PIC18F4450T-I/ML - 48MHz 8-bit USB MCU, 16KB Flash | Microchip
MPN: PIC18F4450T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.95 | $5.95 |
| 10 | $5.36 | $53.60 |
| 100 | $4.78 | $478.00 |
| 500 | $4.3 | $2,150.00 |
| 1,000 | $3.83 | $3,830.00 |
PIC18F4450T-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), working memory (RAM), and programmable peripherals into one package. PIC18F devices belong to Microchip's enhanced 8-bit architecture family, sitting above the baseline PIC16 line and below the 16-bit dsPIC and 32-bit PIC32 families. The PIC18F4450 specifically targets USB-aware embedded designs by combining a Full-Speed USB 2.0 peripheral with nanoWatt power management, making it part of Microchip's "peripheral-rich" legacy USB portfolio.
Key features include 16KB Flash organized as 8K x 16 words, 768 bytes of RAM, 256 bytes of EEPROM, a 10-bit ADC with up to 13 input channels, two analog comparators, a Capture/Compare/PWM (CCP) module and an Enhanced CCP module, two USARTs, a Master I2C/SPI port, 34 digital I/O lines, and four timer modules. The integrated Full-Speed USB 2.0 SIE supports 1.5 Mbps Low-Speed and 12 Mbps Full-Speed operation with on-chip transceiver, eliminating the need for external USB PHY components.
Architecturally the PIC18F4450 uses an enhanced Harvard RISC core with 16-bit instructions and 8-bit data path, hardware multiplier, 31-level hardware stack, and 75 instructions including multiply and divide. The nanoWatt technology provides multiple power-managed modes (Run, Idle, Sleep, and deep Sleep variants) that reduce quiescent current to microampere levels - a critical feature for battery-powered or USB-suspended devices. The Phase-Locked Loop allows the 48MHz USB clock to be derived from a low-frequency crystal.
Typical applications include USB-to-UART bridges, HID-class peripherals (keyboards, mice, game controllers), USB sensors and data loggers, industrial USB instrumentation, bootloader and firmware-update hosts, and point-of-sale terminals. The combination of USB, ADC, and PWM makes it suitable for motor-control USB dongles, lab data acquisition front-ends, and educational embedded platforms that require a direct PC connection.
When designing with this part, mind the QFN-44 exposed-pad requirement: the central pad must be soldered to a properly sized ground copper pour for thermal and electrical performance. Use Microchip's MPLAB X IDE and the XC8 compiler for firmware development; the USB stack is provided in the Microchip Libraries for Applications (MLA) framework. Migrating to newer designs may favor PIC18F46J50 or PIC18F4550 families for additional memory, but the PIC18F4450 remains a low-cost Full-Speed USB solution for cost-sensitive legacy products.
Drop-in alternatives for PIC18F4450T-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 PIC18F4450T-I/ML (same form factor and footprint) — differing in Core Architecture, Package, Operating Temperature, Timers, Digital I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4450-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F4550T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.1 / Unit
View Datasheet →PIC18F4455T-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F4458T-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.25 / Unit
View Datasheet →PIC18F46J50-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F4450T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18F enhanced 8-bit RISC |
| Program Memory (Flash) | 16 KB (8K x 16) |
| RAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 48 MHz (16 MIPS) |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| USB Interface | USB 2.0 Full-Speed (12 Mbps) + Low-Speed (1.5 Mbps) on-chip SIE/transceiver |
| Digital I/O Pins | 34 |
| ADC | 10-bit, up to 13 channels |
| Analog Comparators | 2 |
| CCP/ECCP Modules | 1 CCP + 1 ECCP |
| Timers | 4 (Timer0/Timer1/Timer2/Timer3) |
| Serial Interfaces | 1x EUSART, 1x MSSP (I2C/SPI) |
| Operating Temperature | -40 C to +85 C (industrial, "I" grade) |
| Package | 44-pin QFN (8x8 mm) with exposed pad (ML) |
| Mounting Type | Surface Mount |
| Packaging Form | Tape & Reel (T suffix) |
| Instruction Set | 75 instructions including hardware multiply |
| Power-Saving Modes | Run, Idle, Sleep, deep Sleep (nanoWatt technology) |
| RoHS Status | Compliant |
PIC18F4450T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / analog input channel 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / analog input channel 1 |
| Pin 3 | RA2/AN2/VREF- — PORTA bit 2 / analog input channel 2 / ADC negative reference |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / analog input channel 3 / ADC positive reference |
| Pin 5 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 6 | RA5/AN4/SS/HLVDIN — PORTA bit 5 / analog input 4 / SSP slave select / HLVD input |
| Pin 7 | VDD — Positive supply voltage (2.0V to 5.5V) |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — Crystal input / external clock in / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — Crystal output / clock out / PORTA bit 6 |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / ECCP1 output |
| Pin 14 | RC3 — PORTC bit 3 |
| Pin 15 | RC4/D-/VM — PORTC bit 4 / USB D- / external USB transceiver VM input |
| Pin 16 | RC5/D+/VP — PORTC bit 5 / USB D+ / external USB transceiver VP input |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / EUSART TX / clock output |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / EUSART RX / data output |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0V to 5.5V) |
| Pin 21 | RB0/AN12/INT0/FLT0 — PORTB bit 0 / analog input 12 / external interrupt 0 / ECCP fault |
| Pin 22 | RB1/AN10/INT1 — PORTB bit 1 / analog input 10 / external interrupt 1 |
| Pin 23 | RB2/AN8/INT2 — PORTB bit 2 / analog input 8 / external interrupt 2 |
| Pin 24 | RB3/AN9/CCP2 — PORTB bit 3 / analog input 9 / CCP2 output |
| Pin 25 | RB4/AN11/KBI0 — PORTB bit 4 / analog input 11 / KBI interrupt 0 |
| Pin 26 | RB5/KBI1/PGM — PORTB bit 5 / KBI interrupt 1 / LVP program |
| Pin 27 | RB6/KBI2/PGC — PORTB bit 6 / KBI interrupt 2 / ICD clock |
| Pin 28 | RB7/KBI3/PGD — PORTB bit 7 / KBI interrupt 3 / ICD data |
| Pin 29 | VUSB — Internal 3.3V USB voltage regulator output (decouple to VSS) |
| Pin 30 | RD0 — PORTD bit 0 |
| Pin 31 | RD1 — PORTD bit 1 |
| Pin 32 | RD2 — PORTD bit 2 |
| Pin 33 | RD3 — PORTD bit 3 |
| Pin 34 | RD4 — PORTD bit 4 |
| Pin 35 | RD5/P1B — PORTD bit 5 / Enhanced PWM 1B output |
| Pin 36 | RD6/P1C — PORTD bit 6 / Enhanced PWM 1C output |
| Pin 37 | RD7/P1D — PORTD bit 7 / Enhanced PWM 1D output |
| Pin 38 | VSS — Ground reference |
| Pin 39 | VDD — Positive supply voltage (2.0V to 5.5V) |
| Pin 40 | RE0/RD — PORTE bit 0 / parallel slave port read control |
| Pin 41 | RE1/WR — PORTE bit 1 / parallel slave port write control |
| Pin 42 | RE2/CS — PORTE bit 2 / parallel slave port chip select |
| Pin 43 | AVDD — Analog positive supply (tie to VDD) |
| Pin 44 | AVSS — Analog ground (tie to VSS) |
Typical Applications
PIC18F4450T-I/ML is suitable for 6 applications: USB-to-UART Bridge Dongle, USB HID Peripheral (Keyboard/Mouse/Gamepad), USB Data-Acquisition Front End, Industrial USB Sensor Hub, USB Bootloader / Firmware Update Host, Educational / Maker USB Development Platform.
USB-to-UART Bridge Dongle
The PIC18F4450T-I/ML's integrated Full-Speed USB 2.0 SIE and EUSART make it ideal for implementing a low-cost USB-to-UART (CDC-ACM) bridge. A 12 Mbps USB link converts to RS-232-style asynchronous serial at 300 to 115200 baud using the on-chip EUSART plus interrupt-driven buffering. Its 16 KB Flash accommodates the CDC class driver and protocol stack, while the 48 MHz CPU provides enough headroom for full-duplex flow control. Operating from 5 V bus power with on-chip 3.3 V regulator simplifies the design to a single-supply dongle.
Recommended
USB HID Peripheral (Keyboard/Mouse/Gamepad)
The PIC18F4450T-I/ML serves as the controller core for USB HID-class devices such as keyboards, mice, remote controls, and game controllers. The on-chip USB SIE handles enumeration and report generation with minimal firmware overhead, while 34 digital I/O lines scan matrices up to 8x8 in size. The nanoWatt Sleep modes drop quiescent current to microampere levels, extending battery life in wireless HID dongles. With 768 bytes of RAM, the part supports multi-button HID reports including keyboard, mouse, and media-control composite devices without external memory.
Recommended
USB Data-Acquisition Front End
The PIC18F4450T-I/ML's 10-bit ADC with up to 13 input channels plus its Full-Speed USB interface enable a compact USB data-acquisition module for sensors, lab instrumentation, and process monitoring. At approximately 100 ksps ADC throughput, the MCU streams 8 or more analog channels over USB bulk transfers to a host PC running a Python or LabVIEW acquisition script. The 256-byte EEPROM stores calibration coefficients, while the 768-byte RAM serves as a sample buffer between USB packets. With 2.0 V to 5.5 V supply range, the same PCB can power from 3.3 V sensor rails or 5 V USB bus power.
Recommended
Industrial USB Sensor Hub
In factory-automation and process-control contexts, the PIC18F4450T-I/ML aggregates multiple sensor inputs (analog, digital, I2C, SPI) and exposes them as a USB CDC or vendor-class device to a host PC or HMI panel. The -40 C to +85 C industrial temperature range supports use in cabinets and unconditioned panels. The MSSP peripheral acts as an I2C master for digital-temperature, pressure, or accelerometer sensors, while the 10-bit ADC reads 4-20 mA current loops through external shunt resistors. Robust firmware upgrade via the USB bootloader reduces field-service costs.
Recommended
USB Bootloader / Firmware Update Host
The PIC18F4450T-I/ML is a natural fit for USB-based bootloader targets, allowing in-field firmware updates over the same USB port the application uses. The 16 KB Flash supports the standard Microchip HID bootloader (~2 KB) plus a 14 KB application region, which is sufficient for many industrial firmware payloads. The on-chip 256-byte EEPROM stores bootloader metadata such as version numbers and image-validation hashes. The 5 V-tolerant I/O and integrated USB pull-up eliminate the need for external USB protection circuitry in benign environments.
Recommended
Educational / Maker USB Development Platform
The PIC18F4450T-I/ML is widely used in university embedded-systems courses and hobbyist projects because it combines USB, ADC, PWM, and digital I/O on a single 5 V-tolerant 8-bit MCU with free MPLAB X IDE and XC8 toolchain support. A typical application is a USB-controlled oscilloscope front-end, a POV-LED text scroller with USB configuration, or a class-D audio DAC controlled over USB. The QFN-44 (8x8 mm) exposed-pad package is hand-solderable with hot air and integrates easily on through-hole-friendly breakout boards, lowering the entry barrier for student projects.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4450T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4450-I/ML | PIC18F4550T-I/ML | PIC18F4455T-I/ML | PIC18F4458T-I/ML | PIC18F46J50-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN (8x8 mm) with EP | 44-pin QFN (8x8 mm) with EP | 44-pin QFN (8x8 mm) with EP | 44-pin QFN (8x8 mm) with EP | 44-pin QFN (8x8 mm) with EP | 44-pin QFN (8x8 mm) with EP |
| Flash Memory | 16 KB | 16 KB | 32 KB | 24 KB | 16 KB | 64 KB |
| RAM | 768 bytes | 768 bytes | 2048 bytes | 768 bytes | 2048 bytes | 3904 bytes |
| Maximum CPU Speed | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) | 48 MHz (16 MIPS) |
| USB Interface | USB 2.0 Full-Speed + Low-Speed | USB 2.0 Full-Speed + Low-Speed | USB 2.0 Full-Speed + Low-Speed | USB 2.0 Full-Speed + Low-Speed | USB 2.0 Full-Speed + Low-Speed | USB 2.0 Full-Speed + Low-Speed |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 12 channels | 10-bit, 13 channels |
| Supply Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 3.6 V |
| Operating Temperature | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) |
Key Differentiators
- On-chip USB Full-Speed transceiver eliminates external PHY (vs PIC18F4550T-I/ML (same family, double the Flash))
- Industrial 8-bit PIC core with mature toolchain support (vs PIC18F46J50-I/ML (J-series low-power variant))
- Compact QFN-44 (8x8 mm) with exposed pad for thermal performance (vs PIC18F4450-I/P (DIP-40 variant))
Design Notes
The 44-pin QFN (8x8 mm) package has a central exposed thermal pad that MUST be soldered to a ground copper pour for electrical and thermal performance. Use an array of thermal vias (typically 0.3 mm drill, 0.6 mm pitch, 9-13 vias) under the EP to conduct heat into inner ground planes. Without proper EP soldering, the part will exceed thermal limits at moderate load currents and the USB transceiver may show degraded signal integrity due to lifted ground reference.
Place the 12 MHz crystal or resonator within 5 mm of the OSC1/OSC2 pins and keep its traces short and symmetric. Route the USB D+/D- lines as a 90-ohm differential pair with no stubs and keep them at least 3 mm away from clock signals and switching regulators. Add 10 nF + 4.7 uF decoupling on each VDD/VSS pair, plus 100 nF + 10 uF on AVdd/AVss for the ADC reference. VUSB requires a 220 nF decoupling capacitor placed within 2 mm of the pin per the USB specification.
Do not assume USB works at VDD below 4.2 V - the datasheet specifies USB Full-Speed compliance only above 4.2 V. For 3.3 V-only designs, use a PIC18F4xJ50 or PIC18F2x/4xK50 series instead. Be careful with the I/O pin mapping: RC4 (D-) and RC5 (D+) are fixed USB pins and cannot be reassigned as general-purpose I/O when the USB SIE is enabled. The MCLR pin must be pulled high through a 10 kohm resistor; leaving it floating causes erratic resets.
Configure the nanoWatt Sleep mode for USB Suspend to drop quiescent current below 1 uA and comply with USB 2.0 suspend-current specifications (2.5 mA high-power, 500 uA for low-power USB devices). Use Idle mode for peripherals-active-but-CPU-stopped scenarios, and the deep-Sleep modes for battery-powered data loggers that wake from RTCC or external interrupts. Verify the current budget at the worst-case operating voltage (typically 5.5 V) since quiescent current increases with VDD.
Compliance Information
RoHS compliant per Microchip product environmental compliance statement. AEC-Q100 variants (with -VAO suffix) are available from Microchip for automotive applications requiring PPAP documentation. Standard PIC18F4450T-I/ML is not AEC-Q100 qualified.
