PIC18F45K50-I/PT - 8-bit USB MCU, 32KB Flash, 48MHz, TQFP-44 | Microchip
MPN: PIC18F45K50-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.42 | $342.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.74 | $2,740.00 |
PIC18F45K50-I/PT Overview
An 8-bit microcontroller (MCU) is a programmable processor that executes one byte of data per instruction cycle and is typically selected for cost-sensitive, deterministic embedded control. Within the broader taxonomy, the PIC18F45K50 sits in the microcontroller -> 8-bit MCU -> PIC18 family -> PIC18F K-series chain, and combines general-purpose I/O with dedicated USB, ADC, and PWM peripherals. The integrated XLP (eXtreme Low Power) technology from Microchip is what differentiates this family from earlier PIC18F devices by offering nanoWatt sleep currents in the order of tens of nA.
Key features include an internal 48 MHz oscillator accurate to within 0.25% after USB host tuning, 36 digital I/O pins, a 10-bit ADC with up to 25 input channels, two analog comparators, two 8-bit timers and three 16-bit timers, two CCP modules plus one Enhanced CCP, an integrated 5-bit DAC, and a CTMU charge-time measurement unit. The USB 2.0 Full-Speed transceiver is on-chip with internal pull-up resistors, and Active Clock Tuning from the USB host corrects oscillator drift automatically, enabling crystal-less USB designs.
Architecturally, the PIC18F45K50 uses an enhanced Harvard RISC core with an 8x8 hardware multiplier, hardware read/write Flash, and a separate peripheral bus. Compared with the older PIC18F4550 family, this K50 generation reduces sleep current by roughly 90%, removes some legacy analog modules, and adds native Active Clock Tuning for USB. The device is pin-compatible with the PIC18LF4550 footprint, so existing 44-pin TQFP layouts can be migrated with only firmware changes per Microchip's migration guide.
Typical applications include USB HID peripherals such as keyboards, mice, and custom HID-class devices, CDC virtual COM port bridges, low-cost data loggers, capacitive touch keypads using the CTMU, and small industrial sensors that need USB diagnostic connectivity. The XLP sleep modes also make it suitable for battery-powered edge nodes that wake on a USB attach event or external interrupt.
When designing with this device, budget the VUSB 3.3 V regulator current carefully and add the recommended 220 nF VUSB bypass capacitor as specified in the datasheet typical application circuit. Program development is supported by the MPLAB X IDE, MPLAB Code Configurator (MCC), and the XC8 compiler, and firmware is loaded via ICSP or the high-voltage ICSP entry mode.
This page synthesises distributor pricing, drop-in same-package alternatives, and practical design notes drawn from the Microchip datasheet and the PIC18F4550-to-PIC18F45K50 migration guide, information that is not aggregated on a single OEM or distributor page.
Drop-in alternatives for PIC18F45K50-I/PT — 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 PIC18F45K50-I/PT (same form factor and footprint) — differing in Timers, ADC, Package, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45K50-I/MV
✅ Drop-In✓ In Stock
$2.2 / Unit
View Datasheet →PIC18LF45K50-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F45K42-I/PT
✅ Drop-In✓ In Stock
$1.52 / Unit
View Datasheet →PIC18F45K22-I/PT
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F4550-I/PT
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC18F45K50-I/PT Maximum Ratings & Electrical Characteristics
| Product Family | PIC18F K-series (XLP) |
| Core | PIC18 8-bit RISC (Harvard) |
| Maximum CPU Frequency | 48 MHz (12 MIPS) |
| Program Memory (Flash) | 32 KB (16K x 16) |
| Data RAM | 2 KB |
| Data EEPROM | 256 B |
| Operating Voltage (VDD) | 2.3 V to 5.5 V |
| USB Transceiver | USB 2.0 Full-Speed (12 Mb/s), on-chip |
| Internal Oscillator | 48 MHz, USB-tunable (ACT) |
| Digital I/O Pins | 36 |
| ADC | 10-bit, up to 25 channels |
| Timers | 2x 8-bit + 3x 16-bit |
| CCP / ECCP | 2 CCP + 1 ECCP |
| Comparators / DAC / CTMU | 2 / 1 (5-bit) / 1 |
| Package | 44-pin TQFP (10 x 10 mm, PT) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free / MSL | Lead-Free, MSL3 (per Microchip tray pack) |
PIC18F45K50-I/PT Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input, or digital I/O RE3 |
| Pin 2 | RA0/AN0 — Digital I/O RA0 / analog input AN0 |
| Pin 3 | RA1/AN1 — Digital I/O RA1 / analog input AN1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O RA2 / analog input AN2 / DAC negative reference |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O RA3 / analog input AN3 / DAC positive reference |
| Pin 6 | RA4/AN4 — Digital I/O RA4 / analog input AN4 |
| Pin 7 | RA5/AN5 — Digital I/O RA5 / analog input AN5 |
| Pin 8 | RE0 — Digital I/O RE0 |
| Pin 9 | RE1 — Digital I/O RE1 |
| Pin 10 | RE2 — Digital I/O RE2 |
| Pin 11 | VDD — Positive supply (2.3 V to 5.5 V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/RA7 — Crystal input or digital I/O RA7 |
| Pin 14 | OSC2/RA6 — Crystal output or digital I/O RA6 |
| Pin 15 | RC0 — Digital I/O RC0 |
| Pin 16 | RC1 — Digital I/O RC1 |
| Pin 17 | RC2 — Digital I/O RC2 |
| Pin 18 | VUSB — Internal USB 3.3 V regulator output (decouple with 220 nF) |
| Pin 19 | RC4 — Digital I/O RC4 |
| Pin 20 | RC5 — Digital I/O RC5 |
| Pin 21 | RC6 — Digital I/O RC6 / TX on USART |
| Pin 22 | RC7 — Digital I/O RC7 / RX on USART |
| Pin 23 | D- — USB D- line |
| Pin 24 | D+ — USB D+ line |
| Pin 25 | RB0/AN12 — Digital I/O RB0 / analog input AN12 / interrupt-on-change |
| Pin 26 | RB1/AN10 — Digital I/O RB1 / analog input AN10 / CTMU |
| Pin 27 | RB2/AN8 — Digital I/O RB2 / analog input AN8 / CTMU |
| Pin 28 | RB3/AN9 — Digital I/O RB3 / analog input AN9 / CTMU |
| Pin 29 | RB4/AN11 — Digital I/O RB4 / analog input AN11 / CTMU / IOC |
| Pin 30 | RB5/AN13 — Digital I/O RB5 / analog input AN13 / CTMU / IOC |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply (2.3 V to 5.5 V) |
| Pin 33 | RB6/PGC — Digital I/O RB6 / ICD clock / ICSP clock |
| Pin 34 | RB7/PGD — Digital I/O RB7 / ICD data / ICSP data |
| Pin 35 | RD0 — Digital I/O RD0 |
| Pin 36 | RD1 — Digital I/O RD1 |
| Pin 37 | RD2 — Digital I/O RD2 |
| Pin 38 | RD3 — Digital I/O RD3 |
| Pin 39 | RD4 — Digital I/O RD4 |
| Pin 40 | RD5 — Digital I/O RD5 |
| Pin 41 | RD6 — Digital I/O RD6 |
| Pin 42 | RD7 — Digital I/O RD7 |
| Pin 43 | VSS — Ground reference (multiple VSS pins) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC18F45K50-I/PT is suitable for 6 applications: USB HID Peripherals (Keyboard / Mouse / Custom HID), USB CDC Virtual COM Port Bridge, Capacitive Touch Keypad (CTMU), Low-Cost USB Data Logger, Industrial Sensor with USB Diagnostic Port, Educational / Hobby Development Board.
USB HID Peripherals (Keyboard / Mouse / Custom HID)
The PIC18F45K50-I/PT is a natural fit for USB HID-class devices because it integrates a USB 2.0 Full-Speed transceiver, internal pull-up resistors, and Active Clock Tuning that allows crystal-less 12 Mb/s operation. At 48 MHz the CPU executes 12 MIPS, which comfortably handles USB polling plus HID report composition at 1 kHz. A 220 nF VUSB bypass capacitor and a 10 uF bulk cap are the only hardware requirements called out in the datasheet typical application circuit. Compared with a discrete USB bridge plus an 8-bit MCU, the K50 reduces BOM cost and PCB area while keeping firmware fully in MPLAB XC8.
Recommended
USB CDC Virtual COM Port Bridge
For legacy RS-232 equipment that needs a transparent USB-to-UART bridge, the PIC18F45K50-I/PT runs Microchip's CDC class firmware and presents a virtual COM port on the host. The 2 KB RAM is sufficient for 256-byte CDC IN/OUT buffers plus stack, and the 48 MHz core delivers the 12 Mbps USB Full Speed throughput required. Designers should reserve pin RC6/RC7 (or RB6/RB7) for UART to the legacy device, and enable the internal USB pull-up via the UCFG register. This application benefits from the same Microchip CDC stack used on the PIC18F4550 family.
Recommended
Capacitive Touch Keypad (CTMU)
The PIC18F45K50-I/PT integrates a CTMU (Charge-Time Measurement Unit) that enables robust capacitive touch sensing without external touch ICs. With the 48 MHz core the CTMU can sample up to 36 I/O channels at >100 Hz, which is more than enough for a 12-key keypad. The 5-bit DAC and two comparators can also drive a piezo buzzer for haptic feedback. Power consumption in deep sleep drops below 100 nA, so battery-powered remote controls can run for years on a single coin cell.
Recommended
Low-Cost USB Data Logger
For USB-attached sensor loggers, the PIC18F45K50-I/PT combines 32 KB Flash, 256 B EEPROM for non-volatile logging, and 2 KB RAM for sample buffering, all in a 44-pin TQFP. The on-chip 10-bit ADC with up to 25 input channels handles thermocouples, RTDs (via excitation), and general analog sensors. USB Full Speed allows 12 Mbps streaming to the host, while the XLP deep-sleep modes (down to ~50 nA) extend battery life between USB connect events. This combination is rare in this price tier and is the K50's main competitive advantage.
Recommended
Industrial Sensor with USB Diagnostic Port
Industrial 24V sensors often need a USB diagnostic port for field service without adding a separate USB MCU. The PIC18F45K50-I/PT's 2.3-5.5 V VDD range lets it run directly off a regulated 3.3 V or 5 V rail, and the industrial -40 C to +85 C temperature grade meets most factory floor requirements. The on-chip comparators and PWM can drive a status LED and a 4-20 mA loop while USB remains idle. Field engineers connect a laptop, run the host utility, and read internal diagnostic counters without opening the enclosure.
Recommended
Educational / Hobby Development Board
The PIC18F45K50-I/PT is widely adopted on Microchip Curiosity and XLP starter boards because it combines a complete 8-bit development platform with on-board USB programming, freeing students from needing an external PICkit. The 44-pin TQFP exposes 36 I/O on standard 0.1 inch headers, and the on-chip USB lets students build USB-aware firmware immediately. The XLP sleep modes also let introductory courses teach low-power design without additional hardware. Hobbyists can program the device with the free MPLAB X IDE and XC8 compiler.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F45K50-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45K50-I/MV | PIC18LF45K50-I/PT | PIC18F45K42-I/PT | PIC18F45K22-I/PT | PIC18F4550-I/PT |
|---|---|---|---|---|---|---|
| Package | TQFP-44 (PT) | TQFP-44 (MV) | TQFP-44 (PT) | TQFP-44 (PT) | TQFP-44 (PT) | TQFP-44 (PT) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 64 MHz | 64 MHz | 48 MHz |
| Program Flash | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| Data RAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| USB 2.0 Full Speed | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | No | Yes (on-chip) |
| Operating Voltage VDD | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 1.8 V to 3.6 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 4.2 V to 5.5 V |
| Deep-Sleep Current (XLP) | ~50 nA typical | ~50 nA typical | ~50 nA typical | ~30 nA typical | ~30 nA typical | ~1 uA (no XLP) |
| ADC | 10-bit, up to 25 channels | 10-bit, up to 25 channels | 10-bit, up to 25 channels | 12-bit, up to 28 channels | 10-bit, up to 28 channels | 10-bit, up to 13 channels |
| Approx 1000-pc Price (USD, as of 2026-09-28) | $2.74 | $2.85 | $2.95 | $2.65 | $2.45 | $3.55 |
Key Differentiators
- Crystal-less USB with Active Clock Tuning (vs PIC18F4550-I/PT)
- Lower deep-sleep current vs legacy PIC18F (vs PIC18F4550-I/PT)
- Pin-compatible upgrade path to 64 MHz K42 (vs PIC18F45K22-I/PT)
- Wider operating voltage range than legacy 5V-only 4550 (vs PIC18F4550-I/PT)
Design Notes
Decouple VUSB (pin 18) with a 220 nF low-ESR ceramic capacitor placed as close to the pin as possible, per the Microchip datasheet typical application circuit. Connect VUSB to the internal USB 3.3 V regulator output and never tie it directly to VDD. If VDD drops below 3.0 V, the USB peripheral may fail to enumerate; in that case use an external 3.3 V regulator for VUSB. Both VDD pins (11 and 32) and all VSS pins (12, 31, 43) must be connected with wide traces or a ground/power plane.
Do not assume the PIC18F45K50-I/PT is a drop-in replacement for the PIC18F4550 without firmware changes. Per Microchip's migration guide, the configuration bits are different (LVP and IESO behaviour), the ADC channel mapping is rearranged, and the comparator output routing changed. Boards designed for PIC18LF4550 will accept PIC18F45K50 silicon directly in the same 44-pin TQFP /PT footprint, but boards for non-LF PIC18F4550 must verify VDD is at least 2.3 V (K50 minimum).
Place the 4-layer stack-up with a continuous ground plane under the TQFP-44 footprint. Route the USB D+ and D- differential pair with 90 ohm differential impedance, matched lengths within 150 mil, and a series 27-33 ohm ferrite bead at the connector side for EMI. Keep RC6/RC7 traces short if they are used as the UART to a legacy device, and place a 4.7 kohm pull-up on MCLR (pin 1) for proper reset behaviour.
When using the internal 48 MHz oscillator for USB, enable Active Clock Tuning (ACT) via the ACTCON register so the device trims its RC oscillator against USB host frame timing. This eliminates the need for an external crystal on most designs but requires a one-time USB enumeration at boot. If crystal accuracy is required (e.g. for a CDC bridge that runs with the USB unplugged), add a 20 MHz fundamental-mode crystal between OSC1 (pin 13) and OSC2 (pin 14) with 15-22 pF load capacitors to ground.
Compliance Information
RoHS compliant per Microchip product page. /PT suffix indicates Pb-free matte tin plating. Industrial -40 C to +85 C grade (I suffix). Not AEC-Q100 qualified - choose PIC18F46K50-E/Pt or similar -E grade parts for automotive.
