PIC18F2331T-I/MM - 8-bit MCU, 8KB Flash, 22 I/O | Microchip
MPN: PIC18F2331T-I/MM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.68 | $46.80 |
| 100 | $4.16 | $416.00 |
| 500 | $3.74 | $1,870.00 |
| 1,000 | $3.32 | $3,320.00 |
PIC18F2331T-I/MM Overview
Background Knowledge. An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path and Harvard or modified-Harvard architecture, typically used for embedded control tasks such as sensor reading, actuator driving, and serial protocol handling. Within the broader taxonomy, the PIC18F2331T-I/MM belongs to: 8-bit MCU -> PIC microcontroller -> PIC18 family -> PIC18F2331 sub-family. PIC18 devices are mid-range 8-bit MCUs optimized for high computational throughput at low cost, commonly used for motor control, lighting, and small appliances.
Key features include the nanoWatt power-management technology for active and sleep current optimization, a wide 2.0 V to 5.5 V operating voltage range, two analog comparators, two CCP/ECCP modules, a hardware QEI block, an 8 MHz internal oscillator, and 256 bytes of EEPROM. The 40 MHz operation supports 10 MIPS throughput, which is more than adequate for closed-loop motor commutation routines. The 28-QFN-S package includes an exposed pad for thermal dissipation, beneficial when driving MOSFET gate drivers with sustained PWM activity.
Typical applications include brushless DC (BLDC) and permanent-magnet synchronous motor (PMSM) control, sensorless and sensored fan control, small industrial pumps, low-cost variable-frequency drives, LED lighting controllers, and any 5 V embedded platform that needs deterministic PWM at high update rates. Peripherals such as the QEI and CCP form the core of field-oriented-control (FOC) firmware reference designs.
Design consideration. When designing with the PIC18F2331T-I/MM, route the high-current switching traces (PWM outputs, gate driver return paths) away from the analog A/D inputs to minimize ground bounce coupling. Use the exposed thermal pad with a continuous ground pour for thermal relief, and follow Microchip's recommended 100 nF decoupling network on each VDD pin to prevent MCU brown-out during MOSFET switching transients.
Unique value. This page synthesizes distributor pricing, drop-in alternatives from the same PIC18F2331 family, and practical design notes not consolidated in any single Microchip datasheet or distributor listing.
Drop-in alternatives for PIC18F2331T-I/MM — 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 PIC18F2331T-I/MM (same form factor and footprint) — differing in ADC, Maximum CPU Speed, Operating Temperature, Package, Supply Voltage.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2331-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2331-E/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2431-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
DSPIC33FJ128MC202-I/MM
✅ Drop-In✓ In Stock
$3.55 / Unit
View Datasheet →PIC18F2331T-I/MM Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Maximum CPU Speed | 40 MHz |
| Program Memory Type | FLASH |
| Program Memory Size | 8 KB (4K x 16) |
| RAM Size | 768 B |
| EEPROM Size | 256 B |
| Number of I/O Pins | 22 |
| Supply Voltage | 2.0 V to 5.5 V |
| ADC | 10-bit, up to 5 channels |
| Connectivity | I2C, SPI, UART/USART |
| PWM Modules | ECCP + Power Control PWM |
| Quadrature Encoder (QEI) | Yes |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-QFN-S (6x6 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Internal Oscillator | 8 MHz |
PIC18F2331T-I/MM 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 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| 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 | OSC1/CLKIN/RA7 — Crystal input / External clock / PORTA bit 7 |
| Pin 11 | OSC2/CLKOUT/RA6 — Crystal output / Clock out / PORTA bit 6 |
| Pin 12 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 13 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 14 | RC2/CCP1 — PORTC bit 2 / Enhanced CCP1 |
| Pin 15 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 16 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 17 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 18 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 19 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 20 | RB0/INT0/FLTA — PORTB bit 0 / External INT0 / PWM fault A |
| Pin 21 | RB1/INT1 — PORTB bit 1 / External INT1 |
| Pin 22 | RB2/INT2 — PORTB bit 2 / External INT2 |
| Pin 23 | RB3/INT3 — PORTB bit 3 / External INT3 |
| Pin 24 | RB4/QEA — PORTB bit 4 / QEI phase A |
| Pin 25 | RB5/QEB — PORTB bit 5 / QEI phase B |
| Pin 26 | RB6/INDX/PGC — PORTB bit 6 / QEI index / ICSP clock |
| Pin 27 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 28 | VDD — Digital supply voltage |
Typical Applications
PIC18F2331T-I/MM is suitable for 7 applications: Sensorless BLDC Fan Control, Sensored PMSM Servo Drive, Variable-Frequency Refrigerator Compressor Drive, Industrial PWM LED Lighting Controller, Low-Cost Automotive Body Electronics, Small Industrial Pump Controller, Smart Fan and HVAC Blower Control.
Sensorless BLDC Fan Control
The PIC18F2331T-I/MM is a strong fit for 12 V / 24 V sensorless BLDC fan controllers in PC cooling, server fans, and appliance blowers. Its Power Control PWM module supports complementary 3-phase outputs with programmable dead time at up to 20 kHz, while the 10-bit ADC samples back-EMF at the correct zero-crossing window for trapezoidal commutation. The 8 KB Flash is sufficient for Microchip's AN1083 sensorless BEMF reference firmware, and the 768 B RAM holds the state machine plus back-EMF filter coefficients. Compared with discrete analog designs, this part reduces BOM by integrating the oscillator, comparators, and gate-driver logic on a single 28-QFN-S die.
Recommended
Sensored PMSM Servo Drive
For sensored PMSM drives such as CNC spindle motors, robotic joints, and pump controllers, the PIC18F2331T-I/MM's QEI block decodes the optical encoder A/B/index signals in hardware, offloading the CPU. The ECCP module drives the 3-phase inverter MOSFETs, and the 10-bit ADC reads the shunt-resistor current for torque control. With 40 MHz (10 MIPS) throughput, the device runs 10 kHz torque-loop firmware without timing jitter. The wide 2.0 V to 5.5 V supply supports direct 3.3 V sensor connection and 5 V gate driver interfaces, while the 28-QFN-S package fits in compact integrated motor modules.
Recommended
Variable-Frequency Refrigerator Compressor Drive
Inverter-driven refrigerator compressors use the PIC18F2331T-I/MM to implement sensorless sinusoidal or trapezoidal commutation at compressor speeds from 1500 to 4500 RPM. The Power Control PWM can be synchronized to the ADC, allowing precise current sampling at the center of the PWM pulse. The 2.0 V to 5.5 V supply range simplifies the auxiliary rail design from a high-voltage PFC bus, and the nanoWatt sleep modes drop quiescent current below 100 nA in standby, helping appliances meet IEC 60335-1 standby-power limits. The 22 I/O pins provide UART for diagnostics and GPIO for safety inputs.
Recommended
Industrial PWM LED Lighting Controller
Industrial and architectural LED dimmers from 1 A to 5 A per channel can use the PIC18F2331T-I/MM as the digital control core. The Power Control PWM delivers high-resolution dimming with up to 14-bit PWM duty cycle at low frequencies, eliminating visible flicker. The 10-bit ADC reads photodiode or 0-10 V analog dim inputs, while the UART provides DMX-512 or DALI bridge connectivity. The 2.0 V to 5.5 V supply accepts PoE or 24 V industrial rails directly through a linear regulator, and the 28-QFN-S package enables slim in-fixture designs. Engineers targeting tunable-white systems benefit from the dual-CCP for independent warm/cool channels.
Recommended
Low-Cost Automotive Body Electronics
While not AEC-Q100 qualified, the PIC18F2331T-I/MM is widely used in non-safety automotive body modules such as seat-position actuators, mirror adjusters, and accessory lighting, where the -40C to +85C industrial grade suffices for cabin environments. The 22 I/O pins drive multiple low-side relays and read Hall-effect sensors. The hardware QEI supports wiper-position feedback, and the UART links to a body-control master via LIN. Its 8 KB Flash fits state-machine firmware plus LIN 1.x slave protocol stacks. Designers needing AEC-Q100 should select a PIC18 K-series Q1 variant; the PIC18F2331T-I/MM is positioned for non-safety automotive body applications.
Recommended
Small Industrial Pump Controller
Dosing pumps, peristaltic pumps, and small centrifugal pumps under 200 W use the PIC18F2331T-I/MM to regulate flow via sensorless or sensored BLDC/PMSM control. The hardware QEI decodes paddlewheel or magnetic flow-meter pulses, while the ECCP drives the motor inverter. The 10-bit ADC reads pressure or level sensors for closed-loop control, and the UART connects to an HMI display or RS-485 network. Industrial temperature grade (-40C to +85C) supports outdoor cabinet installations, and the nanoWatt sleep modes reduce quiescent draw in intermittent-duty pump systems.
Recommended
Smart Fan and HVAC Blower Control
HVAC blowers, ventilation fans, and refrigeration evaporator fans benefit from the PIC18F2331T-I/MM's 3-phase PWM and ADC synchronization. Closed-loop RPM control via back-EMF or Hall sensors reduces noise and saves energy versus AC induction drives. The 22 I/O drive the 3-phase inverter plus discrete MOSFET gate drivers for high-side N-FET bootstrap control, and the SPI port connects to a digital temperature/humidity sensor for closed-loop airflow regulation. Industrial temperature grade and the 28-QFN-S package fit standard HVAC control-board footprints, while the 2.0 V to 5.5 V supply accepts 24 V HVAC rails through a simple LDO.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2331T-I/MM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2331-I/MM | PIC18F2331-E/MM | PIC18F2431-I/MM | DSPIC33FJ128MC202-I/MM |
|---|---|---|---|---|---|
| Package | 28-QFN-S (6x6 mm) | 28-QFN-S (6x6 mm) | 28-QFN-S (6x6 mm) | 28-QFN-S (6x6 mm) | 28-QFN-S (6x6 mm) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | PIC 8-bit | PIC 8-bit | PIC 8-bit | PIC 8-bit | dsPIC 16-bit DSP |
| Max CPU Speed | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (20 MIPS) |
| Flash Memory | 8 KB | 8 KB | 8 KB | 16 KB | 16 KB |
| RAM | 768 B | 768 B | 768 B | 1 KB | 2 KB |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 0 B (emulated) |
| I/O Pins | 22 | 22 | 22 | 22 | 21 |
| QEI Block | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +125C | -40C to +85C | -40C to +85C |
Key Differentiators
- Hardware QEI block for encoder feedback (vs PIC18F2331-I/SO)
- Industrial -40C to +85C temperature grade (vs DSPIC33FJ128MC202-I/MM)
- Power Control PWM with hardware fault input (vs PIC18F2431-I/MM)
Design Notes
Estimated: at maximum CPU activity (40 MHz, peripherals active) the PIC18F2331T-I/MM dissipates approximately 60 mW from the 5 V supply. The 28-QFN-S exposed pad must be soldered to a continuous ground pour, sized at minimum 50 mm^2, to keep junction temperature below 70C in a typical +25C ambient. For motor-control applications where the MCU sits near switching power stages, isolate the MCU thermal pad with a cutout in the high-current copper pour to reduce ground-bounce injection into the analog AVSS pin.
Place a 100 nF ceramic decoupling capacitor within 3 mm of each VDD/AVDD pin, and a bulk 10 uF tantalum or ceramic capacitor at the supply entry point. The AVDD and AVSS pins must each have their own 100 nF capacitor to isolate analog reference from digital switching noise. If the ADC VREF+ is sourced externally, add a 10 uF buffer capacitor directly at the VREF+ pin; do not rely on the VDD rail for ADC accuracy above 8-bit. Brown-out reset thresholds should be configured (BOREN = enabled) for the specific battery or rail profile.
Route the PWM output traces (PWM1H/L through PWM3H/L) as a tightly coupled 3-phase group on the top layer, with the gate-driver return path on the immediate layer below. Keep analog A/D traces (AN0-AN5) and the QEI signals (QEA, QEB, INDX) away from PWM switching edges; route them on a separate layer with grounded guard traces around the analog signals. The ICSP pins (PGC/PGD) must be accessible for in-circuit programming; do not place large capacitors on these pins that would block programming pulses.
Do not assume the 28-QFN-S package can be hand-soldered reliably; reflow with a hot plate or reflow oven is mandatory. The exposed pad must be soldered; missing-pad solder joints cause thermal runaway and electrical reset glitches. When migrating from PIC18F2331-I/SO (28-SOIC) to PIC18F2331T-I/MM (28-QFN), the pinout is identical electrically but the QFN package has different pad geometry - the land pattern must follow IPC-7351 nominal or the Microchip recommended footprint. Finally, the OSC1/OSC2 pins require careful layout when using a crystal: keep traces short and surround with a grounded guard ring.
Compliance Information
RoHS compliance and lead-free status confirmed from the Microchip product page. AEC-Q100 qualification is not available for this part; for automotive safety applications, select a K-series Q1 variant. Halogen-free status is not explicitly stated in the verified web data and is listed as unknown.
