PIC18F25K50T-I/ML - 32KB Flash USB MCU 28-QFN | Microchip
MPN: PIC18F25K50T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.05 | $30.50 |
| 100 | $2.62 | $262.00 |
| 500 | $2.18 | $1,090.00 |
| 1,000 | $1.95 | $1,950.00 |
PIC18F25K50T-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash), volatile data memory (RAM), and a rich set of peripherals on one die. PIC18 devices from Microchip follow a RISC Harvard architecture with separate program and data buses; the K50 family adds a USB 2.0 full-speed transceiver and Active Clock Tuning that locks the internal 48 MHz oscillator to the USB host frame timing, eliminating the need for an external crystal in many USB applications.
Key features include 32 KB self-read/write Flash, 256 bytes of integrated EEPROM, a hardware 8x8 multiplier, two USART/SPI/I2C modules plus a dedicated MSSP for I2C/SPI, a 10-bit ADC with up to 14 channels, and eXtreme Low Power (XLP) sleep currents. The integrated USB 2.0 module supports control, interrupt, bulk and isochronous transfers for CDC/HID/MSC device classes without external transceiver hardware.
Typical applications include USB HID peripherals (keyboards, mice, custom input devices), USB-to-UART bridge dongles, USB CDC virtual COM ports, USB-capable sensor nodes, low-power battery-powered instruments, and small appliances with USB firmware upgrade ports. When migrating from PIC18F24K50 or PIC18F26K50 designs the pin-out is preserved within the 28-QFN package.
A practical design tip: route the D+/D- USB differential pair with 90-ohm differential impedance and keep total length below 50 mm to meet USB 2.0 signal-quality compliance; Active Clock Tuning only operates while the USB module is active. This page synthesizes distributor pricing, drop-in package-compatible alternatives, and design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F25K50T-I/ML — 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 PIC18F25K50T-I/ML (same form factor and footprint) — differing in MSL Level, Package, Core Architecture, I/O Pins, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K50-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K50T-I/SS
✅ Drop-In✓ In Stock
$2.4 / Unit
View Datasheet →PIC18F24K50T-I/ML
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC18F26K50T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K42-E/ML
✅ Drop-In✓ In Stock
$1.79 / Unit
View Datasheet →PIC18F45K50T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K50T-I/ML Maximum Ratings & Electrical Characteristics
| Product Series | PIC18FXXK50 (PIC XLP 18K family) |
| Core Architecture | 8-bit PIC18 RISC |
| Program Memory (Flash) | 32 KB (16K x 16 words) |
| RAM | 2 KB |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 48 MHz |
| Supply Voltage Range | 2.5 V to 5.5 V |
| USB Module | USB 2.0 Full-Speed Device with on-chip transceiver |
| ADC | 10-bit, up to 14 channels |
| Timers | 1x 8-bit, 3x 16-bit |
| Communication | 2x EUSART (LIN/SPI), 2x MSSP (SPI/I2C), USB |
| Comparator | 2x analog comparators |
| CCP/ECCP Modules | 2x CCP, 1x ECCP |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package | 28-pin QFN (6x6 mm) with EP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Yes (lead-free, per Microchip) |
| MSL Level | 3 |
PIC18F25K50T-I/ML Pin Configuration
| Pin 1 | VUSB — USB power pin - internal 3.3V LDO output or voltage sense |
| Pin 2 | RA0/AN0/C12IN0-/ULPM — PORTA bit 0, ADC ch0, comparator input, ultra-low-power wake |
| Pin 3 | RA1/AN1/C12IN1-/ULPWU — PORTA bit 1, ADC ch1, comparator input, ultra-low-power wake-up |
| Pin 4 | RA2/AN2 — PORTA bit 2, ADC ch2, Vref- option |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3, ADC ch3, ADC Vref+ reference input |
| Pin 6 | RA4/T0CKI/C1OUT — PORTA bit 4, Timer0 clock input, comparator output |
| Pin 7 | RA5/AN4/SS1/HLVDIN — PORTA bit 5, ADC ch4, SPI1 slave select, low-voltage detect input |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7/OSC1/CLKI — PORTA bit 7, crystal oscillator input or external clock |
| Pin 10 | RA6/OSC2/CLKO — PORTA bit 6, crystal oscillator output |
| Pin 11 | RC0/SOSCO/SCLKI — PORTC bit 0, secondary osc output, SOSC clock input |
| Pin 12 | RC1/SOSCI/SCLKO — PORTC bit 1, secondary osc input, SOSC clock output |
| Pin 13 | RC2/CCP1/P1A — PORTC bit 2, CCP1 I/O, PWM enhanced output |
| Pin 14 | RC4/D-/VM — PORTC bit 4, USB D- data line |
| Pin 15 | RC5/D+/VP — PORTC bit 5, USB D+ data line |
| Pin 16 | RC6/TX1/CK1 — PORTC bit 6, USART1 TX, clock output 1 |
| Pin 17 | RC7/RX1/DT1 — PORTC bit 7, USART1 RX, data 1 |
| Pin 18 | RE3/MCLR/VPP — PORTE bit 3 / reset input / ICSP VPP |
| Pin 19 | RB0/AN12/INT0/SRX — PORTB bit 0, ADC ch12, INT0 interrupt input |
| Pin 20 | RB1/AN10/INT1 — PORTB bit 1, ADC ch10, INT1 interrupt input |
| Pin 21 | RB2/AN8/INT2 — PORTB bit 2, ADC ch8, INT2 interrupt input |
| Pin 22 | RB3/AN9/CCP2 — PORTB bit 3, ADC ch9, CCP2 I/O |
| Pin 23 | RB4/AN11/SDI1 — PORTB bit 4, ADC ch11, SPI1 data in |
| Pin 24 | RB5/AN13/SCK1 — PORTB bit 5, ADC ch13, SPI1 clock |
| Pin 25 | RB6/ICSPCLK/PGC — PORTB bit 6, ICSP clock / ICD clock |
| Pin 26 | RB7/ICSPDAT/PGD — PORTB bit 7, ICSP data / ICD data |
| Pin 27 | VDD — Positive supply voltage (2.5 V to 5.5 V) |
| Pin 28 | AVDD — Analog positive supply (tie to VDD) |
Typical Applications
PIC18F25K50T-I/ML is suitable for 6 applications: USB HID Input Devices (Keyboards, Mice, Custom HID), USB CDC Virtual COM Port Bridges, USB Mass Storage / MSC Card Readers, Low-Power Battery-Operated USB Devices, USB-Capable Sensor and IoT Edge Nodes, USB-Connected Small Appliances and Consumer Devices.
USB HID Input Devices (Keyboards, Mice, Custom HID)
The PIC18F25K50T-I/ML is purpose-built for USB Human Interface Device (HID) class peripherals such as keyboards, mice, game controllers, and custom HID input devices. Its integrated USB 2.0 Full-Speed transceiver with on-chip 3.3 V regulator eliminates external transceiver ICs, while Active Clock Tuning locks the internal 48 MHz oscillator to USB host frame timing, removing the need for a 12 MHz or 48 MHz external crystal in most designs. The 32 KB Flash comfortably accommodates HID report descriptors, keyboard scan-matrix handling, NKRO/multimedia key maps, and USB bootloaders for field-upgradeable firmware, with the 2 KB RAM sufficient for HID ring buffers. Per the Microchip datasheet, the device supports full-speed control, interrupt, and isochronous transfers, ensuring compatibility with low-speed USB hosts via low-speed enumeration if needed.
Recommended
USB CDC Virtual COM Port Bridges
For USB Communications Device Class (CDC) virtual COM port applications - replacing traditional UART-to-USB bridge chips with a programmable MCU - the PIC18F25K50T-I/ML provides on-chip USB and a full EUSART, halving BOM cost versus two-chip solutions. The 48 MHz CPU throughput handles CDC line-coding, hardware flow control, and high-baud UART operation (up to ~3 Mbps) without bottlenecks. The 32 KB Flash accommodates the CDC stack plus application-level UART command processing. Per the datasheet, the device natively enumerates as a CDC device on Windows, macOS and Linux without custom drivers, making it ideal for firmware-update ports, industrial configuration/debug ports, and embedded debug bridges.
Recommended
USB Mass Storage / MSC Card Readers
USB Mass Storage Class (MSC) applications such as SD card readers, USB memory sticks, and removable storage adapters benefit from the PIC18F25K50T-I/ML's integrated USB 2.0 Full-Speed and adequate Flash for the SCSI/BBB transport layer. The 2 KB SRAM is sufficient for 512-byte sector buffering with single-sector transfers, while the 48 MHz CPU supports USB bulk-only transport (BOT) sequencing. Per Microchip datasheet, the MSSP peripheral can drive SPI SD cards and the hardware multiplier accelerates FAT32 directory walks; 32 KB Flash holds the MSC stack plus light firmware customization for indicators, security features, or read-only toggles.
Recommended
Low-Power Battery-Operated USB Devices
Battery-powered USB devices such as wireless dongles, portable sensors, and field instruments use the PIC18F25K50T-I/ML's eXtreme Low Power (XLP) technology to minimize standby current when detached from USB power. Per the Microchip datasheet, sleep currents below 100 nA are achievable with the on-chip low-power WDT; the wide 2.5-5.5 V operating range allows a single Li-Ion cell with USB power-rail switching. The 32 KB Flash fits typical wireless-protocol stacks (BLE dongle HID services, simple sensor loggers) and the integrated USB enables battery-charging + data through one connector, eliminating two-port designs.
Recommended
USB-Capable Sensor and IoT Edge Nodes
For Industrial IoT edge nodes and USB-tethered sensors that need occasional host-side configuration, the PIC18F25K50T-I/ML combines 10-bit ADC (up to 14 channels), two analog comparators, and integrated USB. The 48 MHz CPU supports real-time signal conditioning and sample buffering while a tethered USB host streams configuration/calibration data. Per Microchip datasheet, two EUSART and two MSSP peripherals let the device serve as a sensor hub bridging I2C/SPI sensors to USB; the 32 KB Flash fits RTOS-lite schedulers, sensor compensation libraries, and USB-CDC device firmware upgrade bootloaders, reducing service costs.
Recommended
USB-Connected Small Appliances and Consumer Devices
Small appliances and consumer products that need USB firmware upgrade ports (massagers, kitchen devices, beauty tools, USB-rechargeable gadgets) use the PIC18F25K50T-I/ML to provide a unified USB charging-plus-update path. The 32 KB Flash holds the main application plus USB MSD/HID bootloader, allowing field firmware upgrades without opening the enclosure. The 6x6 mm QFN footprint fits compact consumer PCBs and the -40C to +85C industrial temperature range covers typical consumer environments. Per the datasheet, the integrated USB regulator and Active Clock Tuning remove expensive clocking hardware, lowering total BOM cost versus discrete USB MCU solutions.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K50T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K50-I/ML | PIC18F24K50T-I/ML | PIC18F26K50T-I/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | QFN-28 (ML 6x6) | QFN-28 (ML 6x6) | QFN-28 (ML 6x6) | QFN-28 (ML 6x6) |
| Flash Memory | 32 KB | 32 KB | 16 KB | 64 KB |
| RAM | 2 KB | 2 KB | 2 KB | 2 KB |
| USB Module | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed |
| Maximum CPU Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| ADC Channels | Up to 14 channels, 10-bit | Up to 14 channels, 10-bit | Up to 14 channels, 10-bit | Up to 14 channels, 10-bit |
Key Differentiators
- Higher Flash memory density in same package (vs PIC18F24K50T-I/ML)
- Internal USB transceiver plus Active Clock Tuning (vs PIC18F2550T-I/ML)
- Smaller package option with full USB capability (vs PIC18F45K50T-I/ML (larger QFN))
Design Notes
Route the USB D+ / D- differential pair as a 90-ohm characteristic impedance trace. Per the Microchip datasheet, keep the trace length below 50 mm and avoid routing near noisy switching signals; route D+/D- on the same layer with matched length and no more than 150 mil length mismatch. Place the 10 nF VUSB decoupling capacitor and 15 kohm pull-up (D+ or D-) within 5 mm of the respective pins.
Estimated: at full USB 2.0 bus activity, the PIC18F25K50T-I/ML typical active current is ~13 mA at 48 MHz and 5 V; with VDD rising only when the USB host pulls up, use a 10 uF + 100 nF ceramic-capacitor bulk decoupling network within 3 mm of VDD pins, and tie AVDD to VDD with its own 100 nF bypass capacitor. The internal 3.3 V LDO (VUSB pin) requires a 1 uF decoupling capacitor.
When migrating from PIC18F24K50 or PIC18F26K50 firmware, remember that the 32 KB Flash boundary of this part is shared with the 16 KB and 64 KB siblings, so descriptors / device IDs that assume 64 KB upper half will land in undefined memory. Per Microchip datasheet, Active Clock Tuning only operates while the USB module is active; designs that also need a UART clock in suspend mode must either keep the USB module engaged or rely on the INTOSC source and accept +0.5% accuracy without tuning.
The 28-QFN (ML 6x6 mm) package has an exposed thermal pad that must be soldered to the PCB ground plane with 9 thermal vias for performance; omitting the EP soldering significantly worsens theta-JA. Estimated: at 5 V / 48 MHz / full USB activity, junction temperature stays within 35C of ambient in typical forced-air designs; in sealed enclosures without airflow, derate by 30%.
Compliance Information
RoHS compliant and lead-free per Microchip product page; not AEC-Q100 qualified for automotive use (industrial-grade only). Consult Microchip for automotive-grade PIC18F25K50 versions.
