PIC18LF25K50-I/SO - 8-Bit 48MHz XLP MCU 32KB Flash | Microchip
MPN: PIC18LF25K50-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.75 | $275.00 |
| 500 | $2.42 | $1,210.00 |
| 1,000 | $2.15 | $2,150.00 |
PIC18LF25K50-I/SO Overview
A PIC (Peripheral Interface Controller) microcontroller is a Harvard-architecture RISC processor family from Microchip Technology that integrates a CPU core, Flash program memory, RAM, EEPROM, and configurable peripherals onto a single die. PIC microcontrollers occupy the same role in 8-bit embedded systems as 32-bit ARM Cortex-M MCUs do for higher-performance applications - they handle system control, sensor I/O, and human-machine interface tasks where cost, simplicity, and low power are critical. PIC18 is the high-performance 16-bit instruction word sub-family with C-optimized architecture, sitting above PIC10/12/16 and below dsPIC and PIC32 in Microchip's lineup.
Key specifications of the PIC18LF25K50-I/SO include 32KB (16K x 16 words) of self-read/write Flash, 2KB RAM, 256 bytes EEPROM, 25 channels of 10-bit ADC, an Enhanced Capture Compare PWM (ECCP) module with up to 4 outputs, an internal 48MHz oscillator with USB-grade accuracy tunable via Active Clock Tuning from the USB host, and a hardware 8x8 multiplier. The integrated Full-Speed USB 2.0 module eliminates the need for an external USB PHY, and the integrated Temperature Indicator aids thermal management. The 28-SOIC package is the most popular through-hole-friendly surface-mount option, supporting hand prototyping and rework.
Typical applications include USB HID peripherals (keyboards, mice, custom input devices), USB-to-UART bridges, low-power sensor nodes, battery-powered data loggers, and consumer USB charging controllers. The wide operating voltage range (1.8V-3.6V) makes the part suitable for single-cell Li-Ion and two-cell alkaline battery packs, where sleep currents below 1uA extend battery life into the year range for periodic-sampling applications.
When designing with this part, ensure the internal 48MHz oscillator is calibrated for USB operation via the Active Clock Tuning feature - the USB specification mandates +/- 0.25% clock accuracy, which the internal oscillator alone cannot guarantee. For multi-rail designs, the LF (low-voltage F) core allows direct connection to coin-cell or single Li-Ion cells without external LDO. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18LF25K50-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 PIC18LF25K50-I/SO (same form factor and footprint) — differing in Package, ADC, Maximum CPU Frequency, Program Memory (Flash), Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF25K50-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF24K50-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K50-I/SO
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →PIC18F45K50-I/PT
✅ Drop-In✓ In Stock
$2.74 / Unit
View Datasheet →PIC18LF25K50-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit, 16-bit instruction word, Harvard) |
| Maximum CPU Frequency | 48 MHz |
| Program Memory (Flash) | 32 KB (16K x 16 words) |
| Data RAM | 2 KB |
| Data EEPROM | 256 bytes |
| Operating Voltage Range | 1.8 V to 3.6 V (LF core) |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| ADC | 10-bit, up to 25 channels |
| USB Module | USB 2.0 Full-Speed (12 Mbps), integrated transceiver |
| PWM Outputs (ECCP) | Up to 4 outputs |
| Hardware Multiplier | 8x8 single-cycle |
| Internal Oscillator | 48 MHz with Active Clock Tuning from USB host |
| Temperature Indicator | Integrated |
| Package | 28-SOIC (7.50 mm / 0.295" width) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Yes (per Microchip product page) |
| XLP Low-Power Technology | Yes (eXtreme Low Power) |
| Self-Read/Write Flash | Yes |
PIC18LF25K50-I/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input; must be pulled high for normal operation |
| Pin 2 | RA0 — PORTA bit 0 / analog input AN0 |
| Pin 3 | RA1 — PORTA bit 1 / analog input AN1 |
| Pin 4 | RA2 — PORTA bit 2 / analog input AN2 |
| Pin 5 | RA3 — PORTA bit 3 / analog input AN3 / VREF+ |
| Pin 6 | RA4 — PORTA bit 4 / analog input AN4 |
| Pin 7 | RA5 — PORTA bit 5 / analog input AN5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7 — PORTA bit 7 / oscillator input |
| Pin 10 | RA6 — PORTA bit 6 / oscillator output |
| Pin 11 | RC0 — PORTC bit 0 |
| Pin 12 | RC1 — PORTC bit 1 |
| Pin 13 | RC2 — PORTC bit 2 |
| Pin 14 | RC3 — PORTC bit 3 |
| Pin 15 | RC4 — PORTC bit 4 / USB D- |
| Pin 16 | RC5 — PORTC bit 5 / USB D+ |
| Pin 17 | RC6 — PORTC bit 6 / TX |
| Pin 18 | RC7 — PORTC bit 7 / RX |
| Pin 19 | VSS — Ground reference (second) |
| Pin 20 | VDD — Positive supply (1.8V to 3.6V) |
| Pin 21 | RB0 — PORTB bit 0 / analog input AN12 |
| Pin 22 | RB1 — PORTB bit 1 / analog input AN10 |
| Pin 23 | RB2 — PORTB bit 2 / analog input AN8 |
| Pin 24 | RB3 — PORTB bit 3 / analog input AN9 |
| Pin 25 | RB4 — PORTB bit 4 / analog input AN11 |
| Pin 26 | RB5 — PORTB bit 5 / analog input AN13 |
| Pin 27 | RB6 — PORTB bit 6 / ICSPCLK |
| Pin 28 | RB7 — PORTB bit 7 / ICSPDAT |
Typical Applications
PIC18LF25K50-I/SO is suitable for 6 applications: USB HID Peripherals (Keyboards, Mice, Custom Input), USB-to-UART Bridge and CDC Virtual COM Port, Low-Power Battery-Powered Sensor Nodes, USB Charging Controllers and Power Bank Interfaces, Consumer Electronics with USB-C and Audio Interfaces, Industrial Data Acquisition Modules.
USB HID Peripherals (Keyboards, Mice, Custom Input)
The PIC18LF25K50-I/SO is purpose-built for USB Human Interface Device (HID) peripherals thanks to its integrated USB 2.0 Full-Speed transceiver and 1.8V-3.6V VDD range. With 32KB Flash and 2KB RAM, the part comfortably holds Microchip's free USB stack (USB Device - HID - CDC), bootloader, and application firmware without external memory. The internal 48MHz oscillator with Active Clock Tuning from the USB host meets the USB 2.0 +/-0.25% clock accuracy requirement, eliminating the cost of an external crystal. Designers benefit from 25 ADC channels for multi-key matrix scanning or analog joystick axes, and the ECCP module provides PWM outputs for LED backlighting or haptic feedback. Typical circuit: VBUS detection on a GPIO, direct D+/D- to the USB connector with ESD protection, and MCLR held high via 10k pull-up.
Recommended
USB-to-UART Bridge and CDC Virtual COM Port
The integrated USB transceiver plus the Enhanced USART module makes the PIC18LF25K50-I/SO ideal for USB-to-UART bridge dongles and CDC-class virtual COM port converters. A typical application pairs this MCU with a USB-B or USB-C receptacle and exposes a serial interface to a host MCU that lacks native USB. The 2KB RAM handles USB ping-pong buffering plus UART FIFOs without dropping packets at 115200 baud, and the 256-byte EEPROM stores user configuration like VID/PID overrides or baud rate defaults. The LF core's 1.8V minimum lets the bridge operate from a 3.3V regulated rail or directly from Li-Ion. Compared to dedicated bridge ICs like FTDI FT232R, this approach is firmware-customizable but requires Microchip's USB stack to be programmed into Flash at production.
Recommended
Low-Power Battery-Powered Sensor Nodes
With XLP (eXtreme Low Power) technology, the PIC18LF25K50-I/SO achieves sleep currents below 1uA while retaining RAM and the ability to wake on interrupt, making it well-suited for battery-powered wireless sensor nodes and data loggers. The integrated 10-bit ADC with up to 25 channels handles multiple analog sensors (temperature, voltage, current) without external muxing. The 1.8V minimum VDD permits direct connection to a single Li-Ion cell or two alkaline cells, eliminating the LDO. The internal Temperature Indicator provides on-die thermal monitoring for compensation or safety shutdown. Energy budget example: at 1Hz wake, measure, transmit (via UART to an attached radio), and return to sleep, the average current can be held below 50uA, giving years of life from a single CR2032 coin cell.
Recommended
USB Charging Controllers and Power Bank Interfaces
The PIC18LF25K50-I/SO serves as the MCU brain for USB charging controllers in power banks and USB hubs, where it monitors battery voltage via ADC, drives status LEDs via PWM, negotiates USB BC 1.2 or proprietary charge protocols via GPIO, and reports state over USB to the host. The integrated USB transceiver eliminates the need for an external bridge chip, and 25 ADC channels support simultaneous voltage and current monitoring on multiple ports. The ECCP module generates PWM for LED brightness control or for driving a buck converter feedback node. The LF variant's 1.8V-3.6V range covers single-cell Li-Ion chemistries directly, while the 28-SOIC package offers compact PCB integration in slim power bank enclosures.
Recommended
Consumer Electronics with USB-C and Audio Interfaces
In consumer audio peripherals such as USB headsets, MIDI controllers, and audio interfaces, the PIC18LF25K50-I/SO provides USB connectivity, HID/CDC buttons and knobs, and PWM for LED ring indicators or motor control. The 48MHz CPU clock handles audio sample rate conversion at common USB audio rates (44.1/48 kHz) without aliasing. The 256-byte EEPROM stores user-preset configurations such as EQ curves or button mappings. The integrated temperature indicator is useful for monitoring USB VBUS die temperature during high-current charging. Compared to dedicated USB audio DSPs, the K50 offers lower BOM cost at the price of more careful firmware design for audio streaming.
Recommended
Industrial Data Acquisition Modules
For industrial 4-20mA loop-powered transmitters, USB-configured sensor modules, and factory-floor data loggers, the PIC18LF25K50-I/SO combines a wide ADC channel count with USB configurability and XLP low power. The 10-bit ADC with 25 channels handles multi-sensor scanning in process control, while the integrated USB transceiver lets technicians plug into a laptop to calibrate or stream logs without an external bridge chip. The industrial -40C to +85C temperature grade ("I" suffix) supports most indoor factory environments; for harsher settings designers step up to the -40C to +125C extended ("E") variant. The 28-SOIC package is also easier to rework than QFP alternatives, simplifying field service.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF25K50-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF25K50-E/SO | PIC18LF24K50-I/SO | PIC18F25K50-I/SO |
|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 16 KB (-50%) | 32 KB |
| RAM | 2 KB | 2 KB | 2 KB | 2 KB |
| Operating Voltage | 1.8V - 3.6V (LF core) | 1.8V - 3.6V (LF core) | 1.8V - 3.6V (LF core) | 1.8V - 5.5V (F core, +1.9V wider) |
| Operating Temperature | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| USB Module | USB 2.0 Full-Speed integrated | USB 2.0 Full-Speed integrated | USB 2.0 Full-Speed integrated | USB 2.0 Full-Speed integrated |
| ADC Channels | 25 channels, 10-bit | 25 channels, 10-bit | 25 channels, 10-bit | 25 channels, 10-bit |
| Lifecycle Status | active | active | active | active |
Key Differentiators
- Lowest VDD minimum (1.8V) for direct Li-Ion battery operation (vs PIC18F25K50-I/SO)
- Industrial -40C to +85C temperature grade vs higher-spec extended option (vs PIC18LF25K50-E/SO)
- 32KB Flash capacity vs the K24 sibling's 16KB (vs PIC18LF24K50-I/SO)
Design Notes
Estimated: At 48MHz, VDD=3.3V, and typical I/O loading, the PIC18LF25K50-I/SO active current is approximately 11-15 mA. Sleep current with WDT disabled and BOR enabled is below 1uA. For USB bus-powered designs, ensure the upstream 3.3V LDO can source at least 100 mA peak during USB enumeration; Microchip's MCP1700, MCP1825, or the TC2117 are common companions. Always enable the BOR (Brown-Out Reset) fuse for production to prevent code corruption during VDD droop.
The internal 48MHz oscillator alone does NOT meet USB 2.0 +/-0.25% accuracy. Per Microchip's datasheet and USB 2.0 specification, the Active Clock Tuning feature (ACT) must be enabled so the MCU calibrates its internal oscillator against the USB host's Start-of-Frame packets. Without ACT, USB enumeration fails intermittently. Additionally, do not omit the 1k-ohm pull-up on D+ (full-speed); connect it to a 3.3V rail via a software-controlled GPIO to support software disconnect/reconnect.
Keep D+ and D- traces matched in length (within 2-3mm) and short (under 50mm total). Route them over a continuous ground plane and avoid the path of switching regulator edges. Place ESD protection diodes (e.g., USBLC6-2SC6) close to the USB connector. Decouple VDD with 100nF ceramic within 5mm of each VDD pin and add a bulk 10uF tantalum or ceramic cap at the regulator output. The ICSP pins RB6/RB7 (pins 27/28) must be brought out to a 5-pin header for in-circuit programming and debugging with MPLAB PICkit 4/5 or ICD 4.
Compliance Information
RoHS and lead-free per Microchip product page. Not AEC-Q100 qualified - the PIC18F25K50 automotive variants exist separately. MSL Level 1, peak reflow 245-260C per IPC/JEDEC J-STD-020.
