PIC18F25K50T-I/SS - 8-Bit 48MHz 32KB Flash USB MCU | Microchip
MPN: PIC18F25K50T-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.8 | $3.80 |
| 10 | $3.42 | $34.20 |
| 100 | $2.95 | $295.00 |
| 500 | $2.65 | $1,325.00 |
| 1,000 | $2.4 | $2,400.00 |
PIC18F25K50T-I/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path, integrating CPU core, non-volatile program memory (Flash), volatile data memory (RAM), EEPROM, and a rich set of peripherals such as timers, ADC, communication interfaces, and I/O. The PIC18F25K50 belongs to the eXtreme Low Power (XLP) family, sitting in the power-management IC -> microcontroller -> 8-bit MCU -> PIC18 product-type hierarchy. Its nanoWatt XLP technology minimizes active and sleep currents, enabling battery-friendly USB peripherals.
Key differentiating features include the on-chip USB 2.0 full-speed transceiver with internal 48 MHz oscillator that achieves USB-accurate timing via Active Clock Tuning from the USB host, eliminating the need for an external crystal in many USB applications. The device provides 32 KB self-read/write Flash, 2 KB RAM, 256 B EEPROM, 22 I/O, multiple communication peripherals (I2C/SPI/EUSART), and 10-bit ADC capability with multiple Capture/Compare/PWM modules for motor and LED control. The XLP sleep currents extend battery life in always-on sensors and wearables.
Architecturally, the PIC18F25K50 uses an enhanced Harvard RISC core with 200 ns instruction cycle, hardware 8x8 multiplier, and a 16-level hardware stack. The integrated USB module, on-chip voltage regulator for bus-powered designs, and Active Clock Tuning form a tightly engineered USB subsystem. Compared to older PIC18F2550 designs, the K50 reduces external BOM by integrating the USB transceiver and trimming crystal needs.
Typical applications include USB HID peripherals (keyboards, mice, custom input devices), USB-to-UART bridges, USB sensor and data-acquisition nodes, low-power IoT endpoints, industrial control interfaces with USB diagnostics, and consumer electronics requiring a small-footprint USB device controller. The wide 2.3-5.5 V range also suits battery-powered designs using 2x AA cells or Li-ion.
When designing with this MCU, place the VUSB decoupling capacitor (typically 470 nF) close to the VUSB pin, respect USB DP/DM trace impedance (90 ohms differential), and use the internal regulator or external 3.3 V LDO for bus-powered designs. The Microchip MPLAB X IDE and XC8 compiler fully support the PIC18F25K50 family, simplifying firmware development.
This page synthesizes verified distributor pricing, drop-in alternatives from the same Microchip K50 family, and practical USB design notes not collected in any single manufacturer document.
Drop-in alternatives for PIC18F25K50T-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 PIC18F25K50T-I/SS (same form factor and footprint) — differing in Operating Temperature, Package, ADC, Core, Comparators.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F25K50-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25K50T-I/SO
✅ Drop-In✓ In Stock
$1.84 / Unit
View Datasheet →PIC18F24K50T-I/SS
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →PIC18F25K22-I/SS
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F25K42-E/SS
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC18F25K50T-I/SS Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit RISC) |
| Family | PIC XLP 18K |
| Program Memory | 32 KB Flash (16K x 16) |
| RAM | 2 KB |
| EEPROM | 256 B |
| Maximum CPU Speed | 48 MHz |
| Instruction Cycle | 200 ns (at 48 MHz, 4 cycles/instruction) |
| Supply Voltage | 2.3 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) |
| I/O Pins | 22 |
| USB | USB 2.0 Full-Speed transceiver on-chip |
| Internal Oscillator | 48 MHz (USB-accurate via Active Clock Tuning) |
| Package | 28-pin SSOP (5.30 mm body width) |
| Mounting Type | Surface Mount |
| MSL Level | MSL 1 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18F25K50T-I/SS Pin Configuration
| Pin 1 | RA0/AN0/C1IN+/C2IN+/UPD+ — Bidirectional I/O / analog input / USB D+ (on selected variants) |
| Pin 2 | RA1/AN1/C12IN1-/C2IN+ — Bidirectional I/O / analog input |
| Pin 3 | RA2/AN2/VREF-/C2IN- — Bidirectional I/O / analog input / negative reference |
| Pin 4 | RA3/AN3/VREF+/C1IN0- — Bidirectional I/O / analog input / positive reference |
| Pin 5 | RA4/CCP5/SOSC1/T1G — Bidirectional I/O / Capture Compare / secondary oscillator |
| Pin 6 | RA5/CCP4/SOSC2/T1CKI — Bidirectional I/O / Capture Compare / secondary oscillator / Timer1 clock |
| Pin 7 | RA6/CCP3/OSC2/CLKOUT — Bidirectional I/O / Capture Compare / crystal / clock out |
| Pin 8 | RA7/OSC1/CLKIN — Bidirectional I/O / crystal / clock in |
| Pin 9 | VDD — Positive supply voltage (2.3-5.5 V) |
| Pin 10 | VSS — Ground reference |
| Pin 11 | D+ — USB D+ data line (full-speed) |
| Pin 12 | D- — USB D- data line (full-speed) |
| Pin 13 | VUSB — USB internal regulator decoupling output (470 nF to VSS) |
| Pin 14 | RC0/SOSCO — Bidirectional I/O / secondary oscillator output |
| Pin 15 | RC1/SOSCI/CCP2 — Bidirectional I/O / secondary oscillator input / Capture Compare |
| Pin 16 | RC2/CCP1 — Bidirectional I/O / Capture Compare PWM |
| Pin 17 | RC3/SEG7/CCP9 — Bidirectional I/O / LCD segment / Capture Compare |
| Pin 18 | RC4/D-/VMO — Bidirectional I/O / USB D- (alternate) |
| Pin 19 | RC5/D+/VPO — Bidirectional I/O / USB D+ (alternate) |
| Pin 20 | RC6/AN8/TX/CK — Bidirectional I/O / analog / EUSART TX |
| Pin 21 | RC7/AN9/RX/DT — Bidirectional I/O / analog / EUSART RX |
| Pin 22 | RB0/AN10/INT0/FLT0 — Bidirectional I/O / analog / external interrupt 0 |
| Pin 23 | RB1/AN11/INT1 — Bidirectional I/O / analog / external interrupt 1 |
| Pin 24 | RB2/AN12/INT2/CTPLS — Bidirectional I/O / analog / external interrupt 2 |
| Pin 25 | RB3/AN9/CPP2 — Bidirectional I/O / analog / Capture Compare |
| Pin 26 | RB4/AN11/KBI0 — Bidirectional I/O / analog / keyboard interrupt |
| Pin 27 | RB5/AN13/KBI1/PGM — Bidirectional I/O / analog / keyboard interrupt / LVP programming |
| Pin 28 | RB6/ICSPCLK/KBI2/PGC — Bidirectional I/O / ICSP clock / keyboard interrupt / debug clock |
Typical Applications
PIC18F25K50T-I/SS is suitable for 6 applications: USB HID Peripherals (Keyboard, Mouse, Custom Input), USB-to-UART Bridge and COM Port Adapters, Low-Power IoT Sensors with USB Diagnostics, Industrial Control Interfaces with USB Service Port, Consumer Electronics with USB Charging/Status, USB Data Acquisition and Test Pods.
USB HID Peripherals (Keyboard, Mouse, Custom Input)
The PIC18F25K50T-I/SS's on-chip USB 2.0 full-speed transceiver and 48 MHz internal oscillator with Active Clock Tuning make it an ideal main MCU for USB HID class peripherals such as keyboards, mice, game controllers, and custom input devices. Its 32 KB Flash comfortably stores USB HID report descriptors, keymaps, and small state machines, while the 22 I/O pins handle matrix scanning, LED indication, and capacitive touch sensing. Unlike MCUs that require an external USB PHY or crystal, this part reduces BOM and PCB area. Design tip: enable USB regulator in bus-powered mode and route DP/DM as a 90 ohm differential pair per USB 2.0 spec.
Recommended
USB-to-UART Bridge and COM Port Adapters
The PIC18F25K50T-I/SS is widely deployed as a USB-to-UART bridge, emulating CDC ACM class devices to present a virtual COM port on any USB-capable host. The integrated USB, EUSART peripheral, 48 MHz CPU, and 32 KB Flash provide ample throughput for baud rates up to 921600 with hardware flow control, while the 2 KB RAM buffers short bursts without flow control stalls. Its 2.3-5.5 V range means the same firmware can drive 3.3 V or 5 V logic levels on the UART side, useful for legacy MCUs. Compared to dedicated bridges like MCP2200, the K50 adds programmable GPIO for status LEDs and pushbuttons.
Recommended
Low-Power IoT Sensors with USB Diagnostics
Battery-powered IoT sensors that periodically connect to USB for firmware update or diagnostics benefit from the PIC18F25K50T-I/SS's nanoWatt XLP technology, which delivers sub-microamp sleep currents. The MCU can sleep for years on a single CR2032 cell while remaining available for USB attach, and the 48 MHz Active Clock Tuning eliminates the parasitic drain of an always-on external crystal. The 22 I/O pins drive I2C/SPI sensors, while the integrated 10-bit ADC reads analog channels. This part is a strong fit for asset trackers, environmental monitors, and BLE-dongle-style devices that pair sensor data with USB provisioning.
Recommended
Industrial Control Interfaces with USB Service Port
Industrial controllers and HMIs use the PIC18F25K50T-I/SS as a USB service port to expose configuration, log download, and firmware update over USB without adding a separate serial connector. The 2.3-5.5 V supply range tolerates noisy 24 V-derived rails with simple LDOs, and the -40C to +85C industrial temperature grade survives factory floor environments. The 22 I/O pins drive relays, optocouplers, and keypads; the EUSART can multiplex RS-485 alongside USB. Compared to external USB bridges, integrating USB on the main MCU simplifies the BOM and avoids chip-to-chip handshake latency.
Recommended
Consumer Electronics with USB Charging/Status
Consumer devices such as toys, personal care electronics, and audio accessories use the PIC18F25K50T-I/SS as a USB-attached microcontroller that handles charging indicator LEDs, button decoding, and USB status reporting. The 32 KB Flash holds small graphical or audio playback routines, while the Capture/Compare/PWM modules generate precise LED dimming and audio tones. The 48 MHz CPU is fast enough for software USB HID or CDC, leaving resources for capacitive touch via the ADC. Compared to low-pin PIC12/16 cousins, the K50 provides the USB and PWM mix in a single IC, reducing PCB area.
Recommended
USB Data Acquisition and Test Pods
USB data-acquisition pods and bench-test instruments use the PIC18F25K50T-I/SS as the bridge between analog sensors and the host PC, leveraging its 10-bit ADC, multiple timers, and USB full-speed link. Streaming 8 kSPS with 22 I/O is feasible inside the 2 KB RAM with double-buffered firmware, while the 48 MHz CPU handles 115200-equivalent isochronous data flows. The wide operating voltage allows direct connection to 3.3 V or 5 V sensor boards. Unlike dedicated USB ADC ICs, the K50 allows programmable gain, calibration, and per-channel signal conditioning in firmware, ideal for laboratory and field test gear.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F25K50T-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F25K50-I/SS | PIC18F25K50T-I/SO | PIC18F24K50T-I/SS | PIC18F25K22-I/SS | PIC18F25K42-E/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) | 28-SOIC (7.50 mm) | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 16 KB (-50%) | 32 KB | 32 KB |
| RAM | 2 KB | 2 KB | 2 KB | 1 KB (-50%) | 1.5 KB (-25%) | 2 KB |
| Maximum CPU Speed | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 64 MHz (+33%) | 64 MHz (+33%) |
| USB Module | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | No USB | No USB |
| I/O Pins | 22 | 22 | 22 | 22 | 24 (+2) | 25 (+3) |
| Operating Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Internal Oscillator | 48 MHz + USB ACT | 48 MHz + USB ACT | 48 MHz + USB ACT | 48 MHz + USB ACT | 16 MHz (no USB ACT) | 64 MHz (no USB ACT) |
Key Differentiators
- Integrated USB 2.0 full-speed transceiver with no external crystal (vs PIC18F25K22-I/SS)
- Higher Flash density than the 24K50 sibling for firmware-heavy designs (vs PIC18F24K50T-I/SS)
- Industrial-grade -40C to +85C operating range with full USB characterization (vs PIC18F25K42-E/SS)
Design Notes
USB DP/DM traces MUST be routed as a 90 ohm differential pair with controlled impedance, kept short and away from noisy signals. The VUSB pin requires a 470 nF (typical) decoupling capacitor placed within 5 mm of the pin to ground, or USB enumeration will fail. If the application is bus-powered (drawing >100 mA from VBUS), enable the internal 3.3 V USB regulator and tie D+/D- to the host through proper ESD protection diodes - omitting these is the #1 cause of USB compliance failures.
Although the PIC18F25K50T-I/SS uses nanoWatt XLP for low sleep current, USB suspend mode draws <2.5 mA and is regulated by the host - firmware must enter USB suspend within 10 ms of host suspend signaling to remain compliant. Decouple VDD with 100 nF + 10 uF bulk capacitors placed close to the VDD/VSS pins (pin 9 and pin 10). For battery-powered designs, use the internal voltage regulator off-mode to drop quiescent current below 1 uA between USB events.
Place the ICSP pins (RB6/PGC and RB7/PGD) on test pads or a 2x3 header for in-circuit programming and debugging. Add a 10 kohm pull-up on MCLR (pin 1) unless internal pull-up is configured. For the 28-SSOP footprint, use a 1.0 mm pitch land pattern with at least 0.3 mm annular ring; SSOP thermal pad is not present so copper pour on pin 9/10 (VDD/VSS) is acceptable but not required.
Isolate the 48 MHz oscillator region from analog inputs: keep the crystal (if used) within 5 mm of OSC1/OSC2 (pins 8 and 7), and route analog signals RA0-RA3 perpendicular to digital buses. The D+/D- differential pair should not cross any clock or switching signal. For EMI compliance, add a common-mode choke on D+/D- if the cable exceeds 1 m, and ensure the USB shield returns to chassis ground at the connector only (single-point ground).
Active Clock Tuning (ACT) locks the internal 48 MHz oscillator to the USB host frame timing - firmware must enable ACT after every USB reset for full-speed compliance. Without ACT, internal 48 MHz drift of +/- 2% over temperature may violate USB jitter masks. Designers can verify ACT status via the ACTCON register; if ACT fails to lock, the firmware should fall back to an external 48 MHz clock source for reliable enumeration.
Compliance Information
RoHS and REACH compliant per Microchip product page. Lead-free reflow profile per JEDEC J-STD-020 MSL1. AEC-Q100 not applicable - this is a consumer/industrial MCU. Conflict minerals declaration available on Microchip corporate responsibility page.
