PIC18LF25K42-E/SO - 32KB Flash 8-bit MCU, 28-SOIC | Microchip
MPN: PIC18LF25K42-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.74 | $2.74 |
| 10 | $2.46 | $24.60 |
| 100 | $2.21 | $221.00 |
| 500 | $1.97 | $985.00 |
| 1,000 | $1.76 | $1,760.00 |
PIC18LF25K42-E/SO Overview
An 8-bit microcontroller (MCU) is a programmable single-chip computer built around an 8-bit data path, integrating a CPU, non-volatile program memory (Flash), volatile data memory (RAM), timers, communication peripherals (USART, SPI, I2C), and analog peripherals (ADC, DAC, comparators) on one silicon die. The PIC18 family sits inside a hierarchy of microcontroller -> embedded controller -> semiconductor; PIC18F uses 5 V tolerant CMOS while PIC18LF targets low-voltage battery-powered designs where the supply rail cannot exceed 3.6 V.
Key differentiating features include a 12-bit ADC with up to 24 channels, a 5-bit DAC, on-chip Direct Memory Access (DMA) for CPU-offloaded data movement, vectored interrupts for fast ISR latency, and a rich set of Core Independent Peripherals (CIPs) such as CLC, CWG, NCO and PWM that run without software. These features let a single PIC18LF25K42 replace multiple discrete components in a compact 28-SOIC footprint.
The device's architecture pairs a RISC-like 8-bit core with a 16-bit instruction word and a 31-level hardware stack, while CIPs and the DMA engine offload the CPU. The integrated 64 MHz internal oscillator (+/- 1%) eliminates the external crystal in most designs, reducing BOM cost and PCB area. XLP technology keeps typical sleep currents low, well suited for battery-powered IoT sensor nodes.
Typical applications include low-power IoT sensor nodes, consumer appliance control (white goods, coffee machines, air purifiers), industrial sensor interfaces, USB-CDC and small HMI panels, and battery-driven metering. Designers choose the LF variant whenever the system rail stays at or below 3.3 V; for 5 V rails the PIC18F25K42 (without LF) is recommended.
When designing, ensure that VDD decoupling capacitors (100 nF + 1 uF) are placed within 3 mm of the VDD pin and that the MCLR pull-up is correctly handled in in-circuit serial programming (ICSP). The LF's 3.6 V absolute maximum must be respected; transients above this can permanently damage the part. Use the DMA controller with care when changing channel priorities at runtime.
Drop-in alternatives for PIC18LF25K42-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 PIC18LF25K42-E/SO (same form factor and footprint) — differing in Package, Program Memory (Flash), ADC, Operating Temperature, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K42-E/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.05 / Unit
View Datasheet →PIC18F25K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF25K40-I/SO
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC18LF24K42-I/SO
✅ Drop-In✓ In Stock
$0.96 / Unit
View Datasheet →PIC18F25K22-I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18LF25K42-E/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit) |
| Program Memory (Flash) | 32 KB |
| Data SRAM | 2 KB |
| EEPROM | 256 B |
| Maximum CPU Frequency | 64 MHz |
| Operating Voltage Range | 1.8 V to 3.6 V |
| Number of I/O Pins | 25 |
| ADC Resolution | 12-bit, up to 24 channels |
| DAC | 5-bit x 1 |
| Comparators | Yes |
| DMA Channels | Yes (peripheral-to-memory) |
| Timer Modules | Multiple (CCP, PWM, 16/8-bit) |
| Communication Peripherals | UART, SPI, I2C |
| Package | 28-pin SOIC (SO, 7.5 mil) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (E grade) |
| Data Bus Width | 8 bit |
| Instruction Set Architecture | PIC RISC, 16-bit instruction word |
| XLP (eXtreme Low Power) | Yes |
| On-chip Oscillator | 64 MHz internal |
| RoHS Status | Compliant |
PIC18LF25K42-E/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, internal pull-up enabled |
| Pin 2 | RA0 — Port A bit 0 / AN0 / ICSPDAT |
| Pin 3 | RA1 — Port A bit 1 / AN1 / ICSPCLK |
| Pin 4 | RA2 — Port A bit 2 / AN2 |
| Pin 5 | RA3 — Port A bit 3 / AN3 / VREF+ |
| Pin 6 | RA4 — Port A bit 4 / AN4 |
| Pin 7 | RA5 — Port A bit 5 / AN5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7 — Port A bit 7 / OSC1 |
| Pin 10 | RA6 — Port A bit 6 / OSC2 |
| Pin 11 | RC0 — Port C bit 0 |
| Pin 12 | RC1 — Port C bit 1 |
| Pin 13 | RC2 — Port C bit 2 |
| Pin 14 | RC3 — Port C bit 3 / SCL |
| Pin 15 | RC4 — Port C bit 4 / SDA |
| Pin 16 | RC5 — Port C bit 5 |
| Pin 17 | RC6 — Port C bit 6 / TX |
| Pin 18 | RC7 — Port C bit 7 / RX |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (1.8 V to 3.6 V) |
| Pin 21 | RB0 — Port B bit 0 / INT0 |
| Pin 22 | RB1 — Port B bit 1 / INT1 |
| Pin 23 | RB2 — Port B bit 2 / INT2 |
| Pin 24 | RB3 — Port B bit 3 / INT3 |
| Pin 25 | RB4 — Port B bit 4 |
| Pin 26 | RB5 — Port B bit 5 |
| Pin 27 | RB6 — Port B bit 6 / ICSP programming |
| Pin 28 | RB7 — Port B bit 7 / ICSP programming |
Typical Applications
PIC18LF25K42-E/SO is suitable for 6 applications: Battery-Powered IoT Sensor Node, Consumer White Goods Control, Industrial 4-20 mA Sensor Interface, Small HMI / Control Panel, USB-less Datalogger for Metrology, Brushed DC Motor Control Board.
Battery-Powered IoT Sensor Node
PIC18LF25K42-E/SO suits long-life IoT sensor nodes because its LF supply range (1.8-3.6 V) lets it run directly from a 3 V coin cell or two AA cells, and its XLP low-power modes hit micro-amp-level sleep currents. The integrated 12-bit ADC with up to 24 channels pairs with the DMA engine to sample environmental sensors in the background without waking the CPU on every conversion. Per Microchip datasheet DS40001818D, the on-chip 64 MHz oscillator can be divided down to 32 kHz for sleep, giving 4 MIPS without external components. The 28-SOIC footprint stays compact on coin-cell boards while leaving headroom for a sub-GHz transceiver daughter board.
Recommended
Consumer White Goods Control
In coffee machines, air purifiers, and small kitchen appliances, PIC18LF25K42-E/SO functions as the central controller that reads HMI buttons, drives TRIACs via optoisolators, and regulates a small BLDC or brushed fan motor. Its 5-bit DAC and on-chip comparators let the designer implement closed-loop fan RPM control without external op-amps, and the DMA + CIPs offload pulse-train generation to hardware, freeing the CPU for display handling. Extended -40C to +125C operating range from the -E suffix tolerates under-hood appliance temperatures. The 28-SOIC package is hand-solderable, accelerating prototype spin cycles.
Recommended
Industrial 4-20 mA Sensor Interface
PIC18LF25K42-E/SO can digitize a 4-20 mA loop signal through its 12-bit ADC while the integrated DAC drives the loop excitation current for self-test. The extended -40C to +125C temperature grade (E suffix) keeps the device within spec inside sealed industrial enclosures next to motors and relays. DMA channels let the ADC trigger conversions into RAM without CPU intervention, ensuring deterministic sample timing for IEC 61131-2 compliant control loops. The LF supply range matches 24 V loop-derived 3.3 V rails through a low-dropout regulator, simplifying the power tree compared to 5 V MCUs.
Recommended
Small HMI / Control Panel
PIC18LF25K42-E/SO drives a 2- to 4-inch TFT or character LCD as a small HMI because it has enough MIPS to refresh a 320x240 panel while still scanning a keypad matrix. Its hardware CLC (Configurable Logic Cell) and PWM peripherals generate timing for backlight dimming and buzzer tones without CPU load. SPI runs at up to FOSC/2 (about 32 MHz) so the MCU can talk to a touchscreen controller or external SPI Flash for asset logging. The 28-SOIC package is easy to integrate alongside 5 V-tolerant I/O on industrial panels when paired with the F variant of the same chip.
Recommended
USB-less Datalogger for Metrology
Engineers building portable dataloggers pick PIC18LF25K42-E/SO because the 32 KB Flash and 2 KB SRAM store tens of kilobytes of timestamped ADC readings while the 64 MHz core performs RMS or FFT post-processing. The LF supply range maximizes coin-cell runtime between maintenance cycles, and XLP sleep preserves battery when not actively logging. UART and SPI expose the data to Bluetooth or SD-card modules; the device's 256-byte EEPROM carries calibration constants per Microchip datasheet. The 28-SOIC makes field-replacement straightforward during service operations.
Recommended
Brushed DC Motor Control Board
PIC18LF25K42-E/SO drives a brushed DC motor by combining its 12-bit ADC for current sensing, its PWM module for H-bridge control, and its CWG (Complementary Waveform Generator) for dead-band timing without CPU load. The DMA engine streams ADC samples into RAM for block current averaging, and the integrated 5-bit DAC generates a reference for the analog comparator that protects against shoot-through. The -40C to +125C operation reliably covers fan or pump enclosures. Through-hole SPDIP-28 (E/SP) is recommended for hobbyist builds while SOIC-28 suits SMD mass-production.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF25K42-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K42-E/SO | PIC18F25K40-I/SO | PIC18LF25K40-I/SO | PIC18LF24K42-I/SO | PIC18F25K22-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (SO) | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Operating Voltage | 1.8 V - 3.6 V (LF) | 2.3 V - 5.5 V (F) | 2.3 V - 5.5 V (F) | 1.8 V - 3.6 V (LF) | 1.8 V - 3.6 V (LF) | 1.8 V - 5.5 V |
| Flash Memory | 32 KB | 32 KB | 32 KB | 16 KB | 16 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 1 KB | 1.5 KB |
| Max CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Temperature (suffix) | -40C to +125C (E) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) |
| DMA Controller | Yes | Yes | No | No | Yes | No |
| Approx. 1k-unit Price (USD) | $1.76 | $1.65 | $1.55 | $1.70 | $1.55 | $2.10 |
Key Differentiators
- Lowest-voltage LF (1.8-3.6 V) operation with full K42 feature set (vs PIC18F25K22-I/SO)
- Highest temperature grade in this group (vs PIC18F25K40-I/SO)
- Largest on-chip Flash in 28-SOIC LF parts (vs PIC18LF24K42-I/SO)
Design Notes
Estimated: at the LF supply maximum of 3.6 V and a 16 MIPS workload, the PIC18LF25K42-E/SO core draws on the order of 3-5 mA; sleep currents fall into the sub-10 uA range with XLP peripherals disabled. Decouple VDD with a 100 nF X7R ceramic placed within 3 mm of pin 20, plus a bulk 1 uF ceramic. Avoid long trace inductance on VDD or the part may brown-out during peak current transients.
Place the MCLR pin pull-up (typically 10 kohm to VDD) close to pin 1 and never leave it floating. Route ICSPDAT (RA0) and ICSPCLK (RA1) straight to the programming header with no series resistance so debuggers can drive them. Keep the analog VREF+ traces short and guarded by a digital ground ring to keep ADC noise below 1 LSB. The 28-SOIC land pattern is the standard EIA SO-7.5 mm.
Do not exceed 3.6 V on VDD - the LF die is not 5 V tolerant. For mixed 5 V systems, use the F variant of the same chip. Also watch out for ADC sampling on RC3/RC4 (which double as I2C lines) while I2C is active - the I2C drivers will load the analog input and bias the conversion. Use a free ADC channel on port B (or PA4/PA5) for sensitive measurements.
Compliance Information
RoHS and lead-free per Microchip product page. Not AEC-Q100 qualified - use AEC-Q100 PIC18F variants for automotive.
