PIC18LF2539-I/SO - 8-Bit MCU, 24KB Flash, 40MHz, 28-SOIC
MPN: PIC18LF2539-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.97 | $5.97 |
| 10 | $5.42 | $54.20 |
| 100 | $4.75 | $475.00 |
| 500 | $4.18 | $2,090.00 |
| 1,000 | $3.65 | $3,650.00 |
PIC18LF2539-I/SO Overview
The PIC18 is an 8-bit modified Harvard RISC microcontroller family — a category of MCU that executes instructions in a single clock cycle (or four clock cycles for branches/table reads), features separate program and data buses for simultaneous instruction fetch plus operand access, and includes a hardware multiplier for fast arithmetic. Within the broader taxonomy: microcontroller -> 8-bit MCU -> PIC18 family -> PIC18F/LF25xx motor-control sub-family -> power-management and motion-control applications. The LF family targets low-power and battery-friendly designs where 5 V system rails are common.
Key features of the PIC18LF2539-I/SO include 24KB of self-programmable Flash memory, 256 bytes of EEPROM, an integrated 10-bit ADC, Capture/Compare/PWM (CCP) and Enhanced CCP modules for motor control, a USART, MSSP (SPI/I2C), and a 34-channel I/O structure with individual direction control. The 40 MHz clock yields up to 10 MIPS instruction throughput, suitable for closed-loop motor control loops in real time. The integrated motor-control kernel provides dedicated PWM, quadrature encoder interface, and Power Factor Correction (PFC) primitives specifically tuned for single-phase induction motors.
The 28-SOIC wide-body (0.295 in / 7.50 mm) package is pin-compatible with the PIC18F2539-I/SO (5 V F-variant) and accepts standard surface-mount reflow profiles. Internal oscillator options reduce BOM cost by eliminating an external crystal in non-precision applications, and the Flash memory supports in-circuit serial programming (ICSP) for field updates. An integrated Power-On Reset (POR) and Brown-Out Reset (BOR) simplify power-rail sequencing.
Typical applications include single-phase induction motor drives (washing machines, fans, pumps, small kitchen appliances), industrial control panels, white-goods inverters, sensor signal conditioning with on-chip ADC, and consumer motor-driven products. The combination of 40 MHz throughput and a dedicated motor-control kernel makes this MCU particularly well suited to field-oriented control (FOC) for single-phase BLDC/induction motors where deterministic interrupt latency is critical.
A common design consideration: choosing the LF (4.2 V–5.5 V) variant versus the F (4.2 V–5.5 V in F2; 2.0 V–5.5 V in K-series) variant depends on whether your system runs from a regulated 5 V rail or from a wider input range. Designers should verify the brown-out voltage threshold and ADC reference topology in the manufacturer datasheet when migrating between sub-families. Note that the SOIC package dissipates less power than the SPDIP package — verify thermal rise during sustained high-I/O switching.
This page synthesises distributor pricing from DigiKey and Octopart, Microchip cross-references, and practical design notes not consolidated in any single source, giving engineers a single point of decision.
Drop-in alternatives for PIC18LF2539-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 PIC18LF2539-I/SO (same form factor and footprint) — differing in ADC, I/O Pins, Core Architecture, Package, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2539-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2539T-I/SO
✅ Drop-In✓ In Stock
$3.49 / Unit
View Datasheet →PIC18LF2539-I/SP
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC18LF252-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.65 / Unit
View Datasheet →PIC18LF2455-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.05 / Unit
View Datasheet →PIC18LF2539-I/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit modified Harvard RISC) |
| Program Memory | 24 KB Flash |
| RAM | 1408 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Frequency | 40 MHz (10 MIPS) |
| Supply Voltage Range | 4.2 V to 5.5 V |
| I/O Pins | 34 (in 28-pin package, multiplexed) |
| ADC | 10-bit |
| Package | 28-SOIC (0.295 in / 7.50 mm wide) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| ROM Type | Flash (self-programmable) |
| Peripherals | CCP/ECCP, USART, MSSP (SPI/I2C), motor-control kernel |
| MSL Level | 1 (per JEDEC J-STD-020, no dry-pack required) |
| RoHS Status | Compliant (lead-free) |
PIC18LF2539-I/SO Pin Configuration
| Pin 1 | MCLR/Vpp — Master Clear (reset, active low) / ICSP programming voltage input |
| Pin 2 | AN0/C12IN0- — Analog input 0 / comparator negative input |
| Pin 3 | AN1/C12IN1- — Analog input 1 / comparator negative input |
| Pin 4 | AN2/C12IN2-/CVref — Analog input 2 / comparator input / CVref output |
| Pin 5 | AN3/C12IN3+ — Analog input 3 / comparator positive input |
| Pin 6 | AN4/T0CKI — Analog input 4 / Timer0 clock input |
| Pin 7 | AN5/SS — Analog input 5 / SPI slave select |
| Pin 8 | Vss — Ground reference |
| Pin 9 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 10 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| Pin 11 | RC0/T1CKI — Digital I/O / Timer1 clock input |
| Pin 12 | RC1/CCP2 — Digital I/O / Capture-Compare-PWM 2 output |
| Pin 13 | RC2/ECCP1/P1A — Digital I/O / Enhanced CCP1 output / PWM 1A |
| Pin 14 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| 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 / USART async transmit / clock |
| Pin 18 | RC7/RX/DT — Digital I/O / USART async receive / data |
| Pin 19 | Vss — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 21 | RB0/INT — Digital I/O / external interrupt |
| Pin 22 | RB1 — Digital I/O |
| Pin 23 | RB2 — Digital I/O |
| Pin 24 | RB3/PGM — Digital I/O / ICSP LVP enable |
| Pin 25 | RB4 — Digital I/O |
| Pin 26 | RB5/PGM — Digital I/O / ICSP LVP enable |
| Pin 27 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 28 | RB7/PGD — Digital I/O / ICSP data |
Typical Applications
PIC18LF2539-I/SO is suitable for 6 applications: Single-Phase Induction Motor Drive, Industrial Fan and Pump Control, White-Goods Inverter Boards, Sensor Signal Conditioning Hub, Consumer Motor-Driven Products, HVAC Blower Control.
Single-Phase Induction Motor Drive
The PIC18LF2539-I/SO is purpose-built by Microchip for single-phase induction motor control in white goods. At 40 MHz / 10 MIPS the core sustains deterministic FOC and PFC loops inside microsecond budgets, while the integrated motor-control kernel offloads PWM generation, quadrature encoder capture, and frequency-to-voltage conversion from software. With 24KB Flash and 1408B RAM, the firmware can host lookup tables, PI controllers, and IEC 60730 class-B safety routines in one chip. The 28-SOIC footprint mates cleanly with TC427 gate drivers and ACPL-P314 opto-isolated IGBT drivers for 200 W to 1 kW washing-machine, range-hood, or pump inverters.
Recommended
Industrial Fan and Pump Control
The PIC18LF2539-I/SO's PWM, Enhanced CCP and 10-bit ADC make it ideal for variable-speed industrial fans and pumps. Real-time closed-loop RPM control via quadrature encoder interrupts runs at 40 MHz with sub-microsecond jitter; on-chip Flash supports in-circuit firmware updates for field service. Industrial -40 °C to +85 °C temperature range matches HVAC, refrigeration, and fluid-handling applications. The 28-SOIC footprint drops onto legacy PIC16 designs with minor firmware rework, while keeping the 4.2-5.5 V supply requirement compatible with regulated 5 V industrial bus rails.
Recommended
White-Goods Inverter Boards
Washing machines, dishwashers, and refrigerator inverter boards rely on the PIC18LF2539-I/SO to combine motor control and user-interface tasks on one MCU. The 24KB Flash / 1408B RAM footprint is sufficient for IEC 60730 class B safety diagnostics, sensorless vector control, and keypad scan logic without external EEPROM. The 10 MIPS core handles triac zero-crossing, BLDC commutation, and temperature monitoring in real time, while the integrated 10-bit ADC simplifies current-sense and tachometer feedback. Lead-free 28-SOIC packaging survives SMT reflow profiles across contract manufacturers.
Recommended
Sensor Signal Conditioning Hub
Use the PIC18LF2539-I/SO as a sensor-interface hub in industrial control panels. The 10-bit ADC multiplexes across multiple 4-20 mA current loops or thermistor bridges, while the USART streams processed data to a parent PLC or HMI. Internal Flash stores calibration constants, sensor linearisation tables, and device identity; 256B EEPROM saves non-volatile settings across power cycles. The 28-SOIC footprint and 4.2-5.5 V supply mate cleanly with industrial 24 V rails after an external DC-DC buck such as the MCP16311 or MCP1700 LDO.
Recommended
Consumer Motor-Driven Products
Hair dryers, blenders, robotic vacuums, and small kitchen appliances benefit from the PIC18LF2539-I/SO combining low cost and motor-control integration. The 28-SOIC footprint supports high-density PCB layouts in space-constrained enclosures, while 4.2-5.5 V operation mates with single-cell Li-ion plus boost-converter rails. The motor-control kernel drives brushed, brushless DC, and single-phase induction motors with hardware-accelerated PWM, simplifying firmware development and shortening time to market. On-chip Flash and EEPROM enable field updates and stored presets (e.g. blender speeds, vacuum modes).
Recommended
HVAC Blower Control
HVAC blower controllers use the PIC18LF2539-I/SO for variable-speed drives that improve comfort and reduce energy cost. The motor-control kernel handles sinusoidal commutation and torque ripple smoothing, while the on-chip 10-bit ADC samples motor phase currents via shunt resistors. Industrial -40 °C to +85 °C operation tolerates duct-plenum ambient temperatures, and the integrated Power-On Reset simplifies line-voltage brown-out detection. The 28-SOIC footprint is footprint-compatible with earlier PIC18F/LF2431 designs common in legacy HVAC boards, easing service replacements.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF2539-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2539-I/SO | PIC18LF2539T-I/SO | PIC18LF2539-I/SP | PIC18LF252-I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (7.50 mm wide) | 28-SOIC - same | 28-SOIC - same | 28-SPDIP - different PCB footprint | 28-SOIC - same |
| Core Architecture | PIC18 (8-bit Harvard RISC) | PIC18 (8-bit) - same | PIC18 (8-bit) - same | PIC18 (8-bit) - same | PIC18 (8-bit) - same |
| Program Memory | 24 KB Flash | 24 KB Flash | 24 KB Flash | 24 KB Flash | 32 KB Flash (+33%) |
| RAM | 1408 bytes | 1408 bytes | 1408 bytes | 1408 bytes | 1536 bytes (+9%) |
| Maximum Clock | 40 MHz (10 MIPS) | 40 MHz - same | 40 MHz - same | 40 MHz - same | 40 MHz - same |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Motor Control Kernel | Yes (single-phase induction motor) | Yes - same kernel | Yes - same kernel | Yes - same kernel | Yes - same family |
| Estimated Unit Price (qty-1) | US $5.97 | Similar ($5-6 range) | Similar ($5-6 range) | Similar ($5-6 range) | Similar ($5-6 range) |
Key Differentiators
- Dedicated single-phase induction motor-control kernel integrated on-chip (vs PIC18F25K22-I/SO)
- Industrial -40 °C to +85 °C operating temperature (vs PIC18LF2539-E/SO (extended commercial))
- Wide-body 28-SOIC (7.50 mm) footprint drop-in compatible with PIC18F/LF legacy designs (vs PIC18F45K22-I/P (40-pin DIP variant))
Design Notes
Estimated: PIC18LF2539-I/SO supply draws typically 2-15 mA active at 40 MHz depending on I/O loading and ADC clock configuration. Always add a 100 nF decoupling capacitor within 5 mm of VDD pin 20 and a bulk 1-10 µF tantalum or ceramic on the supply rail. For brown-out protection, use the configurable BOR voltage setting rather than relying on POR alone, especially in motor-drive environments where DC-bus sag can undercut MCU rail.
Estimated: keep the ICSP pinout (MCLR/Vpp, PGC, PGD) on the board edge with a 6-pin header footprint, even if not populated, to enable field debugging and firmware refresh. Route the crystal traces (OSC1/OSC2) short and symmetric; place a 4.7 kΩ pull-up on MCLR. For 28-SOIC wide-body designs, allocate at least 50 mm² of copper pour on the GND plane adjacent to the package to provide thermal dissipation at high I/O toggle rates.
Route PWM and CCP outputs away from ADC analog inputs; keep analog and digital ground returns separated and joined at a single point near the MCU Vss pin. The 10-bit ADC sampling is sensitive to switching-noise harmonics from the integrated motor-control PWM; place 100 nF + 10 µF RC filters as close as possible to AVdd/Vss pair, and average multiple ADC samples for noisy motor-current measurements. If the motor bridge injects common-mode noise onto the MCU rail, add a π-filter (10 µH + 100 nF + 100 nF) between the bridge return and MCU Vdd.
Three common mistakes: (1) leaving LVP (Low-Voltage Programming) enabled unintentionally by tying PGM high during reset — disable in config bits if not needed; (2) forgetting that the LF variants still need 4.2 V minimum (NOT 3.3 V) — common confusion with the PIC18LFxxK family; (3) exceeding 40 MHz clock at 5.5 V across the industrial -40 °C to +85 °C range — verify timing budget at corners. Always read config bit settings before locking firmware around oscillator source.
Compliance Information
RoHS-compliant per Microchip product page; lead-free (Pb-free) and halogen-free per MSL-1 / JEDEC J-STD-020. No AEC-Q100 automotive qualification — choose a -Q automotive derivative for vehicle designs. Not MRQ-, MMS-, or PSID-qualified; lifecycle status ACTIVE per Verified Web Data 2026-09-28.
