6 applications: BLDC / PMSM Motor Control, HVAC Fan and Blower Control, Small Pumps and Fluid Handling, LED Lighting Drivers, Industrial Sensor Interfaces, General-Purpose 8-bit Embedded Control.
BLDC / PMSM Motor Control
The PIC18F2431-E/SO is purpose-built for sensorless and sensored 3-phase BLDC and PMSM motor control. Its 14-bit enhanced PWM delivers 6 complementary outputs with programmable dead-time and center-aligned mode, which matches the commutation requirements of 3-phase bridges; a 10-bit ADC with up to 9 channels samples back-EMF or phase current at the switching frequency. The 40 MHz/16 MIPS PIC18 core executes field-oriented control firmware at 16 kHz with margin to spare, while the 16 KB flash and 768 B SRAM fit typical FOC state machines. Integrated analog comparators provide hardware overcurrent protection within microseconds, faster than ADC-based trips. For 24 V brushless fans, pumps, and small drones this part removes the need for a dedicated motor-control ASIC and keeps the BOM to one chip plus a gate driver.
Recommended
HVAC Fan and Blower Control
Variable-speed HVAC blowers need quiet, energy-efficient switching at low RPM. The PIC18F2431-E/SO's 14-bit PWM enables fine-grained duty-cycle control below 1% resolution, eliminating audible switching artifacts in fan motors, while nanoWatt Sleep and Idle modes drop quiescent current during standby. The 22 I/O pins handle tachometer feedback, temperature sensors, and a 10-bit ADC for closed-loop RPM regulation. Operating from 4.2 V to 5.5 V lets the MCU share a common 5 V rail with the gate driver, and the Extended -40 °C to +125 °C grade survives hot-plenum installations. Compared with PIC18F2420 the enhanced PWM is the deciding factor for sinusoidal commutation schemes that reduce acoustic noise.
Recommended
Small Pumps and Fluid Handling
Peristaltic and centrifugal dosing pumps need precise PWM speed control to maintain flow accuracy. The PIC18F2431-E/SO's 14-bit PWM and 16 MIPS throughput run PID flow loops with 1 ms update rates, while the 10-bit ADC reads flow-meter pulses converted via analog comparators. Its Extended temperature grade allows deployment in outdoor or under-hood environments, and 22 I/O pins handle multiple control buttons, LED indicators, and RS-485 communication for fleet monitoring. The PIC18F2431-E/SO replaces discrete analog pump controllers with a programmable, calibration-capable digital solution.
Recommended
LED Lighting Drivers
High-end architectural LED drivers benefit from the PIC18F2431-E/SO's 14-bit PWM to support 16 million dimming steps with smooth logarithmic dimming curves that match human eye response. The 10-bit ADC reads ambient light sensors for daylight harvesting, while the MSSP (SPI/I2C) port drives constant-current LED controllers such as the TLC5941. The wide 4.2 V to 5.5 V input range accepts boost-converter outputs, and nanoWatt modes reduce standby power below 1 µA when the fixture is off. Compared with simpler PIC16 parts the PIC18F2431-E/SO adds headroom for color-mixing firmware on RGBW fixtures.
Recommended
Industrial Sensor Interfaces
Industrial 4-20 mA sensor transmitters and bridge sensor conditioners use the PIC18F2431-E/SO to digitize analog signals and present them on a USART or SPI bus. The 10-bit ADC with up to 9 channels multiplexes thermocouple, RTD, and pressure signals through a single chip, while 16 KB flash hosts linearization tables for sensor compensation. The Extended -40 °C to +125 °C grade and 28-SOIC footprint suit DIN-rail transmitter modules where PCB area is tight. The MSSP peripheral drives isolated SPI or I2C transceivers to the host PLC.
Recommended
General-Purpose 8-bit Embedded Control
Beyond motor control the PIC18F2431-E/SO serves any cost-sensitive embedded application that needs 16 KB flash, USART, MSSP, three 16-bit timers, and 22 I/O in a small SOIC. Typical uses include vending-machine controllers, access-control keypads, simple HMI panels, and battery chargers with CC/CV profiles generated by the 14-bit PWM. The PIC18 core's deterministic 4-clock-per-instruction timing simplifies assembly-level interrupt handling for real-time I/O. This breadth makes the part a strong default when the design needs more memory and peripherals than a PIC16 can offer, but does not justify stepping up to a PIC24 or dsPIC.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2431-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2431-I/SO | PIC18F2331-I/SO | PIC18F2431T-I/SO | PIC18F2420-I/SO | PIC18F2321-I/SO | PIC18F23K22-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC (0.295 inch) | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same | 28-SOIC (0.295 inch) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 8 KB (-50%) | 16 KB | 16 KB | 8 KB (-50%) | 8 KB (-50%) |
| SRAM | 768 B | 768 B | 768 B | 768 B | 768 B | 512 B (-33%) | 512 B (-33%) |
| Maximum Clock | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 64 MHz (+60%) |
| Enhanced PWM | 14-bit, 6 outputs | 14-bit, 6 outputs | 14-bit, 6 outputs | 14-bit, 6 outputs | No enhanced PWM (10-bit CCP) | No enhanced PWM (10-bit CCP) | No 14-bit enhanced (CCP PWM) |
| ADC | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 9 channels | 10-bit, 10 channels | 10-bit, 7 channels | 10-bit, 11 channels |
| Temperature Grade | Extended -40 to +125 C | Industrial -40 to +85 C | Industrial -40 to +85 C | Industrial -40 to +85 C | Industrial -40 to +85 C | Industrial -40 to +85 C | Industrial -40 to +85 C |
Key Differentiators
- Highest-temperature 16 KB flash variant in the family (vs PIC18F2431-I/SO)
- Twice the flash of PIC18F2331 at same price tier (vs PIC18F2331-I/SO)
- Integrated 14-bit enhanced PWM eliminates external motor-control ASIC (vs PIC18F2420-I/SO)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 20), plus a 10 µF bulk capacitor on the same rail within 25 mm. The PIC18F2431-E/SO draws up to 16 mA at 40 MHz, so the bulk cap must supply switching transients without dipping VDD below 4.2 V. For motor-control boards with high di/dt from gate drivers, add a ferrite bead between the digital 5 V and the analog VDD/VREF+ rail to suppress switching noise on the ADC reference.
Unused I/O pins should be configured as outputs driving low, not left as floating inputs. Floating inputs draw extra current in Sleep mode and can trigger spurious interrupts via the INT0/INT1 lines. If the design intentionally uses an analog pin as digital I/O, disable the analog channel in the ANSEL register. The 28-SOIC pinout shares pins with the ICSP PGC/PGD (RB6/RB7), so a programming header must not interfere with the application circuit on those lines.
Keep crystal traces on OSC1/OSC2 short (<10 mm), surrounded by a ground guard ring, and place the load capacitors within 5 mm of the pins. For motor-control boards, route the PWM outputs (CCP1, PWM1-3) and analog ground (VSS analog) on separate traces that meet only at the chip's VSS pin. This reduces switching-noise coupling into ADC readings and back-EMF samples.
At 40 MHz CPU clock the PIC18F2431-E/SO dissipates approximately 250 mW in continuous operation, well within the 28-SOIC's ~80 °C/W theta-JA thermal resistance for typical 4-layer boards. No heatsink is required, but in enclosed motor-control enclosures above 60 °C ambient, derate the clock to 32 MHz or add a small copper pour under the exposed GND pins (1/3/8/19) to drop theta-JA by 10-15 °C/W.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; the automotive grade equivalent is the PIC18F2431-E/SO with no separate Q1 suffix because the E temperature grade is the highest available. Lead-free 28-SOIC matte-tin plating. REACH and conflict-minerals statements available on Microchip's environmental compliance page.
