PIC18F4450T-I/PT - 48MHz 8-bit USB MCU 16KB Flash | Microchip
MPN: PIC18F4450T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.45 | $64.50 |
| 100 | $5.62 | $562.00 |
| 500 | $5.05 | $2,525.00 |
| 1,000 | $4.58 | $4,580.00 |
| 3,000 | $4.1 | $12,300.00 |
PIC18F4450T-I/PT Overview
What is a PIC18F microcontroller? The PIC18F is Microchip Technology's high-performance 8-bit PIC microcontroller family, positioned above the PIC16F series in performance and below the PIC24/dsPIC 16-bit families. PIC18F devices follow the standard PIC taxonomy (microcontroller -> embedded controller -> semiconductor) and integrate flash memory, SRAM, EEPROM, A/D converters, and communication peripherals on a single CMOS die. The 4450 specifically targets USB-enabled human-interface and embedded-host-bridge designs where a full-speed (12 Mbps) USB device port replaces an external transceiver PHY.
Key features include an integrated Full-Speed USB 2.0 device controller with on-chip transceiver, 10-bit A/D converter with up to 13 input channels, two 8-bit and three 16-bit timers, two capture/compare/PWM modules, an Enhanced USART, MSSP (SPI/I2C), nanoWatt power management, and a 13-channel 10-bit ADC. The 44-pin TQFP package exposes 34 general-purpose I/O pins. The 5V operating range (4.2V to 5.5V) makes the part suitable for industrial and legacy 5V systems. Program memory is in-circuit serial programmable (ICSP) via two pins, supporting field updates without removing the part from the board.
Architecture-wise, the PIC18F4450 employs a Harvard RISC core with separate program and data buses, a hardware multiplier, and an 8-level deep hardware stack, allowing deterministic interrupt latency typical of PIC microcontrollers. The nanoWatt technology includes multiple idle and sleep modes that drop core current to microampere levels, with peripheral activity managed by independent clock gating. The USB SIE (Serial Interface Engine) handles the USB protocol in hardware, offloading packet framing, CRC, and endpoint management from the CPU.
Typical applications include USB HID peripherals (keyboards, mice, custom input devices), USB-to-UART bridges, low-cost data loggers with analog sensor inputs, industrial control front-ends with Modbus RTU via RS-485, and consumer electronics with touch or capacitive sensing. The combination of USB, ADC, and 5V tolerance makes it a drop-in upgrade for legacy 5V systems adding modern connectivity.
When designing, ensure the VUSB pin is decoupled with a 220nF capacitor as recommended in the Microchip datasheet and that the D+/D- traces are routed as a 90-ohm differential pair. Firmware must initialize the USB PLL and oscillator configuration registers before the SIE will enumerate; review Microchip's USB framework documentation for ready-made HID, CDC, and vendor-class stacks.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that complement the Microchip datasheet rather than simply restating it.
Drop-in alternatives for PIC18F4450T-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 PIC18F4450T-I/PT (same form factor and footprint) — differing in Timers, Operating Temperature, ADC, Package, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4450-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4550-I/PT
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC18F4455-I/PT
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC18F4458-I/PT
✅ Drop-In✓ In Stock
$5.79 / Unit
View Datasheet →PIC18F46J50-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4450T-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Series | PIC18F |
| CPU Speed | 48 MHz (12 MIPS) |
| Program Memory | 16 KB (8K x 16) Flash |
| RAM | 768 bytes |
| Supply Voltage | 4.2 V to 5.5 V |
| I/O Pins | 34 |
| USB | Full-Speed USB 2.0 Device with on-chip transceiver |
| ADC | 10-bit, up to 13 channels |
| Timers | 2 x 8-bit + 3 x 16-bit |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Communication | EUSART, MSSP (SPI/I2C) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 |
| RoHS Status | Compliant |
| Programmable | In-Circuit Serial Programming (ICSP) |
| Power-Saving Modes | nanoWatt technology (Idle, Sleep, Low-Power modes) |
PIC18F4450T-I/PT Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / ICSP programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS/HLVDIN — PORTA bit 5 / analog input 4 / SPI slave select / HLVD input |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / read control / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input 7 |
| Pin 11 | VDD — Positive supply voltage (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock / PORTA bit 7 |
| Pin 14 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / PORTA bit 6 |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| Pin 18 | RC3 — PORTC bit 3 |
| Pin 19 | RC4/D-/VMO — PORTC bit 4 / USB D- / USB VMO monitor output |
| Pin 20 | RC5/D+/VPO — PORTC bit 5 / USB D+ / USB VPO monitor output |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / EUSART TX / EUSART synchronous clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / EUSART RX / EUSART synchronous data |
| Pin 23 | RB0/AN12/INT0 — PORTB bit 0 / analog input 12 / external interrupt 0 |
| Pin 24 | RB1/AN10/INT1 — PORTB bit 1 / analog input 10 / external interrupt 1 |
| Pin 25 | RB2/AN8/INT2 — PORTB bit 2 / analog input 8 / external interrupt 2 |
| Pin 26 | RB3/AN9/CCP2 — PORTB bit 3 / analog input 9 / CCP2 output |
| Pin 27 | RB4/AN11/KBI0 — PORTB bit 4 / analog input 11 / interrupt-on-change bit 0 |
| Pin 28 | RB5/KBI1/PGM — PORTB bit 5 / interrupt-on-change bit 1 / ICSP PGM |
| Pin 29 | RB6/KBI2/PGC — PORTB bit 6 / interrupt-on-change bit 2 / ICSP clock |
| Pin 30 | RB7/KBI3/PGD — PORTB bit 7 / interrupt-on-change bit 3 / ICSP data |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (5V) |
| Pin 33 | RD0 — PORTD bit 0 |
| Pin 34 | RD1 — PORTD bit 1 |
| Pin 35 | RD2 — PORTD bit 2 |
| Pin 36 | RD3 — PORTD bit 3 |
| Pin 37 | RD4 — PORTD bit 4 |
| Pin 38 | RD5 — PORTD bit 5 |
| Pin 39 | RD6 — PORTD bit 6 |
| Pin 40 | RD7 — PORTD bit 7 |
| Pin 41 | VUSB — USB 3.3V regulator output (decouple with 220 nF) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | AVDD — Analog supply voltage (tie to VDD) |
Typical Applications
PIC18F4450T-I/PT is suitable for 7 applications: USB HID Peripherals (Keyboard/Mouse/Custom Input), USB-to-UART / USB-to-SPI Bridge, Industrial Sensor Data Logger, USB Consumer Electronics (Toy / Wearable Dongle), Educational / Hobby USB Development Board, USB-Connected Medical Accessory (Non-Critical), USB-Controlled Lighting / Stage Effects.
USB HID Peripherals (Keyboard/Mouse/Custom Input)
The PIC18F4450T-I/PT is purpose-built for USB Human Interface Device peripherals thanks to its integrated Full-Speed USB 2.0 device SIE and on-chip transceiver, which remove the need for an external PHY and let BOM cost stay low. With 16KB flash and 768B RAM it fits the Microchip USB HID stack plus custom HID report descriptors for keyboards, mice, game controllers, or custom input panels. The 48MHz/12 MIPS core is sufficient for HID polling at 125 us intervals and debouncing without missing frames. The 5V tolerance makes the part a natural fit for legacy 5V keyboards or industrial input panels that need modern USB connectivity while preserving noise margins on long cable runs.
Recommended
USB-to-UART / USB-to-SPI Bridge
A common industrial use case for the PIC18F4450T-I/PT is a CDC-based USB-to-UART bridge that turns a legacy RS-232 sensor or microcontroller into a USB device with no host-side driver changes. The integrated EUSART supports baud rates up to the MCU limit, while the MSSP peripheral can simultaneously run I2C or SPI for a USB-to-I2C/SPI gateway. The 10-bit ADC with 13 input channels enables a USB data-acquisition frontend that streams analog sensor readings at high speed. The 5V I/O tolerance simplifies level shifting to industrial 24V-isolated front-ends; the 44-TQFP footprint exposes 34 GPIO pins for status LEDs and flow-control handshakes typical of bridge designs.
Recommended
Industrial Sensor Data Logger
The PIC18F4450T-I/PT serves as the controller in low-cost industrial data loggers that combine analog sensing with USB data offload. The 10-bit ADC with 13 input channels can digitize thermocouple-amplified or 4-20mA-conditioned signals, while the 16KB flash holds a file system and timestamp table for weeks of unattended logging. The nanoWatt sleep current under 1 uA lets a battery-powered logger wake on a timer interrupt, take a sample, and return to sleep between events. The USB SIE enables fast offload of the captured log to a PC host at Full Speed when the field technician plugs in, eliminating the need for a removable SD card slot in hazardous locations.
Recommended
USB Consumer Electronics (Toy / Wearable Dongle)
Consumer USB dongles such as wireless audio receivers, configuration tools, and firmware update sticks leverage the PIC18F4450T-I/PT's compact 44-TQFP footprint and integrated USB transceiver. The 48MHz core can drive SPI-based wireless transceivers or LED matrices while simultaneously maintaining a USB enumeration as a CDC or vendor-class device. The ICSP programming interface allows factory firmware updates over the same USB pins used in production, simplifying the manufacturing test flow. The industrial -40C to +85C temperature rating ensures the part survives consumer-environment thermal stress, and the wide 4.2V to 5.5V supply range accepts USB bus power directly without additional regulation.
Recommended
Educational / Hobby USB Development Board
The PIC18F4450T-I/PT is widely used in hobbyist and educational USB development kits because it combines USB, ADC, PWM, and ICSP programming in a single easy-to-solder TQFP package. The Microchip MPLAB X IDE and XC8 compiler provide a free toolchain, and the open-source USB stack (MLA / MCC USB) supports CDC, HID, and vendor-class examples ready for modification. The 5V tolerance simplifies lab-bench wiring with breadboard-friendly 5V sensors, while the 34 GPIO pins are sufficient for student projects involving LEDs, sensors, and character LCDs. For more capable students, the firmware can be upgraded to PIC18F4550-I/PT with no hardware change.
Recommended
USB-Connected Medical Accessory (Non-Critical)
In non-critical medical accessories such as fitness wearables, breathing trainers, or USB-connected therapy reminder dongles, the PIC18F4450T-I/PT delivers the USB connectivity and ADC sampling required for sensor front-ends. The 10-bit ADC captures pulse, respiration, or temperature analog signals, and the USB device interface streams these readings to a host PC or tablet application. The industrial temperature rating covers the storage and operating ranges typical of consumer medical accessories, while the 5V tolerance accepts battery-charger-derived rails. For designs that must ship outside the consumer space, the automotive and medical-specific PIC18F variants remain in the same 44-TQFP family for migration paths.
Recommended
USB-Controlled Lighting / Stage Effects
Stage lighting fixtures and DJ controllers often use the PIC18F4450T-I/PT as a USB-connected DMX or PWM controller because of its 2 CCP/PWM channels plus software-PWM on additional GPIO pins, and its integrated USB device port. A host PC application sends channel-update frames over USB CDC, and the PIC firmware generates hardware-timed PWM signals to drive LED strips or dimmer stages. The 48MHz core supports several hundred PWM updates per second without breaking the USB polling interval, while the 5V I/O tolerance simplifies driving FET-driver ICs directly. The 34 GPIO pins are ample for status LEDs, pushbuttons, and rotary-encoder inputs commonly used on stage controllers.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4450T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4450-I/PT | PIC18F4550-I/PT | PIC18F4455-I/PT | PIC18F4458-I/PT | PIC18F46J50-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Program Memory | 16 KB Flash | 16 KB Flash (same die) | 32 KB Flash (+100%) | 24 KB Flash (+50%) | 32 KB Flash (+100%) | 64 KB Flash (+300%) |
| RAM | 768 bytes | 768 bytes (same) | 2048 bytes (+166%) | 2048 bytes (+166%) | 2048 bytes (+166%) | 3892 bytes (+407%) |
| Supply Voltage | 4.2 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 | 4.2 V to 5.5 V | 2.0 V to 3.6 V (3.3V core) |
| USB | FS USB 2.0 Device + transceiver | FS USB 2.0 Device + transceiver (same) | FS USB 2.0 Device + transceiver | FS USB 2.0 Device + transceiver | FS USB 2.0 Device + transceiver | FS USB 2.0 Device + transceiver |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Same-package memory upgrade path (vs PIC18F4550-I/PT)
- Industrial -40C to +85C temperature rating (vs PIC18F4450-E/PT)
- On-chip Full-Speed USB transceiver eliminates external PHY (vs FT232HL-REEL)
- 5V tolerance supports legacy industrial rails (vs PIC18F46J50-I/PT)
Design Notes
The PIC18F4450T-I/PT's internal 3.3V USB regulator is brought out on the VUSB pin (pin 41). Per the Microchip datasheet, VUSB must be decoupled with a 220nF ceramic capacitor placed within 5mm of the pin to keep USB-enumeration noise off the analog rails. If the design is self-powered (not bus-powered), tie VUSB to VDD through a 10k resistor to disable the internal regulator. The main VDD rails require a 100nF decoupling capacitor close to each VDD/VSS pair plus a bulk 10uF tantalum or ceramic to handle USB attach current transients of up to 100 mA.
USB D+ (pin 20) and D- (pin 19) must be routed as a 90-ohm differential pair on the PCB with matched length (delta < 150 mil) and continuous reference plane on the layer below. Keep the pair away from switching signals such as PWM outputs or oscillator traces; a 4x guard trace to ground via stitching improves EMI margin per the USB 2.0 specification. The MCU should be placed within 25mm of the USB connector to keep the differential pair short, and the VUSB capacitor must sit between the MCU and connector without stubs.
Three common PIC18F4450T-I/PT firmware pitfalls: (1) forgetting to configure the oscillator to HS-PLL with the 48 MHz USB clock setting before USB stack init - the device will enumerate only as low-speed; (2) leaving the MCLR pin floating - the part will randomly reset; tie to VDD through a 10k resistor or use an MCP130 reset supervisor for production; (3) not enabling the GIE and PEIE bits before USB interrupt handling, causing the device to enumerate but stall on the first control transfer. Always initialize the CONFIG registers for WDT disable and LVP enable to match your ICSP programmer.
For ADC accuracy on the 10-bit converter, place a 100nF + 10uF decoupling pair close to the AVDD pin (pin 44) and route analog traces away from digital switching signals. The ADC can reach +/- 1 LSB accuracy when the source impedance is below 2.5 kohm and the acquisition time is configured for at least 1.5 us. Using AVSS as the analog ground return and tying it to VSS at a single point near the MCU reduces digital switching noise coupling into the analog measurements. The internal band-gap reference can be used for absolute readings but drifts +/- 5% over temperature, so calibrate in firmware for precision designs.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C. Not AEC-Q100 qualified; AEC-Q100 variants of this family are separate -Q1 part numbers.