PIC18F25K40-E/SO - 8-Bit MCU, 32KB Flash, 28-Pin SOIC | Microchip
MPN: PIC18F25K40-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.2 | $22.00 |
| 100 | $1.85 | $185.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.32 | $1,320.00 |
PIC18F25K40-E/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, memory (Flash/ROM, RAM, EEPROM), and integrated peripherals on a single silicon die. The PIC18 architecture uses a C-compiler-optimized RISC instruction set with 16-bit instructions, occupying a hierarchical position of MCU -> 8-bit MCU -> RISC MCU -> embedded controller -> semiconductor. The PIC18F25K40 belongs to the PIC18F K40 sub-family, optimized for XLP (eXtreme Low Power) operation while retaining 5V tolerance for mixed-signal environments.
Key features include Core Independent Peripherals such as the Complementary Waveform Generator (CWG), Windowed Watchdog Timer (WWDT), CRC/SCAN memory integrity checking, a 10-bit ADC with computation, a 5-bit DAC, and configurable logic cells. The device operates from 3.0V to 5.5V supply and supports nanoWatt XLP sleep currents below 50 nA in deep sleep, making it suitable for always-on battery applications. The integrated peripheral set reduces external component count.
Architecturally, the PIC18F25K40 uses a Harvard-style bus with separate instruction and data paths, enabling single-cycle execution for most instructions except branches. The 64 MHz internal oscillator and 4x PLL deliver 16 MIPS throughput, while the 10-bit ADC with acquisition timer and threshold compare can trigger peripherals autonomously without CPU wake-up, preserving energy.
Typical applications include industrial sensor conditioning nodes, low-power IoT endpoints, appliance control panels, automotive body electronics, LED lighting controllers, and consumer white goods. The combination of XLP nanoWatt technology, ample memory, and core-independent peripherals addresses both battery-powered and line-powered designs.
When designing with this part, choose the SOIC-28 footprint when through-hole assembly is not required and PCB height is constrained. For AEC-Q100 automotive qualification, consider the PIC18F25K40-E/SO automotive variant. Plan for ICSP programming header access on the PCB.
This page synthesizes distributor pricing, drop-in alternatives, and engineering design notes for engineers evaluating the PIC18F25K40-E/SO for new designs or as a replacement part.
Drop-in alternatives for PIC18F25K40-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 PIC18F25K40-E/SO (same form factor and footprint) — differing in ADC, Program Memory (Flash), Package, DAC, Supply Voltage (VDD).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K40T-I/SO
✅ Drop-In✓ In Stock
$1.6 / Unit
View Datasheet →PIC18F24K40-E/SO
✅ Drop-In✓ In Stock
$1.2 / Unit
View Datasheet →PIC18F25K40-E/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.89 / Unit
View Datasheet →PIC18F25K22-I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F25K20-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.55 / Unit
View Datasheet →PIC18F25K40-E/SO Maximum Ratings & Electrical Characteristics
| CPU Core | PIC18 (8-bit RISC) |
| Program Memory (Flash) | 32 KB |
| Data SRAM | 2 KB (2048 bytes) |
| Data EEPROM | 256 bytes |
| Maximum Clock Frequency | 64 MHz |
| CPU Speed (MIPS) | 16 MIPS |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +125 C (E = Extended) |
| ADC | 10-bit ADC2 (with computation) |
| DAC | 5-bit DAC |
| Package Type | SOIC-28 (SO, 300 mil wide body) |
| Mounting Type | Surface Mount |
| Communication Interfaces | UART, I2C, SPI, EUSART |
| Core Independent Peripherals | CWG, WWDT, CRC/SCAN, CLC |
| Low-Power Technology | nanoWatt XLP |
| RoHS Status | Compliant |
| MSL Level | 1 |
PIC18F25K40-E/SO Pin Configuration
| Pin 1 | RA0/ANA0/C1IN0-/C2IN0-/C3IN0-/C4IN0-/C5IN0-/C6IN0-/C7IN0-/C8IN0-/U1CTSR — Bidirectional I/O / analog input / comparator input / UART1 clear-to-send |
| Pin 2 | RA1/ANA1/C1IN1-/C2IN1-/C3IN1-/C4IN1-/C5IN1-/C6IN1-/C7IN1-/C8IN1-/U1RXR — Bidirectional I/O / analog input / comparator input / UART1 RX |
| Pin 3 | RA2/ANA2/C1IN0+/C2IN0+/C3IN0+/C4IN0+/C5IN0+/C6IN0+/C7IN0+/C8IN0+/VREF-/ZCD — Bidirectional I/O / analog input / comparator positive / VREF- / zero-cross detect |
| Pin 4 | RA3/ANA3/C1IN1+/C2IN1+/C3IN1+/C4IN1+/C5IN1+/C6IN1+/C7IN1+/C8IN1+/VREF+ — Bidirectional I/O / analog input / comparator positive / VREF+ |
| Pin 5 | RA4/ANA4/C1OUT/SRCLK/T0CKI — Bidirectional I/O / analog input / comparator output / SR latch clock / Timer0 clock |
| Pin 6 | RA5/ANA5/MCLR — Bidirectional I/O / analog input / Master Clear (reset) input |
| Pin 7 | RA6/ANA6/OSC2/CLKOUT — Bidirectional I/O / analog input / oscillator output / clock output |
| Pin 8 | RA7/ANA7/OSC1/CLKIN — Bidirectional I/O / analog input / oscillator input / external clock in |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 11 | RB0/ZCD1/ANB0/C2IN1+/CWG1IN1/CCP4/INT0 — Bidirectional I/O / ZCD input / analog input / comparator positive / CWG input / CCP4 / external interrupt 0 |
| Pin 12 | RB1/ANB1/C1IN3-/C2IN3-/C3IN1+/C4IN1+/C5IN1+/C6IN1+/C7IN1+/C8IN1+/SCL1/SCK1 — Bidirectional I/O / analog input / comparator input / I2C1 SCL / SPI1 SCK |
| Pin 13 | RB2/ANB2/C1IN2-/C2IN2-/C3IN2-/C4IN2-/C5IN2-/C6IN2-/C7IN2-/C8IN2-/SDA1/SDI1 — Bidirectional I/O / analog input / comparator input / I2C1 SDA / SPI1 SDI |
| Pin 14 | RB3/ANB3/C1IN0-/C2IN0-/C3IN0-/C4IN0-/C5IN0-/C6IN0-/C7IN0-/C8IN0-/PWM4/SS1 — Bidirectional I/O / analog input / comparator input / PWM4 / SPI1 SS |
| Pin 15 | RB4/ANB4/C2IN1-/C3IN1-/C4IN1-/C5IN1-/C6IN1-/C7IN1-/C8IN1-/PWM5 — Bidirectional I/O / analog input / comparator input / PWM5 |
| Pin 16 | RB5/ANB5/C1IN2+/C2IN2+/C3IN0+/C4IN0+/C5IN0+/C6IN0+/C7IN0+/C8IN0+/PWM6 — Bidirectional I/O / analog input / comparator positive / PWM6 |
| Pin 17 | RB6/ANB6/ICSPCLK — Bidirectional I/O / analog input / ICSP clock |
| Pin 18 | RB7/ANB7/ICSPDAT — Bidirectional I/O / analog input / ICSP data |
| Pin 19 | RC0/ANC0/CWG1IN0 — Bidirectional I/O / analog input / CWG input 0 |
| Pin 20 | RC1/ANC1/CWG1FLT — Bidirectional I/O / analog input / CWG fault input |
| Pin 21 | RC2/ANC2/C3IN1-/C4IN1-/C5IN1-/C6IN1-/C7IN1-/C8IN1-/PWM7 — Bidirectional I/O / analog input / comparator input / PWM7 |
| Pin 22 | RC3/ANC3/C1IN3-/C2IN3-/C3IN2-/C4IN2-/C5IN2-/C6IN2-/C7IN2-/C8IN2-/PWM8 — Bidirectional I/O / analog input / comparator input / PWM8 |
| Pin 23 | RC4/ANC4/C3IN3-/C4IN3-/C5IN3-/C6IN3-/C7IN3-/C8IN3-/CCP2 — Bidirectional I/O / analog input / comparator input / CCP2 |
| Pin 24 | RC5/ANC5/C3IN1+/C4IN1+/C5IN1+/C6IN1+/C7IN1+/C8IN1+/CCP1 — Bidirectional I/O / analog input / comparator positive / CCP1 |
| Pin 25 | RC6/ANC6/C3IN2+/C4IN2+/C5IN2+/C6IN2+/C7IN2+/C8IN2+/CCP3/TX1/CK1 — Bidirectional I/O / analog input / comparator positive / CCP3 / UART1 TX |
| Pin 26 | RC7/ANC7/C3IN0+/C4IN0+/C5IN0+/C6IN0+/C7IN0+/C8IN0+/RX1/DT1 — Bidirectional I/O / analog input / comparator positive / UART1 RX |
| Pin 27 | VSS — Ground reference |
| Pin 28 | VDD — Positive supply voltage (3.0V to 5.5V) |
Typical Applications
PIC18F25K40-E/SO is suitable for 7 applications: Industrial Sensor Conditioning Nodes, Low-Power IoT Endpoints, Appliance Control Panels, LED Lighting Controllers, Automotive Body Electronics, Consumer White Goods, Portable Medical Monitoring Devices.
Industrial Sensor Conditioning Nodes
The PIC18F25K40-E/SO suits industrial 4-20 mA sensor conditioning nodes where its 10-bit ADC2 with computation and 5-bit DAC enable local signal processing without external components. With 32 KB Flash and 2 KB SRAM, the MCU can run Modbus RTU stacks, sensor linearization, and self-calibration routines. The 3.0V-5.5V supply range integrates directly into 24V-bus-derived 5V rails. nanoWatt XLP sleep currents below 50 nA extend battery life in remote wireless sensor transmitters deployed in field instrumentation.
Recommended
Low-Power IoT Endpoints
Battery-powered IoT endpoints benefit from the PIC18F25K40-E/SO's nanoWatt XLP technology, with deep-sleep currents below 50 nA enabling multi-year coin-cell operation. The integrated EUSART supports direct interfacing with LoRa, Sub-GHz, and Bluetooth Low Energy modules. The 10-bit ADC2 with hardware averaging and threshold compare can wake the CPU only when sensor values exceed programmed limits, drastically reducing average power consumption. The 256-byte EEPROM stores configuration and network credentials without battery backup.
Recommended
Appliance Control Panels
The PIC18F25K40-E/SO drives washing machine, dishwasher, and oven user-interface panels where its 28-pin SOIC footprint provides ample I/O for keypad scanning, 7-segment or LCD display driving, and relay control. The Complementary Waveform Generator (CWG) simplifies inverter-style motor control and zero-cross TRIAC triggering without CPU load. With 32 KB Flash and 2 KB SRAM, the device runs state-machine-based UI firmware, fault detection, and serial diagnostics on a single 5V supply without auxiliary logic.
Recommended
LED Lighting Controllers
The PIC18F25K40-E/SO is well-suited for digital-addressable LED lighting controllers (WS2812B, APA102) where its DMA-free CCP and CWG peripherals generate precise timing waveforms. The 10-bit ADC reads ambient light sensors for daylight harvesting, while the 5-bit DAC provides smooth dimming curves via PWM-filtered analog output. The 64 MHz core runs WS2812B bit-banging protocols at 800 kbps while servicing DMX512 or DALI input parsers, all within the 32 KB Flash envelope.
Recommended
Automotive Body Electronics
Inside-cabin automotive body modules such as seat controllers, mirror adjusters, and HVAC blend-door actuators use the PIC18F25K40-E/SO for its 5V tolerance and -40 C to +125 C extended temperature range. The PIC18F K40 family is well-known for automotive applications, supporting LIN bus via the EUSART and direct MOSFET half-bridge driving through the CWG. The CRC/SCAN peripheral detects Flash corruption in safety-relevant functions, and the WWDT provides ASIL-A-grade system supervision.
Recommended
Consumer White Goods
Refrigerators, microwave ovens, and coffee machines deploy the PIC18F25K40-E/SO as the main user-interface controller, taking advantage of its 5V tolerance to interface directly with triac-driving optocouplers and 7-segment LED displays. The 32 KB Flash stores multilingual UI strings, brewing profiles, and fault logs in the 256-byte EEPROM. The Core Independent Peripherals run capacitive touch sensing via the ADC2 with computation and hardware CVD, eliminating dedicated touch ICs in mid-range appliance designs.
Recommended
Portable Medical Monitoring Devices
Battery-powered pulse oximeters, glucose meters, and portable ECG monitors leverage the PIC18F25K40-E/SO's nanoWatt XLP sleep modes and 10-bit ADC2 with computation to achieve weeks-long battery life. The DMA-free CCP modules generate precision timing for SpO2 LED drivers, while the CWG produces isolated transformer drive waveforms for the high-voltage stimulation circuits. Hardware CRC/SCAN validates Flash integrity for medical device firmware reliability, and the 256-byte EEPROM stores patient calibration data securely.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K40-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K40-I/SO | PIC18F25K40T-I/SO | PIC18F24K40-E/SO | PIC18F25K22-I/SO |
|---|---|---|---|---|---|
| Package | SOIC-28 | SOIC-28 - same | SOIC-28 - same | SOIC-28 - same | SOIC-28 - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| CPU Core | PIC18 (8-bit RISC) | PIC18 (8-bit RISC) | PIC18 (8-bit RISC) | PIC18 (8-bit RISC) | PIC18 (8-bit RISC) |
| Flash Memory | 32 KB | 32 KB | 32 KB | 16 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 1 KB | 1.5 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Max Clock Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 2.3V to 5.5V |
| Temperature Range | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +125C (E) | -40C to +85C (I) |
| Core Independent Peripherals | CWG, WWDT, CRC/SCAN, CLC | CWG, WWDT, CRC/SCAN, CLC | CWG, WWDT, CRC/SCAN, CLC | CWG, WWDT, CRC/SCAN, CLC | No CLC, older ECCP |
| Unit Price (1000+ qty) | $1.32 | $1.30 | $1.32 | $1.25 | $1.28 |
Key Differentiators
- Extended -40C to +125C temperature grade with same silicon die as industrial -I variant (vs PIC18F25K40-I/SO)
- 16 KB less Flash than K40 but pin-compatible K40 family member (vs PIC18F24K40-E/SO)
- Newer Core Independent Peripherals (CLC, CWG, CRC/SCAN) versus older K22 family (vs PIC18F25K22-I/SO)
- Wider 3.0V-5.5V supply range with 5V tolerance on I/O (vs PIC18F25K22-I/SO)
Design Notes
The PIC18F25K40-E/SO supports nanoWatt XLP sleep modes with currents below 50 nA in deep sleep with RTCC enabled. For battery-powered designs, place a 100 nF ceramic decoupling capacitor within 3 mm of each VDD pin (pin 10 and pin 28), and a bulk 10 uF tantalum or ceramic capacitor near the supply input. The internal BOR and POR handle slow-rising supplies gracefully, but a 100 ohm series resistor with 1 uF bypass on MCLR pin 6 prevents in-circuit reset glitches during hot-plug events.
For SOIC-28 layouts, route all 28 signals on a single PCB layer if possible, with a continuous ground plane on the adjacent layer. Keep the ICSP lines (RB6/ICSPCLK pin 17 and RB7/ICSPDAT pin 18) accessible via a 2x3 0.1-inch header for production programming and debugging. Add test vias on the MCLR line (pin 6) for in-circuit reset. Estimated: SOIC-28 land pattern per IPC-7351 with 1.27 mm pitch requires approximately 10.3 x 7.5 mm pad area including thermal relief.
When using the 10-bit ADC2 with computation, place the analog reference capacitor (0.1 uF) directly on the VREF+ pin (RA3, pin 4) within 5 mm. Avoid routing digital switching signals (PWM, SPI CLK) parallel to analog inputs (RA0-RA7, RB0-RB5, RC0-RC7) on the same layer. Use a ground guard ring around sensitive analog traces, and keep the ADC acquisition time at minimum 1 us per the K40 datasheet AC characteristics for full 10-bit accuracy.
Do not exceed the absolute maximum ratings of 6.5V on VDD or expose any I/O pin beyond -0.3V to VDD+0.3V; the PIC18F25K40-E/SO is NOT 5V tolerant on digital I/O when VDD is below 5V. Always configure unused I/O pins as outputs with logic low to minimize current consumption, never leave them floating. For ICSP programming, ensure MCLR is pulled to VDD through a 10 kohm resistor during normal operation - if left floating, the device may enter unintended reset states.
Place the 16 MHz external crystal (if used) within 5 mm of pins 7 (OSC1/RA7) and 8 (OSC2/RA6), with a solid ground plane beneath it. Use 22-33 pF load capacitors per crystal manufacturer datasheet, referenced to the local analog ground island. Keep high-frequency signals (SPI, UART) away from the XTAL traces. Estimated: Total oscillator trace length should be kept under 10 mm to minimize parasitic capacitance and EMI susceptibility.
Compliance Information
RoHS compliant per Microchip product page. Industrial /E temperature grade does not require AEC-Q100; for AEC-Q100 qualified automotive variants consult Microchip's automotive-grade PIC18 portfolio.
