PIC18F4455-I/PT - 8-Bit 48MHz 24KB USB MCU 44-TQFP | Microchip
MPN: PIC18F4455-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.45 | $7.45 |
| 10 | $6.92 | $69.20 |
| 100 | $6.05 | $605.00 |
| 500 | $5.42 | $2,710.00 |
| 1,000 | $4.85 | $4,850.00 |
PIC18F4455-I/PT Overview
What is a PIC18 microcontroller? PIC18 is Microchip's high-performance 8-bit family built on a RISC architecture that delivers up to 16 MIPS performance and uses an enhanced instruction set including a C-friendly flat memory model. Within the broader taxonomy, PIC18F devices sit between baseline PIC10/12/16 families and PIC24/dsPIC16-bit families, offering a balance of low cost, low power (nanoWatt technology), and rich peripherals including USB, CAN, and ADC. They are widely used in consumer, industrial, and automotive embedded applications where 8-bit simplicity and proven toolchains are preferred over 32-bit complexity.
The PIC18F4455 specifically adds an integrated Full-Speed USB 2.0 transceiver (12 Mbit/s), supporting both low-speed and full-speed USB operation without external transceivers. The device includes three serial communication ports: USB, I2C, SPI (up to 10 Mbit/s), and an asynchronous EUSART with LIN master/slave capability. On-chip peripherals include a 10-bit ADC with up to 13 channels, multiple 8-bit and 16-bit timers, and nanoWatt power management with multiple low-power sleep modes.
Architecturally, the PIC18F4455 uses a Harvard architecture with separate program and data buses, an 8-bit ALU, and a hardware multiply unit supporting 8x8 single-cycle multiplication. The integrated SIE (Serial Interface Engine) handles USB protocol automatically, dramatically simplifying USB device firmware. With 24 KB Flash and 2 KB RAM, the device comfortably fits full-speed USB stacks such as Microchip's Microchip Libraries for Applications (MLA) and supports CDC, HID, and vendor-class USB implementations.
Typical applications include USB-based sensor interfaces, HID peripherals (keyboards, mice, game controllers), USB-to-UART bridges, industrial data loggers with USB connectivity, embedded web servers (via CDC-ECM or RNDIS), and automotive LIN bus gateway nodes. The wide 2.0 V to 5.5 V supply range and nanoWatt sleep modes make the device attractive for battery-powered USB devices.
When designing with the PIC18F4455-I/PT, pay attention to the USB D+/D- pin routing - the differential pair must be 90 ohm impedance-matched, length-matched, and isolated from noisy digital traces. Use a 20 MHz external crystal with the on-chip PLL to derive the 48 MHz USB clock; 48 MHz is mandatory for Full-Speed USB operation. Adequate decoupling (100 nF plus 4.7 uF bulk) should be placed close to VDD/VSS pairs.
This page consolidates distributor pricing, drop-in PIC18F alternatives in the same TQFP-44 footprint, and practical USB-embedded design considerations not found in the manufacturer datasheet alone, enabling faster BOM validation and supply-chain risk assessment for production engineering teams.
Drop-in alternatives for PIC18F4455-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 PIC18F4455-I/PT (same form factor and footprint) — differing in Operating Temperature, Timers, Package, ADC, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4550-I/PT
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC18F4455T-I/PT
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F4550T-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4431-I/PT
✅ Drop-In✓ In Stock
$4.79 / Unit
View Datasheet →PIC18F43K22-I/PT
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F4420-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4455-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Maximum CPU Frequency | 48 MHz |
| Performance | 12 MIPS |
| Program Memory (Flash) | 24 KB (12K x 16) |
| Data Memory (RAM) | 2048 bytes |
| EEPROM | 256 bytes |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| I/O Pins | 36 |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| USB Module | Full-Speed USB 2.0 (12 Mbit/s) SIE on-chip |
| ADC | 10-bit, up to 13 channels |
| Serial Interfaces | USB, I2C, SPI (10 Mbit/s), EUSART (LIN-capable) |
| Timers | Multiple 8-bit and 16-bit timers |
| Operating Temperature | -40 C to +85 C (Industrial -I suffix) |
| RoHS Status | Compliant |
PIC18F4455-I/PT Pin Configuration
| Pin 1 | RC2/CCP1 — I/O port C bit 2 / CCP1 PWM output |
| Pin 2 | RC4/D-/VMO — I/O port C bit 4 / USB D- / ICSP data |
| Pin 3 | RC5/D+/VPP — I/O port C bit 5 / USB D+ / ICSP VPP |
| Pin 4 | RC6/TX/CK — I/O port C bit 6 / EUSART TX / clock |
| Pin 5 | RC7/RX/DT — I/O port C bit 7 / EUSART RX / data |
| Pin 6 | RD0/SPP0 — I/O port D bit 0 / Streaming Parallel Port |
| Pin 7 | RD1/SPP1 — I/O port D bit 1 |
| Pin 8 | RD2/SPP2 — I/O port D bit 2 |
| Pin 9 | RD3/SPP3 — I/O port D bit 3 |
| Pin 10 | RD4/SPP4 — I/O port D bit 4 |
| Pin 11 | RD5/SPP5/P1B — I/O port D bit 5 / PWM P1B |
| Pin 12 | RD6/SPP6/P1C — I/O port D bit 6 / PWM P1C |
| Pin 13 | RD7/SPP7/P1D — I/O port D bit 7 / PWM P1D |
| Pin 14 | VSS — Ground reference |
| Pin 15 | VDD — Positive supply (2.0 V to 5.5 V) |
| Pin 16 | RB0/AN12/INT0 — I/O port B bit 0 / ADC ch 12 / INT0 |
| Pin 17 | RB1/AN10/INT1 — I/O port B bit 1 / ADC ch 10 / INT1 |
| Pin 18 | RB2/AN8/INT2 — I/O port B bit 2 / ADC ch 8 / INT2 |
| Pin 19 | RB3/AN9/CCP2 — I/O port B bit 3 / ADC ch 9 / CCP2 |
| Pin 20 | RB4/AN11/KBI0 — I/O port B bit 4 / ADC ch 11 / KBI0 |
| Pin 21 | RB5/KBI1/PGM — I/O port B bit 5 / KBI1 / LVP PGM |
| Pin 22 | RB6/KBI2/PGC — I/O port B bit 6 / KBI2 / ICSP PGC |
| Pin 23 | RB7/KBI3/PGD — I/O port B bit 7 / KBI3 / ICSP PGD |
| Pin 24 | VUSB — USB internal 3.3V regulator output |
| Pin 25 | MCLR/VPP/RE3 — Master Clear reset / ICSP VPP / port E bit 3 |
| Pin 26 | OSC1/CLKI/RA7 — Crystal input / ext clock / port A bit 7 |
| Pin 27 | OSC2/CLKO/RA6 — Crystal output / clock out / port A bit 6 |
| Pin 28 | RC0/T1OSO/T13CKI — I/O port C bit 0 / Timer1 oscillator out |
| Pin 29 | RC1/T1OSI/CCP2 — I/O port C bit 1 / Timer1 oscillator in / CCP2 |
| Pin 30 | RC3/CCP1 — I/O port C bit 3 / CCP1 PWM |
| Pin 31 | RA0/AN0 — I/O port A bit 0 / ADC ch 0 |
| Pin 32 | RA1/AN1 — I/O port A bit 1 / ADC ch 1 |
| Pin 33 | RA2/AN2/VREF- — I/O port A bit 2 / ADC ch 2 / VREF- |
| Pin 34 | RA3/AN3/VREF+ — I/O port A bit 3 / ADC ch 3 / VREF+ |
| Pin 35 | RA4/T0CKI — I/O port A bit 4 / Timer0 clock input |
| Pin 36 | RA5/AN4/SS — I/O port A bit 5 / ADC ch 4 / SPI slave select |
| Pin 37 | RE0/RD/AN5 — I/O port E bit 0 / parallel read / ADC ch 5 |
| Pin 38 | RE1/WR/AN6 — I/O port E bit 1 / parallel write / ADC ch 6 |
| Pin 39 | RE2/CS/AN7 — I/O port E bit 2 / parallel CS / ADC ch 7 |
| Pin 40 | VDD — Positive supply (2.0 V to 5.5 V) |
| Pin 41 | VSS — Ground reference |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC18F4455-I/PT is suitable for 6 applications: USB HID Keyboard / Mouse, USB-to-UART Bridge, Industrial USB Data Logger, LIN Bus Gateway Node, USB Embedded Web Server (CDC-ECM / RNDIS), USB Vendor-Class Sensor Interface.
USB HID Keyboard / Mouse
The PIC18F4455-I/PT is widely used as a USB HID device controller in low-cost keyboards, mice, and pointing devices. Its integrated Full-Speed USB 2.0 SIE handles HID descriptor, endpoint, and interrupt-IN transfer handling without external transceivers, reducing BOM by $1-$2 versus MCU-plus-TUSB-type solutions. The 48 MHz CPU and 24 KB Flash fit complete HID boot-keyboard or composite HID-Mouse firmware from Microchip's MLA stack, while the 2 KB RAM handles HID report buffers and debouncing state machines. The on-chip 3.3V regulator (VUSB pin) powers the USB pull-up; nanoWatt suspend mode draws <1 uA when the host goes to S3 sleep, making the part ideal for bus-powered peripherals.
Recommended
USB-to-UART Bridge
A classic use case for the PIC18F4455-I/PT is a USB-CDC virtual COM port bridge replacing legacy RS-232 ports. The on-chip USB SIE and EUSART cooperate to deliver up to 921.6 kbitus through the CDC class driver built into Windows, macOS, and Linux kernels. The 48 MHz CPU and 2 KB RAM are sufficient for Microchip's CDC Basic demonstration firmware without external memory, and the 13-channel 10-bit ADC can be exposed as additional vendor endpoints for diagnostics. Designers can add opto-isolation with the 2.0-5.5 V supply range for industrial USB-isolated bridges. Compared to FTDI bridges, the PIC18F4455-I/PT avoids external bridge ICs entirely while keeping firmware updatable in the field.
Recommended
Industrial USB Data Logger
The PIC18F4455-I/PT serves as the controller for industrial data loggers with USB mass-storage class output (MSC / FAT-FS) and sensor logging via I2C/SPI peripherals. With 24 KB Flash, the firmware fits an SD-card FAT-FS plus sensor drivers (BME280, MPU-6050, MAX31855 thermocouple). The wide 2.0-5.5 V supply range and -40 C to +85 C industrial temperature rating make the part suitable for factory-floor loggers, while nanoWatt sleep modes enable multi-month battery operation between USB plug-ins. The on-chip 3.3V regulator can power an external SPI Flash or SD card slot directly, minimizing BOM cost.
Recommended
LIN Bus Gateway Node
The PIC18F4455-I/PT's EUSART supports LAN master/slave mode, making the device a capable gateway between a host's USB port and an automotive LIN bus. The 48 MHz CPU and 24 KB Flash comfortably fit LAN spec 2.x stacks including diagnostic transport layers (ISO 14229 over LIN), while the 10-bit ADC and multiple timers handle signal conditioning for automotive sensors. The USB interface allows PC-based diagnostics tools (e.g., proprietary service tools) to access vehicle networks without an external gateway IC, reducing cost in aftermarket automotive test equipment.
Recommended
USB Embedded Web Server (CDC-ECM / RNDIS)
Using the CDC-ECM or RNDIS class driver, the PIC18F4455-I/PT can present itself as a USB Ethernet adapter to the host, allowing HTTP servers to bind to a virtual NIC. With 24 KB Flash and the Microchip MLA TCP/IP lite stack, an embedded web-server configuration page or REST endpoint is achievable for IoT provisioning, configuration, and diagnostics. The on-chip USB SIE handles Ethernet over USB protocol framing; designers only need to implement the HTTP parser and JSON handler. This is a powerful option for low-cost field service tools, industrial sensor modules, and embedded IoT edge nodes that need a USB-based management interface without wireless silicon.
Recommended
USB Vendor-Class Sensor Interface
The PIC18F4455-I/PT is ideal as a USB vendor-class controller for low-latency sensor interfaces (e.g., IMUs, gas sensors, spectrometers). Vendor-class endpoints avoid kernel-driver dependencies, achieving high throughput on Windows / macOS / Linux with custom driver pairs. The 13-channel 10-bit ADC plus SPI (up to 10 Mbitus) interfaces external 16/24-bit ADCs and sensors at high sample rates, while the 48 MHz CPU handles DMA-style buffering and endpoint completion. Compared to a generic CDC bridge, vendor-class offers lower latency and tighter timing guarantees for real-time sensor streaming and lab instrumentation.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4455-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4550-I/PT | PIC18F4455T-I/PT | PIC18F4550T-I/PT | PIC18F43K22-I/PT | PIC18F4431-I/PT | PIC18F4420-I/PT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP (10x10) | 44-pin TQFP (10x10) - same | 44-pin TQFP (10x10) - same | 44-pin TQFP (10x10) - same | 44-pin TQFP (10x10) - same | 44-pin TQFP (10x10) - same | 44-pin TQFP (10x10) - same |
| Flash Memory | 24 KB | 32 KB | 24 KB | 32 KB | 32 KB | 16 KB | 16 KB |
| RAM | 2048 bytes | 2048 bytes | 2048 bytes | 2048 bytes | 1536 bytes | 768 bytes | 768 bytes |
| USB Module | Full-Speed USB 2.0 on-chip | Full-Speed USB 2.0 on-chip | Full-Speed USB 2.0 on-chip | Full-Speed USB 2.0 on-chip | No USB | No USB | No USB |
| CPU Frequency | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 48 MHz / 12 MIPS | 64 MHz / 16 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS |
| Operating 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 | 1.8 V to 5.5 V (XLP) | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Supply Voltage | 4.2 V to 5.5 V (with USB) | 4.2 V to 5.5 V (with USB) | 4.2 V to 5.5 V (with USB) | 4.2 V to 5.5 V (with USB) | N/A (no USB) | N/A (no USB) | N/A (no USB) |
Key Differentiators
- Integrated Full-Speed USB 2.0 with on-chip SIE (vs PIC18F43K22-I/PT)
- Larger Flash than 28-pin PIC18F2455 (vs PIC18F2455-I/SP)
- Lower cost than PIC18F4550 for firmware fitting 24 KB (vs PIC18F4550-I/PT)
Design Notes
USB D+ (pin 3) and D- (pin 2) differential pair must be 90 ohm differential impedance-controlled, length-matched within 150 mil, and isolated from noisy digital traces on the PCB. Place a common-mode choke or ferrite bead between the MCU and USB connector to suppress EMI. Route D+/D- over a continuous ground plane with no splits. Reference: Microchip AN2336 'USB PCB Layout Guidelines'.
The PIC18F4455-I/PT requires VUSB pin 19 to be decoupled with a 220 nF (or 470 nF) capacitor; this is the internal 3.3V LDO output that supplies the USB transceiver. The internal 3.3V LDO cannot supply VDD to external loads; use an external regulator for VDD. The 20 MHz crystal on OSC1/OSC2 (pins 26/27) must use 20 pF load capacitors with traces kept short (<200 mil).
Place a 100 nF decoupling capacitor within 2 mm of each VDD pin (15 and 40) plus a single 4.7 uF bulk capacitor near the part. Use wide power planes for VDD/VSS to handle 50 mA peak USB enumeration inrush. If using self-powered USB mode, install a 10 uF capacitor on VBUS to meet USB-IF inrush requirements and to prevent soft-start voltage dips.
Estimated: PIC18F4455-I/PT code size for a typical CDC stack is approximately 12-15 KB. Do not exceed 24 KB Flash - rebuild with MPASMX optimization or migrate to PIC18F4550-I/PT for larger stacks. Always configure CONFIG1L for HS-PLL USB clock mode (HS oscillator + PLL enabled) when using a 20 MHz crystal; using XT mode disables USB. Reference: DS39632D datasheet CONFIGURATION REGISTERS section.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade (-40 to +85 C). USB compliance tested per USB-IF Full-Speed chapter 9.