PIC18LF4450T-I/ML - 16KB Flash USB MCU 48MHz QFN-44 | Microchip
MPN: PIC18LF4450T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.1 | $4.10 |
| 10 | $3.78 | $37.80 |
| 100 | $3.25 | $325.00 |
| 500 | $2.85 | $1,425.00 |
| 1,000 | $2.55 | $2,550.00 |
PIC18LF4450T-I/ML Overview
A USB microcontroller is a specialized MCU that integrates a USB transceiver and serial interface engine (SIE) directly on-chip, eliminating the need for an external USB PHY. It belongs to the broader category of embedded controllers within the microcontroller -> 8-bit MCU -> PIC18 family -> USB-capable MCU hierarchy. The 'LF' prefix denotes a low-voltage variant optimized for battery-powered and low-power applications using Microchip's nanoWatt technology, while the 'F' architecture provides enhanced Flash with self-programming capability.
Key features include 34 digital I/O pins, 13-channel 10-bit ADC, two analog comparators, two CCP modules, one enhanced USART, MSSP (SPI/I2C), and hardware multiply. The device supports ICSP (In-Circuit Serial Programming) and ICD (In-Circuit Debugger) for development workflows. nanoWatt power management provides multiple idle and sleep modes with current consumption under 1 microamp in sleep, suitable for USB bus-powered and battery applications. The integrated USB 2.0 Full-Speed transceiver supports low-speed (1.5 Mbps) and full-speed (12 Mbps) operation with on-chip SIE handling protocol, leaving the CPU free for application code.
Typical applications include USB peripherals (HID-class devices, CDC virtual COM ports, mass storage), industrial control interfaces with USB diagnostics ports, USB-to-UART bridges, embedded data loggers with USB download, and battery-powered handheld instruments. The wide 2.0-5.5V supply range also supports both 3.3V and 5V system designs without level translation.
When designing with this device, ensure the USB D+/D- traces are routed as a 90-ohm differential pair with characteristic impedance controlled to USB 2.0 specification. The internal 3.3V USB voltage regulator requires adequate decoupling (220 nF plus 100 uF bulk) per the datasheet reference design. The exposed thermal pad (EP) must be soldered to a ground plane for electrical and thermal performance.
This page synthesizes distributor pricing, drop-in alternatives from the Microchip PIC18 family, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18LF4450T-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 PIC18LF4450T-I/ML (same form factor and footprint) — differing in Core Architecture, Operating Temperature, Package, I/O Pins, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4450-I/ML
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F4550-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4550-I/ML
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F4550T-I/ML
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →PIC18F46J50-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4450T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 RISC |
| Program Memory Type | Enhanced Flash |
| Program Memory Size | 16 KB |
| RAM Size | 768 bytes |
| EEPROM Size | 0 bytes (not present on this family) |
| Maximum CPU Speed | 48 MHz (12 MIPS) |
| Supply Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 34 |
| USB Interface | USB 2.0 Full-Speed (12 Mbps) and Low-Speed (1.5 Mbps), integrated transceiver |
| ADC | 10-bit, up to 13 channels |
| Analog Comparators | 2 |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Communication Peripherals | 1x EUSART, 1x MSSP (SPI / I2C) |
| Timers | 4 (Timer0/1/2/3) |
| Package | QFN-44 (8 x 8 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (Industrial, I-suffix) |
| Power-Saving Modes | nanoWatt (multiple idle/sleep modes) |
| Programming/Debug | ICSP and ICD |
| RoHS Status | Compliant (Pb-free) |
PIC18LF4450T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC VREF minus |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF plus |
| Pin 5 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 6 | RA5/AN4 — PORTA bit 5 / Analog input 4 |
| Pin 7 | VSS — Ground reference |
| Pin 8 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 9 | OSC2/CLKO — Crystal oscillator output / clock output |
| Pin 10 | RC0/T1OSO — PORTC bit 0 / Timer1 oscillator output |
| Pin 11 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 13 | VUSB — Internal USB 3.3V regulator output (bypass to VSS with 220nF + 100uF) |
| Pin 14 | VBUS — USB VBUS sense input (5V) |
| Pin 15 | RC4/D-/VM — PORTC bit 4 / USB D- data line |
| Pin 16 | RC5/D+/VP — PORTC bit 5 / USB D+ data line |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / EUSART TX / clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / EUSART RX / data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (2.0-5.5V) |
| Pin 21 | RB0/AN12 — PORTB bit 0 / Analog input 12 |
| Pin 22 | RB1/AN10 — PORTB bit 1 / Analog input 10 |
| Pin 23 | RB2/AN8 — PORTB bit 2 / Analog input 8 |
| Pin 24 | RB3/AN9 — PORTB bit 3 / Analog input 9 / PGM |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply (2.0-5.5V) |
| Pin 31 | RD0 — PORTD bit 0 |
| Pin 32 | RD1 — PORTD bit 1 |
| Pin 33 | RD2 — PORTD bit 2 |
| Pin 34 | RD3 — PORTD bit 3 |
| Pin 35 | RC3 — PORTC bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply (2.0-5.5V) |
| Pin 42 | RE0 — PORTE bit 0 |
| Pin 43 | RE1 — PORTE bit 1 |
| Pin 44 | RE2 — PORTE bit 2 |
Typical Applications
PIC18LF4450T-I/ML is suitable for 6 applications: USB HID Peripheral (Keyboard / Mouse / Gamepad), USB-to-UART / CDC Virtual COM Port Bridge, Industrial USB Diagnostic / Programming Port, Battery-Powered USB Data Logger, Embedded USB Mass Storage / MSD Reader, USB-Connected Sensor Hub (IoT Edge Node).
USB HID Peripheral (Keyboard / Mouse / Gamepad)
The PIC18LF4450T-I/ML is purpose-built for USB HID-class peripherals thanks to its integrated USB 2.0 Full-Speed transceiver and 12 MIPS CPU throughput. With 16 KB Flash it fits HID firmware plus a USB bootloader, while 768 bytes of RAM accommodate HID report buffers and key-matrix state. The wide 2.0-5.5 V supply lets the device run from USB VBUS (5 V) or a Li-ion cell (3.7 V nominal) without level translation. Placed between the USB connector and a key-matrix scan circuit, it handles protocol framing, descriptor requests, and HID report generation entirely in firmware; no external PHY required. Compared to adding an FTDI bridge plus a separate MCU, the integrated approach cuts BOM cost and PCB area while freeing GPIOs for scanning.
Recommended
USB-to-UART / CDC Virtual COM Port Bridge
The PIC18LF4450T-I/ML is widely deployed as a CDC-class USB-to-serial bridge, replacing legacy RS-232 with a virtual COM port over USB 2.0 Full-Speed. Its integrated SIE offloads USB framing and bulk-transfer handling from the CPU, while the EUSART peripheral drives an external RS-232/RS-485 transceiver at up to 115.2 kbps. The 16 KB Flash easily accommodates Microchip's CDC stack, command-line interpreter, and bootloader. Operating from 2.0-5.5 V lets the same design serve 3.3 V MCUs or 5 V legacy UART peripherals. Compared to a dedicated bridge IC like FT232, this approach is firmware-customizable for vendor-specific requests and lower BOM cost.
Recommended
Industrial USB Diagnostic / Programming Port
Industrial controllers, sensors, and motor drives use the PIC18LF4450T-I/ML to add a USB service-port for field diagnostics, firmware updates, and event-log download. The industrial -40 to +85 C temperature range and the wide 2.0-5.5 V supply make it tolerant of factory-floor power rails, while the integrated USB transceiver eliminates a fragile external PHY that would otherwise need TVS protection. The ICSP interface shares pins with the USB data lines, so a single micro-USB connector serves both production programming and runtime diagnostics. Compared to larger ARM Cortex-M USB parts, the PIC18LF4450T-I/ML is a low-cost, low-power alternative when only modest code space and modest GPIO count are needed.
Recommended
Battery-Powered USB Data Logger
The PIC18LF4450T-I/ML suits battery-powered USB data loggers where idle power is critical. Its nanoWatt technology and the 'LF' low-voltage core allow sleep currents under 1 microamp while still waking on USB attach events, conserving battery between user sessions. The 16 KB Flash fits a small file system and FAT12/16 stack for removable-storage emulation, and the 768-byte RAM accommodates sector buffers. Operating from 2.0 V lets a single Li-ion or 2x AA cell power the device directly. Compared to higher-speed Cortex-M USB parts, the PIC18 LF family delivers lower sleep current and a simpler USB stack footprint.
Recommended
Embedded USB Mass Storage / MSD Reader
The PIC18LF4450T-I/ML can implement a USB Mass Storage Device (MSD) class reader when paired with an external SPI Flash or SD card socket, exposing the storage as a removable USB drive to the host PC. Its integrated USB 2.0 Full-Speed SIE handles bulk-only transport protocol and SCSI command blocks, while the MSSP peripheral drives SPI Flash at up to 10 MHz. The 16 KB Flash holds the USB MSD stack plus FAT12/16 file system, and the wide 2.0-5.5 V supply accepts USB VBUS directly. Compared to a dedicated USB Flash card reader IC, the firmware-programmable MCU allows custom vendor commands and on-device status LEDs.
Recommended
USB-Connected Sensor Hub (IoT Edge Node)
IoT edge nodes that stream sensor data over USB benefit from the PIC18LF4450T-I/ML's 13-channel 10-bit ADC, I2C/SPI master interfaces, and integrated USB 2.0 Full-Speed link. The device aggregates temperature, humidity, and motion-sensor data, packages it into HID or vendor-class reports, and streams it to a host PC or embedded gateway. Operating from 2.0-5.5 V supports USB bus-powered designs or battery operation; nanoWatt sleep modes save energy between host polls. Compared to a Cortex-M0+ USB solution, this PIC18 LF variant is lower cost and uses a mature Microchip USB stack with abundant reference designs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4450T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4450-I/ML | PIC18F4550-I/ML | PIC18LF4550-I/ML | PIC18F4550T-I/ML | PIC18F46J50-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | QFN-44 (8x8 mm) | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same | QFN-44 (8x8 mm) - same |
| Program Memory (Flash) | 16 KB | 16 KB | 32 KB | 32 KB | 32 KB | 64 KB |
| RAM | 768 bytes | 768 bytes | 2048 bytes | 2048 bytes | 2048 bytes | 3800 bytes |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 3.6 V |
| Max CPU Speed | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS |
| I/O Pins | 34 | 34 | 35 | 35 | 35 | 34 |
| USB Interface | USB 2.0 Full/Low Speed integrated | USB 2.0 Full/Low Speed integrated | USB 2.0 Full/Low Speed integrated | USB 2.0 Full/Low Speed integrated | USB 2.0 Full/Low Speed integrated | USB 2.0 Full/Low Speed integrated |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Key Differentiators
- Lowest minimum supply voltage in PIC18 USB family (vs PIC18F4550-I/ML)
- nanoWatt power-saving technology (vs PIC18F4550-I/ML)
- Smaller Flash footprint for cost-sensitive HID designs (vs PIC18F4550T-I/ML)
Design Notes
Route the USB D+ and D- lines (RC4/D-, RC5/D+) as a 90-ohm differential pair with characteristic impedance of 90 ohms +/- 10%, length-matched to within 2 mm. Place the 220 nF decoupling capacitor on VUSB as close to the pin as possible, and add a 100 uF bulk capacitor on the same node to support USB inrush current. The exposed thermal pad (EP) under the QFN-44 must be soldered to a contiguous ground plane for both thermal dissipation and low-impedance ground return. Keep digital switching traces away from the USB differential pair to minimize radiated EMI.
Estimated: With VBUS at 5 V and MCU running at 48 MHz from a 3.3 V LDO, total active current is approximately 15-25 mA, and sleep current drops below 1 microamp in nanoWatt Sleep. If the device is bus-powered from USB VBUS, ensure the upstream port can supply at least 100 mA (USB high-power device class) and add a 10 uF bulk capacitor near the VBUS pin to handle hot-plug inrush. For self-powered designs, the VBUS pin must still be tied to the USB connector to detect attach/detach events.
Do not omit the VUSB decoupling network (220 nF plus 100 uF), or the internal 3.3 V USB regulator will oscillate and USB enumeration will fail. Do not load the internal 3.3 V regulator with external circuitry; it is sized only for the internal USB transceiver. When designing for USB-IF compliance, add a 1.5 kohm pull-up on D+ for full-speed enumeration or on D- for low-speed enumeration - this selection must match the device descriptor reported in firmware.
Place a ferrite bead or common-mode choke in series with VBUS if the design may be exposed to ESD or conducted noise from the USB host. Add TVS diodes (such as USBLC6-2SC6) on D+/D- for ESD protection exceeding 8 kV contact discharge. The crystal oscillator traces (OSC1/OSC2) should be short and guarded by a ground ring; keep the crystal within 5 mm of the MCU and avoid routing noisy signals adjacent to the oscillator traces.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade -40C to +85C (I-suffix). Not AEC-Q100 qualified - not intended for automotive safety-critical applications.
