PIC18LF4450-I/ML - 48MHz 8-bit USB MCU, 16KB Flash, 44-QFN | Microchip
MPN: PIC18LF4450-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.4 | $6.40 |
| 10 | $5.78 | $57.80 |
| 100 | $5.12 | $512.00 |
| 500 | $4.62 | $2,310.00 |
| 1,000 | $4.1 | $4,100.00 |
PIC18LF4450-I/ML Overview
An 8-bit microcontroller (MCU) is a self-contained compute subsystem on a single silicon die, integrating a CPU core, non-volatile program memory (Flash), volatile data memory (SRAM), digital peripherals (timers, UART, I2C, SPI, USB) and general-purpose I/O. The PIC18 family is the high-performance tier of Microchip's 8-bit MCU line, sitting above PIC10/12/16 in peripheral richness and instruction throughput. The LF sub-family trades absolute speed headroom for wider operating-voltage range and nanoWatt sleep modes, making it a fit for battery- and bus-powered edge devices.
Key features include 10-bit ADC with up to 13 input channels, three counter/timers, a Capture/Compare/PWM module, an Enhanced USART (EUSART, LIN-capable), Master I2C and SPI (up to 10 Mbit/s), the Full-Speed USB 2.0 transceiver with on-chip SIE, and Microchip's nanoWatt power-management block with Idle, Sleep and deep-sleep modes. The 44-QFN (ML) package exposes 34 general-purpose I/O lines plus dedicated USB D+/D- pads, VUSB and the internal 3.3V USB regulator.
Architecturally the PIC18LF4450 implements an enhanced Harvard RISC core with 16-bit instructions, a hardware multiplier (8x8 single-cycle) and a 31-level deep stack. The integrated USB SIE handles packet framing, CRC and the physical-layer signaling so the CPU is freed from bit-banging, dramatically lowering firmware complexity for HID, CDC and vendor-class USB applications.
Typical applications include USB HID peripherals (keyboards, mice, custom joysticks), USB-to-UART bridges, low-power sensor nodes with USB charging, industrial data loggers, LIN slave nodes in automotive body controllers, and educational/development boards. The wide 2.0-5.5 V range lets the device run directly from a single Li-ion cell, two AA cells, or a 3.3 V regulated rail.
When designing with this part, observe the PCB layout rules in Microchip AN233 (USB PCB layout) - the D+/D- traces must be 90 ohm differential, matched-length, and the VUSB decoupling capacitor must be within 5 mm of the VUSB pin. For self-powered designs, the internal 3.3 V USB regulator can be disabled via CONFIG and an external rail supplied to the VUSB pin.
This page synthesizes current distributor pricing, drop-in same-package alternatives, and practical layout notes that go beyond the datasheet to speed USB-MCU bring-up.
Drop-in alternatives for PIC18LF4450-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 PIC18LF4450-I/ML (same form factor and footprint) — differing in Operating Temperature, Package, ADC, I/O Pins, Communication Peripherals.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4550-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4450-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4455-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2550-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F46K40-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.55 / Unit
View Datasheet →PIC18LF4450-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data Memory (SRAM) | 768 B |
| EEPROM | 256 B |
| Maximum CPU Clock | 48 MHz (12 MIPS) |
| Operating Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 34 |
| ADC | 10-bit, up to 13 channels |
| USB | USB 2.0 Full-Speed (12 Mbit/s) with on-chip SIE |
| Timers | 3 (Timer0/1/2) + 1 CCP |
| Communication Peripherals | EUSART (LIN-capable), I2C (Master), SPI (up to 10 Mbit/s) |
| Package | 44-pin QFN (ML) 8x8 mm with exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (Industrial, "I") |
| Power-Saving Modes | nanoWatt: Idle, Sleep, Deep Sleep, Run |
PIC18LF4450-I/ML Pin Configuration
| Pin 1 | RC2/CCP1 — I/O port C bit 2 / Capture Compare PWM 1 |
| Pin 2 | VSS — Ground reference |
| Pin 3 | RA0/AN0 — I/O port A bit 0 / analog input 0 |
| Pin 4 | RA1/AN1 — I/O port A bit 1 / analog input 1 |
| Pin 5 | RA2/AN2 — I/O port A bit 2 / analog input 2 |
| Pin 6 | RA3/AN3 — I/O port A bit 3 / analog input 3 |
| Pin 7 | RA4/T0CKI — I/O port A bit 4 / Timer0 clock input |
| Pin 8 | RA5/AN4 — I/O port A bit 5 / analog input 4 |
| Pin 9 | RE0 — I/O port E bit 0 |
| Pin 10 | RE1 — I/O port E bit 1 |
| Pin 11 | RE2 — I/O port E bit 2 |
| Pin 12 | VDD — Positive supply (2.0-5.5 V) |
| Pin 13 | OSC1/CLKI — Crystal input / external clock |
| Pin 14 | OSC2/CLKO — Crystal output / clock out |
| Pin 15 | VSS — Ground reference |
| Pin 16 | RC0/T1OSO — I/O port C bit 0 / Timer1 oscillator out |
| Pin 17 | RC1/T1OSI — I/O port C bit 1 / Timer1 oscillator in |
| Pin 18 | VUSB — Internal 3.3 V USB regulator output (decouple with 220 nF) |
| Pin 19 | D- — USB data minus (90 ohm differential with D+) |
| Pin 20 | D+ — USB data plus (90 ohm differential with D-) |
| Pin 21 | RD0 — I/O port D bit 0 |
| Pin 22 | RD1 — I/O port D bit 1 |
| Pin 23 | RD2 — I/O port D bit 2 |
| Pin 24 | RD3 — I/O port D bit 3 |
| Pin 25 | RD4 — I/O port D bit 4 |
| Pin 26 | RD5 — I/O port D bit 5 |
| Pin 27 | RD6 — I/O port D bit 6 |
| Pin 28 | RD7 — I/O port D bit 7 |
| Pin 29 | VSS — Ground reference |
| Pin 30 | RC6/TX/CK — I/O port C bit 6 / EUSART TX / clock |
| Pin 31 | RC7/RX/DT — I/O port C bit 7 / EUSART RX / data |
| Pin 32 | RB0/AN12 — I/O port B bit 0 / analog input 12 |
| Pin 33 | RB1/AN10 — I/O port B bit 1 / analog input 10 |
| Pin 34 | RB2/AN8 — I/O port B bit 2 / analog input 8 |
| Pin 35 | RB3/AN9 — I/O port B bit 3 / analog input 9 |
| Pin 36 | RB4 — I/O port B bit 4 |
| Pin 37 | RB5 — I/O port B bit 5 |
| Pin 38 | RB6/PGC — I/O port B bit 6 / ICSP clock |
| Pin 39 | RB7/PGD — I/O port B bit 7 / ICSP data |
| Pin 40 | VDD — Positive supply (2.0-5.5 V) |
| Pin 41 | RC4/SDA — I/O port C bit 4 / I2C data |
| Pin 42 | RC5/SCL — I/O port C bit 5 / I2C clock |
| Pin 43 | RC3 — I/O port C bit 3 |
| Pin 44 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 45 | EP — Exposed thermal pad - tie to VSS (ground) |
Typical Applications
PIC18LF4450-I/ML is suitable for 6 applications: USB HID Peripherals (Keyboard / Mouse / Custom Joystick), USB-to-UART / USB-to-SPI Bridge, Battery-Powered USB Sensor Node, Industrial Data Logger with USB Upload, LIN Slave / Body-Controller Node (Non-AEC-Q100), Educational / Hobbyist USB Development Board.
USB HID Peripherals (Keyboard / Mouse / Custom Joystick)
The PIC18LF4450's integrated USB 2.0 Full-Speed SIE and 16 KB Flash make it a strong fit for low-cost USB HID devices. The on-chip SIE handles NRZI encoding, bit stuffing and CRC so the CPU is free to scan a keyboard matrix, debounce buttons, or sample an analog joystick - tasks that fit comfortably in 16 KB of XC8-compiled firmware. Its 10-bit ADC reads the joystick potentiometers directly, while the 48 MHz / 12 MIPS core delivers ample headroom for HID class descriptors and custom report formats. The wide 2.0-5.5 V supply lets the device draw power directly from the USB VBUS rail through a 3.3 V LDO, eliminating the need for a separate power IC in this application.
Recommended
USB-to-UART / USB-to-SPI Bridge
In USB-to-UART bridge designs the PIC18LF4450's EUSART, SPI (up to 10 Mbit/s) and USB SIE replace the classic FTDI bridge topology at a lower BOM cost. The 48 MHz core can sustain 921600 baud on the EUSART while servicing USB CDC interrupt transfers without data loss. The 2.0-5.5 V supply lets the bridge interface directly to 3.3 V MCUs without level shifters, and the 256-byte EEPROM stores USB VID/PID pairs and user configuration that can be re-flashed in-circuit. Use the internal 3.3 V USB regulator to power the bus-pulled D+/D- lines and free an external LDO slot.
Recommended
Battery-Powered USB Sensor Node
The PIC18LF4450-I/ML's 2.0-5.5 V range and nanoWatt power management are tuned for Li-ion- or 2x AA-powered sensor nodes that recharge or sync over USB. Sleep current drops into the single-digit-microamp range with the USB SIE and ADC disabled, so a 2000 mAh Li-ion cell can run multi-year duty cycles. The 10-bit ADC reads thermistor, photodiode or gas-sensor outputs without a separate analog front-end, while the I2C bus chains a digital accelerometer or humidity sensor. When the USB cable is plugged in, the part auto-detects VBUS, enumerates, and streams cached data to the host - a complete edge-node on one die.
Recommended
Industrial Data Logger with USB Upload
Industrial data loggers benefit from the PIC18LF4450's 256-byte EEPROM (for configuration and RTC trim), 768-byte SRAM ring buffer, and 16 KB Flash for a small FAT12/16 file-system image plus a UART/Modbus logger stack. The EUSART (LIN-capable) interfaces directly to RS-485 transceivers for field-bus polling, while the on-chip 10-bit ADC samples 4-20 mA loop signals through a burden resistor. USB Full-Speed is used only for data export, so the part spends 99% of its time at 31 kHz internal oscillator to minimize power. The 44-QFN exposed pad dissipates heat effectively in the -40 C to +85 C industrial range.
Recommended
LIN Slave / Body-Controller Node (Non-AEC-Q100)
While the PIC18LF4450 is not AEC-Q100 qualified, its EUSART with LIN protocol support, 2.0-5.5 V supply range, and -40 C to +85 C industrial rating suit non-safety automotive accessories: HVAC control, ambient lighting, or seat-position memory. The 10-bit ADC reads thermistor inputs for cabin-temperature regulation; PWM drives small motors or LED strings; LIN transceivers connect directly to the EUSART with no external protocol controller. The 16 KB Flash accommodates a LIN state-machine plus diagnostic stack in XC8. For safety-critical or AEC-Q100 applications migrate to PIC18F46K40 or PIC18F26K83 family.
Recommended
Educational / Hobbyist USB Development Board
The PIC18LF4450-I/ML is a staple of university curricula and open-source USB development kits (PINGUINO, PIC18F4550 Open Source USB Framework) because it integrates USB without external PHY crystals. The 44-QFN is breadboard-friendly with carrier PCBs that expose every I/O pin to 0.1-inch headers, while the 2.0-5.5 V supply lets students power the board from a bench supply, USB port, or 9 V battery with a linear regulator. 16 KB Flash is enough to demonstrate HID, CDC, MIDI, and custom-bulk class examples; the 48 MHz core enables real-time signal processing demos (FFT, DSP filter). MPLAB X IDE, XC8, and Microchip Code Configurator are all free and well-documented.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4450-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4550-I/ML | PIC18F4450-I/ML | PIC18F4455-I/ML | PIC18F46K40-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (ML) 8x8 mm | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same |
| Flash Memory | 16 KB | 32 KB | 32 KB | 24 KB | 64 KB |
| RAM | 768 B | 2 KB | 2 KB | 2 KB | 4 KB |
| Operating Voltage | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 1.8 V to 3.6 V |
| USB Support | FS USB 2.0 + internal 3.3V reg | FS USB 2.0 + internal 3.3V reg | FS USB 2.0 + internal 3.3V reg | FS USB 2.0 + internal 3.3V reg | No native USB (USB via external PHY) |
| Max Clock Speed | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 48 MHz (12 MIPS) | 64 MHz (16 MIPS) |
| ADC Resolution | 10-bit (13 channels) | 10-bit (13 channels) | 10-bit (13 channels) | 10-bit (13 channels) | 10-bit (35 channels, with DAC/CTMU) |
| AEC-Q100 Qualified | No (industrial -40 to +85 C) | No | No | No | Yes (Q variants available) |
| Indicative Price (qty 1) | USD 6.40 | USD 7.20 | USD 6.95 | USD 6.50 | USD 3.90 |
Key Differentiators
- Widest operating-voltage range in the PIC18F4450 USB family (vs PIC18F4550-I/ML)
- nanoWatt low-power modes for USB-attach battery devices (vs PIC18F46K40-I/ML)
- Lower entry price for cost-sensitive HID/CAN applications (vs PIC18F4455-I/ML)
Design Notes
USB D+ and D- traces must be routed as a 90-ohm differential pair, matched within 0.5 mm in length, with continuous ground reference plane beneath. Keep the 220 nF VUSB decoupling capacitor within 5 mm of the VUSB pin (pin 18) and the crystal within 5 mm of OSC1/OSC2 with short traces surrounded by a grounded guard ring. Reference: Microchip AN233 'USB PCB Layout Guidelines'.
Estimated: average active current at 48 MHz, 5.5 V is ~15 mA with USB idle, ~22 mA with USB active. In sleep mode (CPU off, peripherals off) Iq drops to ~0.1 uA. For self-powered designs disable the internal 3.3 V USB regulator by clearing the VREGEN CONFIG bit and supplying 3.3 V to the VUSB pin from an external rail. For bus-powered designs the internal regulator auto-powers from VBUS.
Do not omit the MCLR pull-up (10 k to VDD) - the device will randomly reset. Do not tie VUSB to VDD - the internal regulator requires a dedicated decoupling cap to GND. Ensure the exposed pad (EP, pin 45) is soldered to a continuous ground pour, both for thermal dissipation and for stable USB signaling. Do not exceed 10 MHz on SCK without checking the SPI electrical spec for capacitive load.
The 10-bit ADC is specified at 30 ksps; sampling a 4 kHz signal requires RC input impedance below 10 kohm for full accuracy. Add a 100 nF ceramic bypass directly on each AVDD-style analog pin if used, and route analog traces away from USB differential pair. For high-impedance sensor inputs use the on-chip CTMU or add an external op-amp buffer rather than relying on the ADC's internal holding capacitor.
Compliance Information
ML package suffix denotes lead-free matte-tin finish. Not AEC-Q100 - for automotive applications use PIC18F46K40 Q variants or PIC18F26K83 in larger packages.