PIC18F66J50T-I/PT - 8-Bit 48MHz USB MCU, 64KB Flash | Microchip
MPN: PIC18F66J50T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.95 | $7.95 |
| 10 | $7.15 | $71.50 |
| 100 | $6.4 | $640.00 |
| 500 | $5.7 | $2,850.00 |
| 1,000 | $5.1 | $5,100.00 |
PIC18F66J50T-I/PT Overview
What is a microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), data memory (RAM), and a rich set of peripherals such as timers, ADCs, communication interfaces, and I/O pins. PIC18 microcontrollers use Microchip's 8-bit RISC architecture with a 16-bit instruction word optimized for deterministic real-time response. The 18J sub-family targets low-voltage, USB-enabled applications in the PIC18 hierarchy (PIC10/12/16/18 -> PIC18 -> PIC18J -> PIC18F66J50).
Key features of the PIC18F66J50 include Full-Speed USB 2.0 device/host/OTG support with on-chip transceiver, four serial communication interfaces (FS-USB, MI2C/SMBus, SPI up to 10 Mbit/s, and an asynchronous LIN-capable EUSART), nanoWatt power management with multiple low-power sleep modes, and self-programmable Flash under ICSP. The integrated peripheral set also includes multiple capture/compare/PWM modules, 10-bit ADC, comparators, and a 54-pin I/O count.
Technically the part is built on a low-voltage CMOS process and provides enhanced Flash memory with self-write capability, allowing field firmware updates without external bootloaders. Hardware multipliers and a 16-bit wide instruction path deliver up to 16 MIPS throughput, while the dedicated USB SIE offloads protocol handling from the CPU, freeing cycles for application logic.
Typical applications include USB peripherals such as HID input devices, CDC virtual COM ports, and mass-storage bridges, as well as low-voltage sensor nodes with USB diagnostics ports, industrial data loggers, point-of-sale terminals, and embedded host applications such as printers or barcode scanners. The part also suits LIN-connected automotive body controllers via the LIN-capable EUSART.
When designing with this device, ensure the VUSB 3.3V LDO is properly decoupled (typically 0.47 uF on VUSB) and use a 12 MHz external crystal or the internal 31 kHz RTCC source per the datasheet's oscillator guidance. Verify that downstream code is built against the PIC18FJ peripheral library to avoid SFR-name mismatches with non-J variants.
This page synthesizes distributor pricing, verified drop-in alternatives in the same 64-pin TQFP footprint, and practical design notes not found in the manufacturer datasheet, giving purchasing and engineering teams a single decision point for cross-referencing PIC18F66J50T-I/PT candidates.
Drop-in alternatives for PIC18F66J50T-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 PIC18F66J50T-I/PT (same form factor and footprint) — differing in ADC, Operating Temperature, Package, Program Memory (Flash), Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F66J50-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F66J55-I/PT
✅ Drop-In✓ In Stock
$4.31 / Unit
View Datasheet →PIC18F65J50T-I/PT
✅ Drop-In✓ In Stock
$3.3 / Unit
View Datasheet →PIC18F66J15T-I/PT
✅ Drop-In✓ In Stock
$6.72 / Unit
View Datasheet →PIC18F67J50T-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.1 / Unit
View Datasheet →PIC18F66J50T-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit RISC, 16-bit instruction word) |
| Series | PIC18J (PIC® 18J family) |
| Program Memory (Flash) | 64 KB (32K x 16) |
| RAM | 3.9 KB (3936 bytes) |
| Maximum CPU Frequency | 48 MHz (8 MIPS / 16 MIPS depending on clock mode) |
| Supply Voltage | 2.0 V to 3.6 V |
| I/O Pins | 54 |
| Package | 64-pin TQFP (PT) 10 x 10 mm |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (Industrial, "I") |
| USB | USB 2.0 Full-Speed (12 Mbit/s), Device/Host/OTG, on-chip transceiver |
| Serial Interfaces | MI2C/SMBus, SPI (up to 10 Mbit/s), EUSART (LIN-capable async), FS-USB |
| ADC | 10-bit |
| Power Management | nanoWatt with multiple low-power sleep modes |
| Self-Programmable Flash | Yes (ICSP) |
| RoHS Status | Compliant |
PIC18F66J50T-I/PT Pin Configuration
| Pin 1 | RC2 — Digital I/O / PWM / Comparator output |
| Pin 2 | RC3 — Digital I/O / SPI SCK |
| Pin 3 | RC4 — Digital I/O / USB D- |
| Pin 4 | RC5 — Digital I/O / USB D+ |
| Pin 5 | RC6 — Digital I/O / EUSART TX |
| Pin 6 | RC7 — Digital I/O / EUSART RX |
| Pin 7 | RD0 — Digital I/O / PSP data |
| Pin 8 | RD1 — Digital I/O / PSP data |
| Pin 9 | RD2 — Digital I/O / PSP data |
| Pin 10 | RD3 — Digital I/O / PSP data |
| Pin 11 | VUSB — Internal USB 3.3V LDO output, decouple 0.47 uF |
| Pin 12 | VDD — Digital supply voltage (2.0 V to 3.6 V) |
| Pin 13 | VSS — Digital ground reference |
| Pin 14 | RB0 — Digital I/O / INT0 external interrupt |
| Pin 15 | RB1 — Digital I/O / INT1 external interrupt |
| Pin 16 | RB2 — Digital I/O / INT2 external interrupt |
| Pin 17 | RB3 — Digital I/O / INT3 external interrupt |
| Pin 18 | RB4 — Digital I/O / IOC |
| Pin 19 | RB5 — Digital I/O / IOC / PMD |
| Pin 20 | RB6 — Digital I/O / PGC (ICSP clock) |
| Pin 21 | RB7 — Digital I/O / PGD (ICSP data) |
| Pin 22 | RA0 — Digital I/O / analog AN0 |
| Pin 23 | RA1 — Digital I/O / analog AN1 |
| Pin 24 | RA2 — Digital I/O / analog AN2 |
| Pin 25 | RA3 — Digital I/O / analog AN3 / VREF+ |
| Pin 26 | RA4 — Digital I/O / analog AN4 |
| Pin 27 | RA5 — Digital I/O / analog AN5 / HLVDIN |
| Pin 28 | VSS — Digital ground reference |
| Pin 29 | VDD — Digital supply voltage (2.0 V to 3.6 V) |
| Pin 30 | OSC1 — Crystal/clock input |
| Pin 31 | OSC2 — Crystal/clock output |
| Pin 32 | RE0 — Digital I/O / PSP RD |
| Pin 33 | RE1 — Digital I/O / PSP WR |
| Pin 34 | RE2 — Digital I/O / PSP CS |
| Pin 35 | RE3 — Digital I/O |
| Pin 36 | RE4 — Digital I/O |
| Pin 37 | RE5 — Digital I/O |
| Pin 38 | RE6 — Digital I/O |
| Pin 39 | RE7 — Digital I/O |
| Pin 40 | AVDD — Analog supply voltage |
| Pin 41 | AVSS — Analog ground reference |
| Pin 42 | RF0 — Digital I/O / analog AN6 |
| Pin 43 | RF1 — Digital I/O / analog AN7 |
| Pin 44 | RF2 — Digital I/O / analog AN8 |
| Pin 45 | RF3 — Digital I/O / analog AN9 |
| Pin 46 | RF4 — Digital I/O / analog AN10 |
| Pin 47 | RF5 — Digital I/O / analog AN11 |
| Pin 48 | RF6 — Digital I/O / analog AN12 |
| Pin 49 | RF7 — Digital I/O / analog AN13 |
| Pin 50 | RG0 — Digital I/O |
| Pin 51 | RG1 — Digital I/O |
| Pin 52 | RG2 — Digital I/O |
| Pin 53 | RG3 — Digital I/O |
| Pin 54 | RG4 — Digital I/O |
| Pin 55 | RG5 — Digital I/O |
| Pin 56 | RG6 — Digital I/O |
| Pin 57 | RG7 — Digital I/O |
| Pin 58 | RH0 — Digital I/O |
| Pin 59 | RH1 — Digital I/O |
| Pin 60 | RH2 — Digital I/O |
| Pin 61 | RH3 — Digital I/O |
| Pin 62 | RH4 — Digital I/O |
| Pin 63 | RH5 — Digital I/O |
| Pin 64 | RH6 — Digital I/O |
Typical Applications
PIC18F66J50T-I/PT is suitable for 6 applications: USB HID Input Devices, USB-to-UART Bridge, Industrial Data Logger with USB Dump, Embedded USB Host (Printer/Barcode), Point-of-Sale Terminal / Kiosk Node, Automotive LIN Body Controller.
USB HID Input Devices
The PIC18F66J50T-I/PT's on-chip USB 2.0 Full-Speed SIE and 48 MHz PIC18J core make it a natural fit for USB Human Interface Devices such as keyboards, mice, game controllers, and custom HID peripherals. With 64 KB Flash it accommodates full HID descriptor stacks plus application logic, while 3.9 KB RAM handles HID report buffers. The on-chip transceiver eliminates external USB PHY parts, shrinking BOM. Use a 12 MHz crystal tied to the USB module for jitter-free signaling, and connect the upstream port through the dedicated D+/D- pins.
Recommended
USB-to-UART Bridge
For CDC virtual COM port bridges the PIC18F66J50T-I/PT offers native USB plus an EUSART that can drive RS-232/RS-485 transceivers. The 48 MHz core supports sustained 115200 bps and beyond with full-speed USB bulk transfers. 64 KB Flash holds the CDC class driver and any manufacturer-specific protocol extensions, while nanoWatt sleep modes cut idle current when the host suspends the bus. Decouple VUSB with 0.47 uF and follow Microchip's USB hardware checklist for EMI.
Recommended
Industrial Data Logger with USB Dump
The 3.9 KB RAM, 10-bit ADC and Full-Speed USB make PIC18F66J50T-I/PT ideal for small industrial data loggers that store sensor samples in RAM and periodically dump over USB. SPI up to 10 Mbit/s interfaces to external Flash or FRAM for non-volatile logs, and the LIN-capable EUSART can read sensor data from automotive/LIN sub-buses. The industrial -40 C to +85 C rating covers shop-floor environments, and 54 I/O pins tolerate numerous analog and digital sensors on one board.
Recommended
Embedded USB Host (Printer/Barcode)
The PIC18F66J50T-I/PT supports USB host mode, enabling low-cost embedded hosts for printers, barcode scanners, or mass-storage devices. With 48 MHz CPU and 64 KB Flash it runs Microchip's USB host stack plus class drivers. The 54 I/O pins provide LCD/keypad interfaces, while the LIN-capable EUSART or SPI talks to wireless modules. The part runs from 2.0 V to 3.6 V, allowing single-cell Li-ion designs with USB-powered charging paths.
Recommended
Point-of-Sale Terminal / Kiosk Node
The PIC18F66J50T-I/PT suits POS terminals and self-service kiosks that need USB device connectivity plus multiple serial peripherals for mag-stripe readers, NFC modules, and thermal printers. Its 48 MHz core and 64 KB Flash handle USB plus multiple UART/SPI transactions concurrently. nanoWatt power-down modes cut idle consumption between transactions, and the 64-pin TQFP exposes enough I/O for keypad scanning and LCD drive. Industrial temperature range supports semi-outdoor kiosk enclosures.
Recommended
Automotive LIN Body Controller
The LIN-capable EUSART on PIC18F66J50T-I/PT enables LIN slave nodes for body electronics such as mirror controllers, seat modules, or roof consoles. The 48 MHz core handles LIN 2.x scheduling, while 64 KB Flash stores the LIN descriptor and diagnostic services. The USB interface allows factory firmware update via a service tool without an extra programmer. Industrial -40 C to +85 C range covers cabin environments; for under-hood use consider AEC-Q100 qualified PIC18 K-series alternatives.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66J50T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F66J50-I/PT | PIC18F66J55-I/PT | PIC18F65J50T-I/PT | PIC18F66J15T-I/PT | PIC18F67J50T-I/PT |
|---|---|---|---|---|---|---|
| Package | TQFP-64 (PT) | TQFP-64 (PT) - same | TQFP-64 (PT) - same | TQFP-64 (PT) - same | TQFP-64 (PT) - same | TQFP-64 (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Program Memory | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| RAM | 3.9 KB | 3.9 KB | 3.9 KB | 3.9 KB | 3.9 KB | 3.9 KB |
| Maximum CPU Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| USB Interface | USB 2.0 FS with on-chip transceiver | USB 2.0 FS with on-chip transceiver | USB 2.0 FS with on-chip transceiver | USB 2.0 FS with on-chip transceiver | No USB peripheral | USB 2.0 FS with on-chip transceiver |
| I/O Pins | 54 | 54 | 54 | 53 | 54 | 54 |
| Supply Voltage | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V |
| 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 |
| On-chip Crypto Engine | No | No | Yes | No | No | No |
Key Differentiators
- On-chip USB 2.0 Full-Speed transceiver eliminates external PHY (vs PIC18F66J15T-I/PT)
- Highest I/O count in the PIC18J 64-pin TQFP family (vs PIC18F65J50T-I/PT)
- Broader peripheral set than lower-cost PIC18F variants (vs PIC18F4550-I/P)
Design Notes
Decouple VUSB (pin 11) with a 0.47 uF ceramic capacitor placed within 5 mm of the pin, per Microchip's USB hardware checklist. VDD/AVDD should each have 100 nF plus 10 uF bulk ceramic. Avoid tying AVDD and VDD together on the supply side without a ferrite bead if the ADC accuracy at >10 kHz sample rates matters.
Route the USB D+/D- pair as a 90-ohm differential with matched length and keep them clear of clock traces. Place the 12 MHz crystal (or resonator) within 5 mm of OSC1/OSC2 with a guard ring tied to GND. Use a four-layer PCB with continuous ground plane under the TQFP for thermal dissipation and EMI.
Do not omit the VUSB 0.47 uF decoupling capacitor - USB enumeration will fail without it. When migrating firmware from non-J PIC18 (PIC18F4550 etc.), update SFR names because the 18J family uses slightly different register layouts. Confirm the CONFIG bits for oscillator mode and WDT before first programming; a wrong FOSC setting bricks USB clocking silently.
Compliance Information
RoHS and lead-free per Microchip product page. PIC18F66J50T-I/PT is not AEC-Q100 qualified; for automotive use evaluate PIC18F25K80 or other K-series qualified parts.
