PIC18LF2331T-I/ML - 8KB Flash 8-bit MCU, 40MHz, 28-VQFN | Microchip
MPN: PIC18LF2331T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.5 | $4.50 |
| 10 | $4.05 | $40.50 |
| 100 | $3.6 | $360.00 |
| 500 | $3.2 | $1,600.00 |
| 1,000 | $2.85 | $2,850.00 |
PIC18LF2331T-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash/ROM), volatile data memory (SRAM), and a rich set of peripherals on one silicon die. The PIC18 family uses an enhanced RISC Harvard architecture with 16-bit opcodes and an 8-bit data path, sitting in the mid-tier of Microchip's PIC portfolio above the baseline PIC10/12/16 families. The PIC18LF2331T-I/ML belongs to the PIC18F2x31 sub-family, which adds an 8-channel 10-bit ADC, an enhanced 8-bit PWM module with up to 6 channels, two CCP modules, an MSSP port for SPI/I2C, and a USART for asynchronous serial communication. This hierarchy (8-bit MCU -> PIC microcontroller -> RISC microcontroller -> embedded controller -> semiconductor) makes the part a strong fit for compact, mixed-signal, low-power embedded designs.
Key features of the PIC18LF2331T-I/ML include 22 digital I/O pins, a 10-bit ADC with up to 8 channels, hardware PWM with programmable dead-band control suitable for motor-drive and power-conversion loops, an internal 8 MHz oscillator with PLL option, an ICD/ICSP debug header, and four timer modules (Timer0/1/2/3). Its nanoWatt Technology provides several software-selectable power-managed modes - Primary RC, Primary Crystal, and Secondary Oscillator - allowing the CPU core and peripherals to be clock-gated independently. Brown-out Reset (BOR), Watchdog Timer (WDT) with on-chip low-power oscillator, and Power-on Reset (POR) are built in.
Typical applications for the PIC18LF2331T-I/ML include brushless DC (BLDC) and brushed DC motor control loops, sensor-fan and pump controllers, small appliance and white-goods subsystems, sensor-signal conditioning front-ends, and battery-powered IoT sensor nodes where its low-voltage LF core and QFN-28 footprint minimize board area. The integrated Motion Feedback Module (MFM) on this family can simplify Hall-sensor or BEMF signal decoding for sensored BLDC commutation. In the system hierarchy, it typically sits between a sensor / power-driver stage and the host processor, running real-time control firmware from on-chip Flash.
When designing with this device, pay attention to the QFN-28 exposed pad - it must be soldered to a sufficiently large copper pour for thermal dissipation and electrical grounding. Decoupling should place 100nF and 10uF caps close to VDD/VSS, and the ICSP/ICD pins must be reserved for in-circuit programming. Pair the MCU with a Microchip TC4427 or TC427 driver if the PWM outputs need to drive power MOSFETs directly.
This page combines distributor pricing, drop-in same-package alternatives, and application guidance - a synthesis not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18LF2331T-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 PIC18LF2331T-I/ML (same form factor and footprint) — differing in ADC, Communication, I/O Pins, MSL Level, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2331T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2331-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2431T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.05 / Unit
View Datasheet →PIC18LF2331T-I/SO
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18LF2331T-I/MM
✅ Drop-In✓ In Stock
$3.18 / Unit
View Datasheet →PIC18LF2331T-I/ML Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core | PIC18 enhanced RISC (Harvard) |
| Program Memory (Flash) | 8 KB (4K x 16 words) |
| Data Memory (SRAM) | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Operating Voltage (VDD) | 2.0 V to 3.6 V (LF core) |
| I/O Pins | 22 digital I/O |
| ADC | 10-bit, up to 8 channels |
| PWM Modules | Enhanced 8-bit PWM, up to 6 channels |
| CCP Modules | 2 |
| Timers | 4 (Timer0, Timer1, Timer2, Timer3) |
| Communication | MSSP (SPI/I2C), USART |
| Package | 28-VQFN (ML) with exposed pad, 6x6 mm |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial) |
| Power-Saving Modes | nanoWatt Technology (Primary RC, Primary XTL, Secondary OSC) |
| Special Features | Motion Feedback Module (MFM), BOR, WDT, POR, ICSP/ICD |
| MSL Level | MSL3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC18LF2331T-I/ML Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input or digital-only RE3 input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| Pin 6 | RA4/AN4 — PORTA bit 4 / analog input 4 (open-drain output) |
| Pin 7 | RA5/AN5 — PORTA bit 5 / analog input 5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7 — PORTA bit 7 (digital only) |
| Pin 10 | RA6 — PORTA bit 6 / oscillator I/O |
| Pin 11 | RC0 — PORTC bit 0 / PWM output |
| Pin 12 | RC1 — PORTC bit 1 / PWM output |
| Pin 13 | RC2 — PORTC bit 2 / PWM output |
| Pin 14 | RC3 — PORTC bit 3 / SPI/I2C clock |
| Pin 15 | RC4 — PORTC bit 4 / SPI/I2C data |
| Pin 16 | RC5 — PORTC bit 5 / SPI/I2C or PWM |
| Pin 17 | RC6 — PORTC bit 6 / USART TX |
| Pin 18 | RC7 — PORTC bit 7 / USART RX |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply 2.0V-3.6V (LF) |
| Pin 21 | RB0 — PORTB bit 0 / interrupt-on-change |
| Pin 22 | RB1 — PORTB bit 1 / interrupt-on-change |
| Pin 23 | RB2 — PORTB bit 2 / interrupt-on-change |
| Pin 24 | RB3 — PORTB bit 3 / interrupt-on-change / PGM |
| Pin 25 | RB4 — PORTB bit 4 / interrupt-on-change |
| Pin 26 | RB5 — PORTB bit 5 / interrupt-on-change / PGD |
| Pin 27 | RB6 — PORTB bit 6 / PGC (ICSP clock) |
| Pin 28 | RB7 — PORTB bit 7 / PGD (ICSP data) |
| Pin EP | Exposed Pad (EP) — Thermal/ground pad - must be soldered to GND pour |
Typical Applications
PIC18LF2331T-I/ML is suitable for 6 applications: Brushless DC (BLDC) Motor Control, Sensor Fan and Pump Controllers, Small Appliance and White-Goods Subsystems, Battery-Powered IoT Sensor Nodes, Automotive Circuit Protection, Industrial Sensor Signal Conditioning.
Brushless DC (BLDC) Motor Control
The PIC18LF2331T-I/ML is purpose-built for low-voltage sensored BLDC commutation. Its integrated Motion Feedback Module (MFM) decodes Hall-sensor or BEMF signals directly, while the enhanced PWM module with programmable dead-mode holds six complementary outputs that drive a 3-phase inverter, all sampled at a 40 MHz / 10 MIPS rate. The 2.0-3.6V VDD lets designers run the MCU and gate logic from a 3.3V LDO fed by a 12V buck, removing a redundant 5V rail. Compared to a discrete comparator-based front-end, the MFM shrinks the BOM by 4-6 components and keeps commutation latency below 4 microseconds at 40 MHz CPU clock.
Recommended
Sensor Fan and Pump Controllers
Small-sensor cooling fans, CPU heatsink fans, and miniature liquid pumps benefit from the PIC18LF2331T-I/ML's LF 2.0-3.6V supply and low nanoWatt sleep current. The 8-channel 10-bit ADC reads tachometer, thermistor, and current-sense inputs simultaneously, while two CCP modules generate the variable-frequency PWM needed for closed-loop RPM control. Industrial-grade -40C to +85C operation ensures reliability in fan hubs near heat sources. A typical design pairs the MCU with a TC427 half-bridge driver and MCP1700 LDO; total BOM cost lands well under $2 in volume.
Recommended
Small Appliance and White-Goods Subsystems
Inside a washing-machine pump driver, dishwasher circulation pump, or rice-cooker thermal loop, the PIC18LF2331T-I/ML provides the control brain at low cost. The 28-VQFN (ML) 6x6 mm package fits compact appliance boards, and 22 I/O pins drive multiplexed LED indicators, keypads, and triac-control optocouplers through the USART and MSSP ports. Flash self-programming via ICSP allows field firmware upgrades through the appliance service port without opening the enclosure, while the BOR/WDT/POR trio handles brown-out events during compressor inrush.
Recommended
Battery-Powered IoT Sensor Nodes
The PIC18LF2331T-I/ML's 2.0V minimum VDD lets it run directly from two AA alkaline cells down to their end-of-life cutoff, while nanoWatt sleep modes drop quiescent current to microamp levels between sensor reads. The 768-byte SRAM and 256-byte EEPROM provide local buffering for periodic sensor telemetry, and the USART links to a sub-GHz or BLE module such as the MRF24J40 or RN4870 for uplink. Industrial -40C to +85C operation handles outdoor deployments. A 3xAA pack can deliver roughly 3-5 years of battery life at 1 wake/minute, depending on duty cycle.
Recommended
Automotive Circuit Protection
The PIC18LF2331T-I/ML's industrial -40C to +85C rating and robust ESD performance make it a candidate for non-safety automotive subsystems such as seat-heater controllers, mirror adjusters, and ambient lighting drivers. The enhanced PWM with hardware dead-time generates clean 100 Hz to 25 kHz PWM for LED dimming without software jitter, and the MSSP port talks to I2C-controlled LED drivers like the MCP2221. Note: the LF part is not AEC-Q100 qualified; for AEC-Q100-grade BLDC fan control in cabin ventilation, the PIC18F2331T-I/ML Q1-grade equivalent is recommended instead.
Recommended
Industrial Sensor Signal Conditioning
In a 4-20 mA loop-powered sensor or strain-gauge bridge front-end, the PIC18LF2331T-I/ML digitizes the conditioned signal via its 10-bit ADC and linearizes it through look-up tables in Flash. The 8 KB of program memory holds calibration curves, while the 256-byte EEPROM retains user-set coefficients across power cycles. The USART delivers digital output to a Modbus RTU master or local HMI, and the ICSP debug port lets field engineers re-calibrate without removing the sensor head. The 2.0-3.6V LF range matches loop-powered 3.3V-derived supplies directly.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF2331T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2331T-I/ML | PIC18LF2331-I/ML | PIC18LF2431T-I/ML | PIC18LF2331T-I/SO | PIC18LF2331T-I/MM |
|---|---|---|---|---|---|---|
| Package | 28-VQFN (ML) 6x6 mm | 28-VQFN (ML) - same | 28-VQFN (ML) - same | 28-VQFN (ML) - same | SOIC-28 wide body (SO) - different | 28-VQFN (MM) alternate outline - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Operating Voltage (VDD) | 2.0 V to 3.6 V (LF) | 4.2 V to 5.5 V (F) | 2.0 V to 3.6 V (LF) - same | 2.0 V to 3.6 V (LF) - same | 2.0 V to 3.6 V (LF) - same | 2.0 V to 3.6 V (LF) - same |
| Flash Program Memory | 8 KB | 8 KB - same | 8 KB - same | 16 KB (+100%) | 8 KB - same | 8 KB - same |
| SRAM | 768 B | 768 B - same | 768 B - same | 768 B - same | 768 B - same | 768 B - same |
| Maximum CPU Speed | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same | 40 MHz / 10 MIPS - same |
| I/O Pins | 22 | 22 - same | 22 - same | 22 - same | 22 - same | 22 - same |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels - same | 10-bit, 8 channels - same | 10-bit, 8 channels - same | 10-bit, 8 channels - same | 10-bit, 8 channels - same |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same |
| Approximate Unit Price (qty 1) | $4.50 | $4.50 (similar) | $4.50 (similar) | $5.00 (approx) | $4.30 (similar) | $4.50 (similar) |
Key Differentiators
- Integrated Motion Feedback Module (MFM) for sensored BLDC commutation (vs PIC18LF2221T-I/ML (PIC18F2221 28-VQFN))
- Low-voltage LF operation down to 2.0V (vs PIC18F2331T-I/ML (F-variant, 4.2-5.5V))
- Industrial -40C to +85C rating with 8 KB Flash (vs PIC18F13K50-I/MQ (28-QFN, 8 KB, 5V only))
Design Notes
The 28-VQFN (ML) package's exposed thermal pad (EP) on the underside MUST be soldered to a continuous ground copper pour of at least 25 mm^2 (a 5x5 mm island of 1 oz copper) to keep junction temperature within the -40C to +85C industrial range. Estimated: theta_JA on the recommended JEDEC EIA/JESD51 4-layer test board is approximately 30 C/W for this package; at full CPU load (10 MIPS, all peripherals active) the part dissipates ~50 mW, giving a 1.5 C temperature rise above ambient - well within safe limits when the EP is properly soldered.
Place a 100 nF X7R ceramic decoupling capacitor as close as possible to each VDD/VSS pair (pads 8-9-19-20 region on the QFN), and add a bulk 10 uF X5R cap on the same net within 5 mm of the MCU. For the ICSP/ICD debug pins (RB6/PGC and RB7/PGD, pads 27-28), route them directly to a 6-pin header with no series resistors or series components; the MPLAB ICD programmer requires a clean connection during debug sessions.
Do not power the PIC18LF2331T-I/ML with a 5V supply - the LF variant has an absolute maximum VDD of 3.6V and will be damaged. If your system bus is 5V, choose the F-variant PIC18F2331T-I/ML instead, which has the same 28-VQFN (ML) footprint. Also, when migrating from the F to LF variant, verify that all I/O pin pull-ups are sized for 3.3V logic levels and that any 5V peripherals on shared lines have level-shifters, since the LF part's VIH is VDD-dependent.
For the enhanced PWM outputs (PWM1-PWM6 on RC1/RC2/RC5 plus RE0-RE2) driving a 3-phase inverter, keep the PWM traces short and matched in length within 5 mm to avoid timing skew between high-side and low-side FETs. The Motion Feedback Module (MFM) Hall-sensor inputs are highly noise-sensitive; place 1 nF ceramic caps on each Hall input and route them away from the PWM switching traces. The datasheet's typical application schematic shows an RC filter on the MFM input - do not omit it in production designs.
Compliance Information
RoHS and lead-free compliance per Microchip product page; not AEC-Q100 qualified - choose PIC18F2331T-I/ML Q1-grade for automotive. Halogen-free status not explicitly listed in verified data.
