PIC18F4455T-I/PT - 48MHz 8-bit FS-USB MCU 24KB Flash | Microchip
MPN: PIC18F4455T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.32 | $6.32 |
| 10 | $5.74 | $57.40 |
| 100 | $5.12 | $512.00 |
| 500 | $4.58 | $2,290.00 |
| 1,000 | $4.1 | $4,100.00 |
PIC18F4455T-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (typically flash), working RAM, and a rich set of peripheral interfaces into one IC. Within the broader semiconductor taxonomy, an 8-bit MCU sits inside the microcontroller category, which itself belongs to integrated circuits and finally to semiconductors. PIC18 microcontrollers use Microchip's enhanced Harvard RISC architecture with 16-bit wide instructions that execute in four oscillator cycles, providing higher code density and throughput than baseline PIC microcontrollers.
Key features include 24KB (12K x 16) flash program memory, 2048 bytes of RAM, a 10-bit ADC with up to 13 channels, two 8-bit and three 16-bit timers, two capture/compare/PWM modules, an enhanced USART (LIN-capable), an MSSP supporting both I2C and SPI up to 10 Mbit/s, and an integrated USB 2.0 full-speed transceiver (12 Mbit/s) with on-chip transceivers and 1.5 kB of dedicated endpoint RAM. nanoWatt power-management technology provides multiple idle and sleep modes for low-power embedded designs.
The device uses a 5V-tolerant CMOS process, includes an 8x8 hardware multiply, a 32 kHz secondary oscillator for real-time-clock operation, and provides two comparators plus a programmable reference. The integrated full-speed USB transceiver removes the need for external USB transceivers, simplifying USB peripherals such as HID, CDC, vendor-class devices, and embedded hosts.
Typical applications include USB peripherals (keyboards, mice, custom HID devices, USB-to-UART bridges), low-cost instrumentation with USB connectivity, embedded data loggers, sensor front-ends with USB data export, LIN slave nodes in automotive body networks, industrial control with USB diagnostics, and educational/development platforms that benefit from the same PIC18 instruction set used across the entire Microchip PIC family.
When designing with this device, ensure the VUSB pin is decoupled with the manufacturer-recommended 220 nF capacitor and that the USB DP/DM traces are routed as a 90-ohm differential pair. Always configure the CONFIG fuses (oscillator, WDT, brown-out, low-voltage programming) before code download to lock the device into the intended operating mode.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F4455T-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 PIC18F4455T-I/PT (same form factor and footprint) — differing in Operating Temperature, Timers, Package, Program Memory (Flash), Serial Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4455-I/PT
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC18F4550T-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4550T-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4553T-I/PT
✅ Drop-In✓ In Stock
$4.5 / Unit
View Datasheet →PIC18F4450T-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F4455T-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 enhanced 8-bit RISC |
| Program Memory (Flash) | 24 KB (12K x 16 words) |
| RAM | 2048 bytes |
| Maximum CPU Frequency | 48 MHz (12 MIPS) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| USB Interface | USB 2.0 Full-Speed (12 Mbit/s), on-chip transceiver |
| ADC | 10-bit, up to 13 channels |
| Timers | Two 8-bit + three 16-bit |
| CCP/PWM Modules | 2 ECCP + 1 (standard) |
| Serial Interfaces | EUSART (LIN-capable), MSSP (I2C + SPI up to 10 Mbit/s) |
| Comparators | 2 with programmable voltage reference |
| Operating Temperature | -40 C to +85 C (industrial, "I" grade) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (per JEDEC J-STD-020) |
| Lead-Free / RoHS | Lead-free, RoHS compliant |
PIC18F4455T-I/PT Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input / programming voltage / digital I/O RE3 |
| Pin 2 | RA0/AN0 — Digital I/O RA0 / analog input AN0 |
| Pin 3 | RA1/AN1 — Digital I/O RA1 / analog input AN1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O RA2 / analog input AN2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O RA3 / analog input AN3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI/C1OUT — Digital I/O RA4 / Timer0 clock input / Comparator 1 output |
| Pin 7 | RA5/AN4/SS/HLVDIN/C2OUT — Digital I/O RA5 / analog input AN4 / SPI slave select / HLVD input / Comparator 2 output |
| Pin 8 | RE0/RD/AN5 — Digital I/O RE0 / Parallel Port D bit 0 / analog input AN5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O RE1 / Parallel Port D write / analog input AN6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O RE2 / Parallel Port D chip select / analog input AN7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI/RA7 — Oscillator crystal input / external clock input / digital I/O RA7 |
| Pin 14 | OSC2/CLKO/RA6 — Oscillator crystal output / system clock output / digital I/O RA6 |
| Pin 15 | RC0/T1OSO/T1CKI — Digital I/O RC0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O RC1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1/P1A — Digital I/O RC2 / CCP1 output / PWM P1A output |
| Pin 18 | RC4/D-/VM — USB D- line (also digital I/O RC4) / external USB transceiver VM input |
| Pin 19 | RC5/D+/VP — USB D+ line (also digital I/O RC5) / external USB transceiver VP input |
| Pin 20 | RC6/TX/CK — Digital I/O RC6 / EUSART TX / EUSART synchronous clock |
| Pin 21 | RC7/RX/DT — Digital I/O RC7 / EUSART RX / EUSART synchronous data |
| Pin 22 | RB0/AN12/INT0/FLT0 — Digital I/O RB0 / analog input AN12 / external interrupt 0 / ECCP fault input |
| Pin 23 | RB1/AN10/INT1 — Digital I/O RB1 / analog input AN10 / external interrupt 1 |
| Pin 24 | RB2/AN8/INT2/VMO — Digital I/O RB2 / analog input AN8 / external interrupt 2 / parallel port VMO |
| Pin 25 | RB3/AN9/CCP2/VPO — Digital I/O RB3 / analog input AN9 / CCP2 output / parallel port VPO |
| Pin 26 | RB4/AN11/KBI0 — Digital I/O RB4 / analog input AN11 / interrupt-on-change KBI0 |
| Pin 27 | RB5/KBI1/PGM — Digital I/O RB5 / interrupt-on-change KBI1 / LVP programming entry |
| Pin 28 | RB6/KBI2/PGC — Digital I/O RB6 / interrupt-on-change KBI2 / ICSP clock |
| Pin 29 | RB7/KBI3/PGD — Digital I/O RB7 / interrupt-on-change KBI3 / ICSP data |
| Pin 30 | VUSB — Internal USB 3.3 V regulator output - decouple with 220 nF |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RD0/SPP0 — Digital I/O RD0 / Streaming Parallel Port data bit 0 |
| Pin 34 | RD1/SPP1 — Digital I/O RD1 / Streaming Parallel Port data bit 1 |
| Pin 35 | RD2/SPP2 — Digital I/O RD2 / Streaming Parallel Port data bit 2 |
| Pin 36 | RD3/SPP3 — Digital I/O RD3 / Streaming Parallel Port data bit 3 |
| Pin 37 | RD4/SPP4 — Digital I/O RD4 / Streaming Parallel Port data bit 4 |
| Pin 38 | RD5/SPP5/P1B — Digital I/O RD5 / Streaming Parallel Port data bit 5 / PWM P1B output |
| Pin 39 | RD6/SPP6/P1C — Digital I/O RD6 / Streaming Parallel Port data bit 6 / PWM P1C output |
| Pin 40 | RD7/SPP7/P1D — Digital I/O RD7 / Streaming Parallel Port data bit 7 / PWM P1D output |
| Pin 41 | RC3/REF0/SCL — Digital I/O RC3 / programmable reference output / I2C clock |
| Pin 42 | RC4/D-/VM — (Note: also RC4 on pin 18) - USB D-/VM tied through internal mux |
| Pin 43 | NC — Not connected (per datasheet pinout table pin 43 of 44-TQFP) |
| Pin 44 | NC — Not connected (per datasheet pinout table pin 44 of 44-TQFP) |
Typical Applications
PIC18F4455T-I/PT is suitable for 6 applications: USB HID Peripherals (Keyboard, Mouse, Custom HID), USB-to-UART / CDC Bridge, Industrial Sensor Front-End with USB Data Export, LIN Bus Slave Node (Automotive Body Electronics), Low-Cost USB Data Logger / Embedded Storage, Educational Microcontroller Platform / Development Board.
USB HID Peripherals (Keyboard, Mouse, Custom HID)
The PIC18F4455T-I/PT's integrated USB 2.0 Full-Speed transceiver with on-chip SIE and 1.5 kB of dedicated endpoint RAM eliminates the need for external USB controllers, making it ideal for USB HID class devices. Its 48 MHz clock generates the precise 48 MHz USB bit-clock domain internally, and the nanoWatt idle modes reduce standby current when the host suspends the bus. Typical designs pair the MCU with a 12 MHz crystal, a 220 nF VUSB decoupling cap and a USB-B or micro-B connector; firmware uses Microchip's free MLA USB stack for HID reports at 1 ms intervals.
Recommended
USB-to-UART / CDC Bridge
The combination of Full-Speed USB, EUSART (LIN-capable) and 24 KB flash makes this part a natural fit for USB-to-UART bridges. The integrated transceiver and dedicated endpoint RAM avoid an external FTDI-class chip, while the EUSART supports baud rates up to the system clock divided by 16. Designs use the CDC class to enumerate as a virtual COM port on the host, eliminating driver installation on modern Windows/macOS/Linux. Power consumption is dominated by the 48 MHz core at ~15 mA active; nanoWatt sleep drops this below 1 uA when the bus is suspended.
Recommended
Industrial Sensor Front-End with USB Data Export
The PIC18F4455T-I/PT's 13-channel 10-bit ADC, dual comparators with programmable voltage reference, and three 16-bit timers let it interface directly with analog sensors, RTDs, thermistors and 4-20 mA loops. Industrial temperature grade (-40C to +85C) handles factory-floor environments, while USB Full-Speed allows fast data export to a host PC for logging or calibration. The MSSP supports SPI sensors at up to 10 Mbit/s and I2C peripherals; the 2 KB RAM buffers intermediate sample streams before USB transmission.
Recommended
LIN Bus Slave Node (Automotive Body Electronics)
The PIC18F4455T-I/PT's LIN-capable EUSART, 5V-tolerant I/O and industrial temperature range suit it for LIN slave nodes controlling door modules, seat adjusters, mirror controls and HVAC dampers. The enhanced core delivers 12 MIPS at 48 MHz, fast enough for LIN 2.x scheduling at 19.2 kbps with margin for the application layer. The 36 I/O pins directly drive relay coils and H-bridges through external FETs, and the 10-bit ADC reads position feedback from potentiometers or Hall sensors.
Recommended
Low-Cost USB Data Logger / Embedded Storage
Self-programmable flash and 2 KB RAM allow a small FAT12/16 file system in firmware for a USB Mass Storage class data logger (the part also supports bulk-only transport with MSC class). The MSSP SPI port at 10 Mbit/s connects directly to an external SPI flash or SD-card adapter for storage extension, while the USB port appears as a removable drive on the host. Industrial temperature grade and nanoWatt sleep (below 1 uA) enable battery-powered loggers that wake on RTC interrupt to record and return to sleep.
Recommended
Educational Microcontroller Platform / Development Board
The PIC18F4455T-I/PT is widely adopted in academic labs and hobbyist development boards because of the free MPLAB X IDE, XC8 compiler, and Microchip's open MLA USB stack. Its 36 I/O pins and rich peripheral set (CCP/PWM, comparators, ADC, USB, EUSART, MSSP) give students a complete embedded platform on a single chip. The 44-TQFP package is breadboard-friendly with carrier PCBs, and the 48 MHz operation exercises the full instruction set without external wait states.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4455T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4455-I/PT | PIC18F4550T-I/PT | PIC18LF4550T-I/PT | PIC18F4553T-I/PT |
|---|---|---|---|---|---|
| Brand | 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 |
| Program Memory (Flash) | 24 KB | 24 KB | 32 KB | 32 KB | 32 KB |
| RAM | 2048 bytes | 2048 bytes | 2048 bytes | 2048 bytes | 2048 bytes |
| Maximum Clock Speed | 48 MHz (12 MIPS) | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Supply Voltage | 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 5.5 V | 4.2 V to 5.5 V |
| USB Interface | USB 2.0 Full-Speed, integrated | USB 2.0 Full-Speed, integrated | USB 2.0 Full-Speed, integrated | USB 2.0 Full-Speed, integrated | USB 2.0 Full-Speed, integrated |
| ADC Resolution | 10-bit | 10-bit | 10-bit | 10-bit | 12-bit (improved) |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| 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 |
Key Differentiators
- Integrated USB 2.0 Full-Speed transceiver with on-chip SIE and dedicated endpoint RAM (vs PIC18F4450T-I/PT)
- Lower cost at equivalent memory tier compared to PIC18F4550 (vs PIC18F4550T-I/PT)
- Full nanoWatt power management with multiple idle and sleep modes (vs PIC18LF4550T-I/PT)
Design Notes
Decouple VDD pins 11 and 32 with 100 nF ceramic capacitors placed within 3 mm of each pin, and add a bulk 4.7-10 uF tantalum or ceramic capacitor on the supply rail. For USB operation, place a 220 nF capacitor on VUSB (pin 30) - this is the internal 3.3 V USB regulator output and MUST be present for compliant Full-Speed signalling. Connect both VSS pins (12 and 31) to a low-impedance ground plane to minimize digital switching noise on the analog subsystem.
Route USB D+ (pin 19) and D- (pin 18) as a 90-ohm differential pair with matched length, keeping the pair as short as possible (typically under 50 mm). Avoid routing the USB pair near high-frequency switching signals. Keep the crystal traces to pins 13 (OSC1) and 14 (OSC2) short and symmetric, and place the crystal load capacitors (typically 22-33 pF) close to the MCU. Reference Microchip ANSEL USB hardware design guide for full PCB layout recommendations.
Estimated: At 48 MHz with all peripherals active, the PIC18F4455T-I/PT typically draws ~15 mA from VDD; enable the nanoWatt sleep modes in idle firmware to drop quiescent current below 1 uA. The CONFIG fuses (oscillator selection, WDT, brown-out reset, low-voltage programming) must be configured before code download - leaving the factory defaults can result in an unconfigured clock source and the MCU appearing unresponsive to ICSP. Do not connect MCLR directly to VDD without a 10 kohm pull-up; the MCLR pin requires the reset signal to be high-impedance during normal operation.
When using the ADC, place analog input traces away from digital switching signals and tie unused analog pins to VDD or VSS (not left floating). Set the A/D acquisition time appropriately for the source impedance - for 10 kohm source impedance use at least 4 uS TACQ. The internal band-gap reference requires 20 uS settling time after enabling. Use the digital I/O ANSEL register to disable digital input buffers on ADC-active pins to reduce input leakage to less than 50 nA.
Compliance Information
RoHS and REACH compliant per Microchip product page; lead-free TQFP package. Not AEC-Q100 qualified - for automotive applications use PIC18F4455-I/PT in industrial designs or contact Microchip for AEC-Q100 grade options. MSL Level 3 floor life per JEDEC J-STD-020.