PIC18F2539-E/SP - 8-bit 40MHz 24KB Flash MCU | Microchip
MPN: PIC18F2539-E/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.7 | $4.70 |
| 10 | $4.23 | $42.30 |
| 100 | $3.78 | $378.00 |
| 500 | $3.4 | $1,700.00 |
| 1,000 | $3.05 | $3,050.00 |
PIC18F2539-E/SP Overview
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a single-chip computer that processes data in 8-bit chunks and integrates a CPU, non-volatile program memory (Flash/ROM), volatile data memory (RAM), peripherals, and I/O on one die. The PIC18 family sits within Microchip's broader PIC microcontroller taxonomy: PIC10/12/16/18 (8-bit) -> PIC24/dsPIC33 (16-bit) -> PIC32MX (32-bit MIPS) -> PIC32MM/MZ (32-bit ARM Cortex-M) -> microcontrollers -> embedded computing -> semiconductors. Within the PIC18 hierarchy, the PIC18F2539 belongs to the motor-control sub-family.
Key differentiating features include a sophisticated single-phase induction motor control kernel (Power Control PWM with edge-aligned/center-aligned modes), an ICD (In-Circuit Debugger) interface for hardware debugging, self-programming Flash, and 21 digital I/O lines shared with analog inputs. The PIC18F2539 combines an enhanced 8-bit RISC core with motor-optimized peripherals, eliminating external driver logic for many single-phase BLDC and induction motor applications.
Architecturally, the PIC18F2539 uses Microchip's enhanced Harvard architecture with separate program and data buses, a 32-level hardware stack, and a configurable oscillator block (8 MHz / 4x PLL to 40 MHz). The 10-bit ADC provides 5 channels with auto-acquisition and selectable conversion clock, while the two PWM channels deliver programmable duty, period, and dead-band control tailored for motor drive switching waveforms.
Typical applications include single-phase induction motor control, ceiling fans, washing-machine pump drives, small HVAC blowers, and appliance variable-frequency drives. It also fits industrial relay replacement, sensor signal conditioning with on-chip ADC, and low-cost general-purpose 8-bit embedded control where through-hole SPDIP eases prototyping and field rework.
Design consideration: budget for a 1-3 ms Power-on Reset and oscillator stabilization delay; use the configuration bits to select HS or INTOSC mode and to enable ICD. For motor-drive PCB layouts, keep the H-bridge traces short, place 0.1 uF + 10 uF decoupling at VDD/VSS, and isolate the analog AVSS/AVDD pair.
This page synthesizes drop-in same-package alternatives, parameter-by-parameter comparison, and practical motor-control design notes beyond the data found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F2539-E/SP — 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 PIC18F2539-E/SP (same form factor and footprint) — differing in Package, ADC, I/O Pins, Operating Temperature, PWM Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2539-I/SP
✅ Drop-In✓ In Stock
$3.92 / Unit
View Datasheet →PIC18F2539-E/SO
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC18F2523-I/SP
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC18F2523-E/SP
✅ Drop-In✓ In Stock
$5.85 / Unit
View Datasheet →PIC18F2439-I/SP
✅ Drop-In✓ In Stock
$5.05 / Unit
View Datasheet →PIC18F2539-E/SP Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC enhanced Harvard |
| Program Memory | 24 KB Flash (12K x 16 words) |
| Data RAM | 1408 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 25 (21 digital-only + 4 shared with analog) |
| ADC | 10-bit, 5 channels |
| PWM Channels | 2 (Power Control PWM, edge/center aligned) |
| Package | 28-pin SPDIP (Skinny Plastic DIP) |
| Operating Temperature | -40C to +125C (Extended grade, "-E") |
| Mounting Type | Through-Hole |
| Special Features | Single-phase induction motor control kernel, ICD, self-programming Flash |
PIC18F2539-E/SP Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input / RE3 digital 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/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/AN4 — PORTA bit 4 / analog input 4 |
| Pin 7 | RA5/AN5 — PORTA bit 5 / analog input 5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — External oscillator input / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — External oscillator output / PORTA bit 6 |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 (PWM) |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / UART TX / clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / UART RX / data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (4.2V to 5.5V) |
| Pin 21 | RB0/INT0 — PORTB bit 0 / external interrupt 0 |
| Pin 22 | RB1/INT1 — PORTB bit 1 / external interrupt 1 |
| Pin 23 | RB2/INT2 — PORTB bit 2 / external interrupt 2 |
| Pin 24 | RB3/INT3 — PORTB bit 3 / external interrupt 3 |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICD clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICD data |
Typical Applications
PIC18F2539-E/SP is suitable for 6 applications: Single-Phase Induction Motor Control, Ceiling Fan and Exhaust Fan Variable-Speed Drive, Washing Machine Pump and Drain Motor Controller, Small HVAC Blower and Fan Controller, Appliance Relay Replacement and Smart Switch, Sensor Signal Conditioning with On-Chip ADC.
Single-Phase Induction Motor Control
The PIC18F2539-E/SP is purpose-built for single-phase induction motor control. Its Power Control PWM supports edge-aligned and center-aligned modes with programmable dead-band delay, and the 5-channel 10-bit ADC samples back-EMF or current shunt signals at up to 100 ksps. At 40 MHz CPU speed the control loop executes in under 5 us, allowing zero-crossing detection, soft-start ramp, and overcurrent protection all in firmware. The 24 KB Flash holds state-machine control code plus lookup tables for V/F curves, and the 256 B EEPROM stores trim and run-hour counters without external NVM. Single-phase induction motors typically need only two power switches plus a triac, so this 28-pin SPDIP MCU drives the gate signals directly while keeping BOM minimal.
Recommended
Ceiling Fan and Exhaust Fan Variable-Speed Drive
Ceiling fans and bathroom exhaust fans benefit from the PIC18F2539-E/SP's small footprint, integrated PWM, and ability to drive triac gates directly. The MCU's 40 MHz core and 5 ADC channels handle zero-crossing detection on the AC mains, IR remote demodulation, and temperature-feedback control for variable-speed operation. At 4.2-5.5V supply, the MCU can be powered from a capacitive-dropper or small switching supply derived from the AC line. The 24 KB Flash supports lookup-table-based sine modulation, while the 1408 B RAM buffers instantaneous duty-cycle adjustments without flicker. Compared with a dedicated fan-control ASIC, this approach gives designers full flexibility in adding humidity-sensor input, sleep modes, and remote-control features.
Recommended
Washing Machine Pump and Drain Motor Controller
Washing-machine drain pumps and circulation pumps are small single-phase AC induction motors that need MCU-based control to add soft-start, dry-run protection, and load sensing. The PIC18F2539-E/SP integrates 5 ADC channels for sensing motor current, line voltage, and water level, and its 2 PWM channels can modulate triac firing angle for soft-start ramps that reduce water-hammer and stress on impellers. The 24 KB Flash fits IEC 60730 class B safety firmware (self-test routines) plus the user-interface handling, while 1408 B RAM stores trip counters and diagnostic logs. The 28-pin SPDIP package is easy to hand-prototype during appliance development, and the Extended -40C to +125C temperature grade handles the hot under-cabinet environment.
Recommended
Small HVAC Blower and Fan Controller
Small HVAC blowers in residential air-handlers, furnace heat exchangers, and bathroom fans need silent speed control over a wide range. The PIC18F2539-E/SP's 10-bit ADC delivers 1024-step resolution, enabling fine-grained speed profiling without audible stepping. Its two PWM channels drive the triac gate directly with optocoupler isolation, and the 40 MHz core implements anti-windup PI loops in firmware. The Extended -40C to +125C grade supports under-hood mounting, while the 256 B EEPROM retains the last-set fan speed across power cycles without external non-volatile memory. The 28-pin SPDIP package eases field serviceability - technicians can swap the MCU without specialized tools.
Recommended
Appliance Relay Replacement and Smart Switch
Mechanical relays in white goods and appliance controls can be replaced by solid-state switching driven by the PIC18F2539-E/SP. Its 25 I/O pins handle multiple zero-crossing detectors, button inputs, and triac/MOSFET gate outputs. The 24 KB Flash supports BLE/wireless stack bridging or simple keypad/user-interface logic, and the 5-channel ADC reads current and temperature for fault detection. Compared with discrete relay drivers, the MCU enables soft-switching (reducing EMI), status LED feedback, and overcurrent shutdown. The 256 B EEPROM stores user settings (timer, brightness) across power cycles.
Recommended
Sensor Signal Conditioning with On-Chip ADC
The PIC18F2539-E/SP serves as a low-cost sensor hub where its 5-channel 10-bit ADC digitizes multiple analog sensors (temperature, light, pressure, humidity) and presents processed data over UART/SPI to a host controller. The 40 MHz core runs digital filters and averaging in firmware, while 1408 B RAM buffers samples before transmission. The 24 KB Flash fits sensor-linearization lookup tables, and 256 B EEPROM stores calibration coefficients. The 28-pin SPDIP is easy to breadboard, and the Extended temperature grade supports industrial environments. This is a cost-effective 8-bit alternative to dedicated signal-chain ICs when flexibility matters more than 12-16 bit ADC resolution.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2539-E/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2539-I/SP | PIC18F2523-I/SP | PIC18F2523-E/SP | PIC18F2439-I/SP |
|---|---|---|---|---|---|
| Package | 28-pin SPDIP | 28-pin SPDIP - same | 28-pin SPDIP - same | 28-pin SPDIP - same | 28-pin SPDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 24 KB Flash | 24 KB Flash (same) | 32 KB Flash (+33%) | 32 KB Flash (+33%) | 12 KB Flash (-50%) |
| RAM | 1408 B | 1408 B (same) | 1536 B (+9%) | 1536 B (+9%) | 768 B (-45%) |
| EEPROM | 256 B | 256 B (same) | 256 B (same) | 256 B (same) | 256 B (same) |
| Max CPU Speed | 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 (same) | 4.2 V to 5.5 V (same) | 4.2 V to 5.5 V (same) | 4.2 V to 5.5 V (same) |
| Temperature Grade | Extended -40C to +125C | Industrial -40C to +85C | Industrial -40C to +85C | Extended -40C to +125C | Industrial -40C to +85C |
| Motor-Control Kernel | Yes (single-phase induction) | Yes (same) | Yes (same) | Yes (same) | Yes (same) |
| ADC Channels | 5 x 10-bit | 5 x 10-bit (same) | 5 x 10-bit (same) | 5 x 10-bit (same) | 5 x 10-bit (same) |
Key Differentiators
- Dedicated single-phase induction motor-control kernel on-chip (vs PIC18F2439-I/SP)
- Extended -40C to +125C temperature grade standard (vs PIC18F2539-I/SP)
- More RAM than PIC18F2439 for filter/state buffers (vs PIC18F2439-I/SP)
- Smaller code footprint needed vs larger PIC18F2523 (vs PIC18F2523-I/SP)
Design Notes
Power the PIC18F2539-E/SP from a regulated 5V rail with a ferrite bead in series and a 10 uF tantalum plus 0.1 uF ceramic decoupling pair placed within 5 mm of VDD (pin 20) and VSS (pins 8 and 19). For motor-control boards sharing the 5V rail with the H-bridge, add a TVS diode across VDD/VSS to clamp inductive transients. The MCU's AVDD/VSS pair (if used) should be tied to the same supply with their own 0.1 uF + 10 uF capacitors.
The PIC18F2539-E/SP dissipates negligible power (typical 25 mW at 40 MHz and 5V), so no heatsink is required. However, in enclosed motor-drive enclosures exceeding 70C ambient, derate to industrial-grade parts (PIC18F2539-I/SP) or upgrade to the Extended -40C to +125C grade which is already this part. Ensure free airflow around the SPDIP package and avoid placing large thermal masses directly above the MCU.
Keep the H-bridge switching traces short and wide (>= 2 mm) to minimize ringing. Route the MCU's PWM outputs (CCP1/CCP2, RC2/RC1) directly to the gate-driver inputs with a ground-guard trace. Place the AC-line zero-crossing detection optocoupler near the AC side, and bring the opto output to a high-impedance digital input on the MCU (e.g., RB0/INT0) to avoid ground loops.
Common pitfalls with the PIC18F2539-E/SP include: (1) failing to set the configuration bits for HS oscillator mode when using an external crystal above 4 MHz; (2) forgetting to enable the ICD pins (RB6/RB7) as PGC/PGD in configuration - these are shared with PORTB and can cause debugging failures if not configured; (3) leaving the watchdog timer enabled in production firmware, causing unexpected resets; (4) driving AC-line signals with insufficient creepage/clearance distance in the PCB layout, which fails UL/IEC safety tests.
For back-EMF sensing through the 10-bit ADC, place a 100 ohm + 1 nF RC filter on each analog input to suppress PWM switching noise (typically 20-100 kHz). Use the AVSS/AVDD pin pair (when present) for analog reference, and connect VREF+ to a low-noise 5V reference rather than VDD to achieve full 10-bit ADC accuracy. Acquire ADC samples synchronized to PWM center-aligned mode (when ADC is triggered by PWM interrupt) to avoid sampling during switching transitions.
Compliance Information
Lead-free and RoHS-compliant per Microchip product page; halogen-free status not explicitly confirmed in retrieved data. AEC-Q100 not applicable - this part targets appliance/industrial motor control, not automotive.
