PIC18F25K42-E/SS - 8-Bit 64MHz 32KB Flash MCU | Microchip
MPN: PIC18F25K42-E/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.4 | $3.40 |
| 10 | $3.06 | $30.60 |
| 100 | $2.72 | $272.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
PIC18F25K42-E/SS Overview
An 8-bit microcontroller (MCU) is a programmable computing IC that executes instructions 8 bits at a time over an internal data bus. PIC18F devices sit in Microchip's mainstream PIC architecture hierarchy: 8-bit MCU -> PIC18 family -> PIC18FxxK42 sub-family -> low-power XLP platform -> semiconductor. Within an embedded system the MCU provides deterministic real-time control alongside sensors, power and connectivity peripherals, replacing discrete logic while consuming milliwatts of power.
Key features include a 12-bit differential ADC2 supporting automatic averaging and threshold comparison, a hardware DMA controller that moves data between peripherals and memory without CPU intervention, configurable logic cells (CLC) that let designers implement state machines and signal conditioning in silicon, and Functional Safety (FuSa) features such as a dedicated Windowed Watchdog Timer and a CRC scanner. Two UART, two SPI and two I2C interfaces support simultaneous multi-bus connectivity for sensor, display and wireless-module attachment.
The K42 architecture pairs the standard PIC18 RISC core with independent peripherals interconnected through the peripheral pin select (PPS) crossbar, allowing flexible remapping of digital functions to physical pins. The XLP technology delivers typical sleep currents in the nanoamp range, idle currents near 1 uA, and active currents around 200 uA/MIPS - the right combination for always-on battery applications that wake periodically to process data.
Typical applications include low-power IoT sensor nodes, industrial control peripherals, consumer appliances, automotive body and accessory controllers, and USB-to-UART bridging or general digital control. The wide 2.3V-5.5V supply range also lets the part operate directly from a single-cell Li-ion battery or a regulated 3.3V/5V rail.
A key design tip is to use the PPS re-mapping to free up board real estate: nearly every digital peripheral can be routed to multiple physical pins, simplifying PCB routing without changing the silicon. Always configure the watchdog timer for unattended applications to recover from firmware lock-ups.
Drop-in alternatives for PIC18F25K42-E/SS — 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 PIC18F25K42-E/SS (same form factor and footprint) — differing in Package, Core, Operating Temperature, ADC, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K42-I/SS
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F25K42-E/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.18 / Unit
View Datasheet →PIC18F25K42-E/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.05 / Unit
View Datasheet →PIC18F25K42-E/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.79 / Unit
View Datasheet →PIC18F24K42-I/SS
✅ Drop-In✓ In Stock
$1.53 / Unit
View Datasheet →PIC18F25K40-I/SS
✅ Drop-In✓ In Stock
$1.1 / Unit
View Datasheet →PIC18F25K42-E/SS Maximum Ratings & Electrical Characteristics
| Device Family | PIC18FxxK42 (PIC18F24/25K42) |
| Core | PIC18 8-bit RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| RAM | 2 KB |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 64 MHz |
| Operating Voltage Range | 2.3 V to 5.5 V |
| Package | 28-pin SSOP |
| Mounting Type | Surface Mount |
| ADC | 12-bit ADC2 with computation |
| DAC | 5-bit DAC |
| Comparators | Multiple on-chip comparators |
| PWM Modules | Yes (multiple PWM outputs) |
| DMA Channels | Yes (hardware DMA controller) |
| Configurable Logic Cells (CLC) | Yes |
| Vectored Interrupts | Yes |
| Communication Interfaces | 2x UART, 2x SPI, 2x I2C |
| Operating Temperature | -40C to +125C (E suffix) |
| Memory Integrity | Hardware CRC scanner |
| Watchdog | Windowed Watchdog Timer (WWDT) |
| RoHS Status | Compliant |
| Functional Safety | FuSa features included |
PIC18F25K42-E/SS Pin Configuration
| Pin 1 | RA0/AN0 — PORTA Bit 0 / ADC2 channel 0 |
| Pin 2 | RA1/AN1 — PORTA Bit 1 / ADC2 channel 1 |
| Pin 3 | RA2/AN2 — PORTA Bit 2 / ADC2 channel 2 |
| Pin 4 | RA3/AN3 — PORTA Bit 3 / ADC2 channel 3 |
| Pin 5 | RA4/AN4 — PORTA Bit 4 / ADC2 channel 4 |
| Pin 6 | RA5/AN5 — PORTA Bit 5 / ADC2 channel 5 |
| Pin 7 | RA6 — PORTA Bit 6 |
| Pin 8 | RA7 — PORTA Bit 7 |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Positive supply 2.3-5.5V |
| Pin 11 | RB0/AN12 — PORTB Bit 0 / ADC2 channel 12 |
| Pin 12 | RB1/AN10 — PORTB Bit 1 / ADC2 channel 10 |
| Pin 13 | RB2/AN8 — PORTB Bit 2 / ADC2 channel 8 |
| Pin 14 | RB3/AN9 — PORTB Bit 3 / ADC2 channel 9 |
| Pin 15 | RB4 — PORTB Bit 4 |
| Pin 16 | RB5/AN13 — PORTB Bit 5 / ADC2 channel 13 |
| Pin 17 | RB6/ICSPCLK — PORTB Bit 6 / ICSP clock |
| Pin 18 | RB7/ICSPDAT — PORTB Bit 7 / ICSP data |
| Pin 19 | RC0 — PORTC Bit 0 |
| Pin 20 | RC1 — PORTC Bit 1 |
| Pin 21 | RC2 — PORTC Bit 2 |
| Pin 22 | RC3 — PORTC Bit 3 |
| Pin 23 | RC4 — PORTC Bit 4 |
| Pin 24 | RC5 — PORTC Bit 5 |
| Pin 25 | RC6 — PORTC Bit 6 |
| Pin 26 | RC7 — PORTC Bit 7 |
| Pin 27 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 28 | OSC2/CLKO — Crystal oscillator output / clock output |
Typical Applications
PIC18F25K42-E/SS is suitable for 6 applications: Low-Power IoT Sensor Node, Industrial Control Peripheral, Consumer Appliance and Home Device, Automotive Body and Accessory Controller, USB-to-UART/SPI/I2C Bridge, Battery-Powered Measurement Instrument.
Low-Power IoT Sensor Node
The PIC18F25K42-E/SS is purpose-built for battery-powered IoT sensor nodes thanks to its XLP technology delivering sleep currents in the nanoamp range and a 2.3-5.5V supply that directly accepts a single-cell Li-ion rail. With 32 KB of Flash it can hold a LoRaWAN or BLE-beacon stack alongside sensor-fusion code, while the 12-bit ADC2 with computation engine handles thermocouple or load-cell conditioning without external amplifiers. Two UARTs, two SPIs and two I2Cs let the MCU drive a sensor cluster plus a wireless module like the RN2483 simultaneously through the peripheral pin select crossbar. The hardware DMA offloads data movement so the core can stay in sleep between interrupts, extending battery life by years in duty-cycled applications.
Recommended
Industrial Control Peripheral
For industrial PLC expansion I/O and process-control peripherals the PIC18F25K42-E/SS offers 64 MHz of performance, Functional Safety features (Windowed WDT, CRC scanner, Flash ECC), and -40C to +125C operation. The 12-bit ADC2 with hardware oversampling enables accurate 4-20 mA sensor loops, while the configurable logic cells (CLC) can implement hardware interlocks without external CPLD logic. Its 32 KB Flash accommodates Modbus/RTU protocol stacks plus calibration tables stored in 256-byte EEPROM. The two UARTs can simultaneously drive an RS-485 bus and a debug console, while the hardware DMA handles high-speed encoder inputs without loading the CPU.
Recommended
Consumer Appliance and Home Device
In consumer appliances like coffee machines, microwave ovens and smart thermostats the PIC18F25K42-E/SS balances cost, peripherals and power economy. The 5-bit DAC simplifies buzzer or LED brightness control, the comparators enable zero-cross detection for triac control, and the PWM modules drive variable-speed fans and small BLDC motors directly. With 2 KB of RAM it comfortably runs graphical user-interface code driving an SPI LCD, while the EEPROM stores user preferences and last-state values across power cycles. The wide supply range supports 3.3 V and 5 V designs for direct drop-in across product families.
Recommended
Automotive Body and Accessory Controller
Automotive body controllers (lighting, seat control, mirror adjustment) benefit from the PIC18F25K42-E/SS operating across -40C to +125C with functional-safety features. While not AEC-Q100 qualified, the part is widely deployed in non-safety automotive accessories where extreme temperature reliability and predictable reset behavior matter. Its 12-bit ADC2 reads photodiodes for ambient-light sensing, its PWM outputs drive LED current drivers, and its LIN-compatible UART interfaces with body-control transceivers. The hardware CRC scanner checks configuration tables against corruption and the Windowed Watchdog recovers from firmware lock-ups in unattended installations.
Recommended
USB-to-UART/SPI/I2C Bridge
Although the PIC18F25K42-E/SS lacks native USB, it is frequently paired with the Microchip MCP2221A USB-to-UART/I2C/SPI bridge to make a compact PC-to-embedded debug dongle or production programmer. The 64 MHz core plus two UARTs and two I2Cs let the MCU act as an intelligent protocol converter, while the 32 KB Flash stores device profiles that translate vendor-specific protocols to standard USB CDC or HID classes. The wide 2.3-5.5 V supply matches USB VBUS and 3.3 V rails directly. This split-architecture avoids forcing the MCU to learn USB stack overhead and keeps the BOM small.
Recommended
Battery-Powered Measurement Instrument
Handheld measurement instruments benefit from the PIC18F25K42-E/SS thanks to its 64 MHz core speed for fast AD conversions, its 12-bit ADC2 with computation engine for oversampled accuracy, and its XLP nanoWatt sleep between samples. With 32 KB of Flash the device can run a small embedded graphical user interface, calibration algorithms and a data logger for ten thousand readings. The 256-byte EEPROM stores factory calibration coefficients persistent across battery replacement. Two UARTs allow simultaneous Bluetooth-modem link and USB-charging input, while the wide supply range works with 18650 Li-ion and 9 V wall adapters alike.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K42-E/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K42-I/SS | PIC18F25K42-E/SP | PIC18F25K42-E/SO | PIC18F24K42-I/SS | PIC18F25K40-I/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP - same | 28-SPDIP (through-hole) | 28-SOIC (wider body) | 28-SSOP - same | 28-SSOP - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Flash / RAM | 32 KB / 2 KB | 32 KB / 2 KB | 32 KB / 2 KB | 32 KB / 2 KB | 16 KB / 1 KB | 32 KB / 2 KB |
| ADC | 12-bit ADC2 w/ computation | 12-bit ADC2 w/ computation | 12-bit ADC2 w/ computation | 12-bit ADC2 w/ computation | 12-bit ADC2 w/ computation | 10-bit ADC |
| CLC (Configurable Logic Cells) | Yes (K42 new feature) | Yes | Yes | Yes | Yes | No (K40 lacks CLC) |
| Hardware DMA | Yes | Yes | Yes | Yes | Yes | Yes (limited channels) |
| Operating Temperature | -40C to +125C (E grade) | -40C to +85C (I grade) | -40C to +125C (E grade) | -40C to +125C (E grade) | -40C to +85C (I grade) | -40C to +85C (I grade) |
| Functional Safety (WWDT + CRC) | Yes (FuSa features) | Yes | Yes | Yes | Yes | Partial (no dedicated CRC) |
Key Differentiators
- 12-bit ADC2 with computation engine and oversampling (vs PIC18F25K40-I/SS)
- Configurable Logic Cells (CLC) replace external logic gates (vs PIC18F25K40-I/SS)
- Functional Safety (FuSa) feature set included (vs PIC18F25K22-I/SS)
- Hardware DMA controller on integrated K42 core (vs PIC18F24K40T-I/SS)
Design Notes
Estimated: at 64 MHz active and 3.3V the PIC18F25K42-E/SS draws roughly 7-9 mA from the K42 datasheet active current curves; use Sleep mode between events with XLP technology to drop below 1 uA. Always place a 100 nF decoupling capacitor as close as possible to the VDD/VSS pins, plus a 10 uF bulk capacitor at the regulator output. The brown-out-reset voltage is configurable; program it for 2.7 V on 3.3 V rails to maintain safe reset conditions during battery droop.
Route the ICSP clock (RB6/ICSPCLK) and ICSP data (RB7/ICSPDAT) to a 6-pin header so MPLAB ICD 4 or PICKIT can program and debug the device in-circuit. The K42 family supports perimeter scan and trace but is sensitive to long traces - keep ICSP lines under 50 mm and avoid routing alongside high-current switching signals. Place the 32.768 kHz secondary crystal on pins defined in the PPS configuration for RTC work, not on the primary oscillator pins.
Use the Peripheral Pin Select (PPS) crossbar feature to map U(S)ART, SPI and I2C functions to convenient physical pins. PPS re-mapping frees PCB real estate and allows multiple SPI buses on different pins. The configuration bits must be set BEFORE main(); reading residual configuration can cause UART noise on remapped pins at startup. Always lock PPS configuration in production code to prevent accidental re-mapping during firmware update.
A common firmware pitfall is forgetting to clear the ADC2 computation accumulator after each conversion - this rolls the average and produces drifting readings. The DMA controller on the K42 has a fixed start-of-pattern - confirm the source and destination address remain within RAM bounds to avoid hard faults. Last-note: the FVR (Fixed Voltage Reference) must be enabled in software before ADC2 uses it; otherwise the ADC readings will ratchet against VDD and shift with supply variation.
For continuous active operation, calculate worst-case core dissipation: at 64 MHz / 3.3 V / I_active_max, the SSOP-28 thermal resistance θJA is roughly 80 C/W per the package thermal data. A board with 4-layer copper pours around the MCU grounds and decoupling traces keeps junction temperature well within ratings. For high-ambient environments the QFN-28 (/ML) variant offers a lower θJA (~30 C/W) thanks to the thermal pad.
Compliance Information
RoHS and lead-free per Microchip product page. Part is not AEC-Q100 qualified; not recommended for safety-critical automotive applications - use PIC18F25K40-I/SSVAO or similar AEC-Q100 part instead. Functional Safety (FuSa) features are included for IEC 60730-class appliances but do not constitute AEC-Q100 automotive qualification.
