PIC18LF25K50T-I/SS - 8-bit USB MCU, 32KB Flash, 48MHz | Microchip
MPN: PIC18LF25K50T-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.41 | $3.41 |
| 10 | $3.07 | $30.70 |
| 100 | $2.46 | $246.00 |
| 500 | $2.1 | $1,050.00 |
| 1,000 | $1.85 | $1,850.00 |
PIC18LF25K50T-I/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and programmable peripherals around a single die. The PIC18 family is Microchip's 8-bit RISC architecture with an enhanced instruction set including hardware 8x8 multiply; within Microchip's MCU taxonomy it sits at: PIC18F/LF -> PIC18 XLP -> 8-bit MCU -> microcontroller -> semiconductor. The 'LF' prefix denotes the low-voltage (F) Flash family operating down to 1.8V, while XLP (eXtreme Low Power) targets nanoWatt sleep currents below 100 nA typical.
Key features include 25-channel 10-bit ADC, two Capture/Compare/PWM (CCP) modules, one Enhanced CCP, two UART, one SPI, one I2C with Master/Slave support, 25 I/O pins, two 8-bit timers plus three 16-bit timers, and an internal 48 MHz oscillator. The integrated USB 2.0 Full-Speed transceiver eliminates the external 1.5 kohm pull-up resistor and clock crystal typical of legacy PIC MCUs.
The PIC18LF25K50 architecture uses a Harvard RISC core with separate program and data buses, a 31-level hardware stack, and self-programming Flash. The Active Clock Tuning peripheral calibrates the internal oscillator against the USB host's SOF packets, achieving +/- 0.25% USB clock accuracy without an external crystal - critical for HID, CDC, and vendor-class USB devices.
Typical applications include USB HID peripherals (keyboards, mice, custom input devices), USB-to-UART bridges, USB battery chargers, and low-power sensor nodes. The 1.8V minimum supply supports single-cell Li-ion or two-AA battery operation, making it suitable for portable medical, consumer, and IoT designs.
Design tip: When using the internal USB transceiver, place a 0.1 uF decoupling capacitor within 5 mm of the VUSB3V3 pin and ensure the D+/D- traces are 90 ohm differential-impedance matched for Full-Speed USB compliance.
This page consolidates current distributor pricing, drop-in same-package alternatives, and engineering design notes not found in the manufacturer datasheet alone, providing information gain beyond Microchip's product page.
Drop-in alternatives for PIC18LF25K50T-I/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 PIC18LF25K50T-I/SS (same form factor and footprint) — differing in ADC, Package, Timers, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF25K50-I/SS
✅ Drop-In✓ In Stock
$1.75 / Unit
View Datasheet →PIC18LF25K50-E/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K50-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF24K50-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K22-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18LF25K50T-I/SS Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| RAM | 2 KB |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 48 MHz (16 MIPS) |
| Operating Voltage | 1.8 V to 3.6 V |
| USB | USB 2.0 Full-Speed (12 Mbps) integrated transceiver |
| ADC | 10-bit, 25 channels |
| I/O Pins | 25 |
| Timers | 2 x 8-bit + 3 x 16-bit |
| CCP/ECCP Modules | 2 CCP + 1 ECCP |
| Communication | 2x UART, 1x SPI, 1x I2C (M/S) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-pin SSOP (5.30 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
PIC18LF25K50T-I/SS Pin Configuration
| Pin 1 | RA0 — Digital I/O / analog input AN0 / IOC |
| Pin 2 | RA1 — Digital I/O / analog input AN1 / IOC |
| Pin 3 | RA2 — Digital I/O / analog input AN2 / IOC |
| Pin 4 | RA3 — Digital I/O / analog input AN3 / IOC |
| Pin 5 | RA4 — Digital I/O / analog input AN4 / IOC |
| Pin 6 | RA5 — Digital I/O / analog input AN5 / IOC |
| Pin 7 | VDD — Positive supply voltage |
| Pin 8 | VUSB3V3 — USB internal transceiver 3.3V supply |
| Pin 9 | VSS — Ground reference |
| Pin 10 | RB7/PGD — Digital I/O / ICSP data |
| Pin 11 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 12 | RB5 — Digital I/O / analog input AN11 |
| Pin 13 | RB4 — Digital I/O / analog input AN10 |
| Pin 14 | RB3 — Digital I/O / analog input AN9 |
| Pin 15 | RB2 — Digital I/O / analog input AN8 |
| Pin 16 | RB1 — Digital I/O / analog input AN6 / IOC |
| Pin 17 | RB0 — Digital I/O / analog input AN12 / IOC |
| Pin 18 | RC7 — Digital I/O / RX2 (secondary UART) |
| Pin 19 | RC6 — Digital I/O / TX2 (secondary UART) |
| Pin 20 | D-/RC4 — USB D- data line / Digital I/O |
| Pin 21 | D+/RC5 — USB D+ data line / Digital I/O |
| Pin 22 | RC3 — Digital I/O / analog input AN15 |
| Pin 23 | RC2 — Digital I/O / analog input AN14 |
| Pin 24 | RC1 — Digital I/O / analog input AN13 |
| Pin 25 | RC0 — Digital I/O / analog input AN16 |
| Pin 26 | RA7/OSC1 — Digital I/O / crystal oscillator input |
| Pin 27 | VSS — Ground reference |
| Pin 28 | RA6/OSC2 — Digital I/O / crystal oscillator output |
Typical Applications
PIC18LF25K50T-I/SS is suitable for 6 applications: USB HID Peripheral (Keyboard/Mouse/Custom Input), USB-to-UART Bridge / CDC Virtual COM Port, USB Battery Charger / Power Bank Controller, Low-Power Sensor Node with USB Diagnostics, Industrial USB Data Logger / Tethered Sensor, USB Consumer / Toy / Educational Device.
USB HID Peripheral (Keyboard/Mouse/Custom Input)
The PIC18LF25K50T-I/SS integrated USB 2.0 Full-Speed transceiver and Active Clock Tuning make it ideal for USB HID peripherals without an external crystal. Its 32KB Flash is sufficient for HID class descriptors plus custom feature reports, while 2KB RAM comfortably handles USB endpoint buffers (8-byte EP0 plus 64-byte EP1). The 1.8V-3.6V range supports direct battery operation; the 25-channel 10-bit ADC enables analog inputs for gaming mice or environmental sensors. Place 0.1 uF decoupling within 5 mm of VUSB3V3 and route D+/D- as 90 ohm differential traces for compliance.
Recommended
USB-to-UART Bridge / CDC Virtual COM Port
The PIC18LF25K50T-I/SS dual UART plus integrated USB makes it a compact CDC bridge converting USB to RS-232 levels. With 48 MHz CPU speed the UART can run up to 1.5 Mbps, sufficient for most industrial protocols. The 25 GPIO offer spare pins for flow-control handshaking (RTS/CTS) or status LEDs. Internal USB pull-up eliminates the external resistor typical of FTDI bridges, reducing BOM cost. Designers can use Microchip's USB CDC stack for plug-and-play driverless operation on Windows/Linux/macOS.
Recommended
USB Battery Charger / Power Bank Controller
The PIC18LF25K50T-I/SS integrated USB 2.0 and 10-bit ADC support portable USB battery charger designs reading voltage and current sense from a single-cell Li-ion cell. Its 1.8V minimum supply allows direct Li-ion operation without boost regulator, maximizing efficiency. Active Clock Tuning keeps USB enumeration reliable as VDD drops during discharge. The 25-channel ADC monitors battery voltage, charge current, temperature thermistor, and load current simultaneously, while CCP modules can drive charge-control FETs with hardware PWM without CPU intervention.
Recommended
Low-Power Sensor Node with USB Diagnostics
The PIC18LF25K50T-I/SS nanoWatt XLP sleep currents below 100 nA extend battery life in remote sensor nodes that periodically wake and report data over USB. Sleep currents of 20-50 nA in Sleep mode with peripherals off are competitive with newer Cortex-M0+ parts while keeping 8-bit cost low. The ADC's 25 channels accept multiple sensors (temperature, light, motion), and 2KB RAM buffers pre-sleep acquisitions. Engineers value the same-chip USB for in-field firmware upgrade via USB without needing a separate serial bootloader.
Recommended
Industrial USB Data Logger / Tethered Sensor
Industrial data loggers use the PIC18LF25K50T-I/SS integrated USB to stream logged sensor data to a host without external UART-to-USB bridges. The 32KB Flash accommodates interrupt-driven logging firmware with ring buffer support, while 256 bytes EEPROM stores calibration parameters non-volatilely. Industrial -40C to +85C rating supports factory-floor or outdoor enclosures. The two UARTs can drive RS-485 transceivers for Modbus polling in parallel with USB diagnostic output, allowing simultaneous field-bus and tethered-host visibility.
Recommended
USB Consumer / Toy / Educational Device
Consumer USB devices (educational toys, USB prop controllers, MIDI controllers) use the PIC18LF25K50T-I/SS for its low-cost USB integration and simple PIC18 instruction set. The 48 MHz CPU handles USB interrupt rates plus real-time button scanning at USB 1 ms polling intervals without dropped packets. Microchip's free USB stack supports HID, CDC, MIDI, and vendor classes, while 32KB Flash fits customized feature reports and animation logic. Active Clock Tuning eliminates the crystal cost advantage typical of hobbyist MCU designs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF25K50T-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF25K50-I/SS | PIC18LF25K50-E/SS | PIC18F25K50-I/SS | PIC18LF24K50-I/SS | PIC18F25K22-I/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 32 KB | 32 KB | 32 KB | 32 KB | 16 KB | 32 KB |
| RAM | 2 KB | 2 KB | 2 KB | 2 KB | 1 KB | 2 KB |
| Integrated USB | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | No USB |
| Operating Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 5.5 V | 1.8 V to 3.6 V | 1.8 V to 5.5 V |
| Temperature Grade | -40C to +85C (Industrial) | -40C to +85C | -40C to +125C (Extended) | -40C to +85C | -40C to +85C | -40C to +85C |
| Max CPU Speed | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 64 MHz (16 MIPS) |
| ADC | 10-bit, 25 ch | 10-bit, 25 ch | 10-bit, 25 ch | 10-bit, 25 ch | 10-bit, 24 ch | 10-bit, 19 ch |
Key Differentiators
- Active Clock Tuning eliminates USB crystal requirement (vs PIC18F25K22-I/SS)
- Lower-voltage operation extends battery life (vs PIC18F25K50-I/SS)
- Tape-and-reel packaging for SMT production (vs PIC18LF25K50-I/SS)
Design Notes
Place a 0.1 uF decoupling capacitor within 5 mm of the VDD pin (pin 7) and a 4.7-10 uF bulk capacitor near the VUSB3V3 pin (pin 8). The internal USB transceiver is sensitive to supply noise during enumeration. Route D+ (pin 21) and D- (pin 20) as a 90 ohm differential pair with no stubs, matching the USB 2.0 Full-Speed specification. Keep the differential pair away from switching signals or clocks; recommended 3W spacing to other traces.
The internal USB regulator provides 3.3V from VDD, but at lower VDD (below 3.0V) the USB 3V3 rail droops below USB spec. For battery designs operating below 3.0V, add an external LDO (e.g., MCP1700) to drive VUSB3V3 from the battery directly. Note that when VUSB3V3 is driven externally, VDD can be as low as 1.8V for the digital core while USB signaling remains within spec.
Do not connect a 12 MHz or 48 MHz crystal when using Active Clock Tuning - the internal 48 MHz oscillator self-calibrates against USB SOF packets and an external crystal will cause clock conflicts. For designs without USB, disable Active Clock Tuning and use the HFINTOSC directly or supply an external clock on OSC1/RA7 (pin 26). Also remember to clear the CONFIG1L IESO bit if crystal mode is not used.
When designing for the SSOP variant, reserve at least 0.5 mm clearance from the package body to allow hand-rework and to maintain 150V creepage per IPC-2221 for industrial isolation. The 28-SSOP has a 0.65 mm pitch which is hand-solderable with a fine tip - the QFN variant (PIC18LF25K50T-I/ML) is 0.5 mm pitch QFN requiring reflow only. Use the SSOP for prototype rework-heavy designs.
Compliance Information
RoHS compliant per Microchip product page. Industrial -40C to +85C temperature grade; choose PIC18LF25K50-E/SS for extended -40C to +125C grade. Not AEC-Q100 qualified - automotive applications require PIC18F25K50-I/SS or a Q-graded part.
