PIC18F45J50T-I/ML - 48MHz USB MCU 32KB Flash 44-QFN | Microchip
MPN: PIC18F45J50T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.62 | $4.62 |
| 10 | $4.18 | $41.80 |
| 100 | $3.74 | $374.00 |
| 500 | $3.41 | $1,705.00 |
| 1,000 | $3.05 | $3,050.00 |
PIC18F45J50T-I/ML Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), working memory (RAM), and peripheral interfaces (UART, I/O, ADC, USB). It belongs to the broader class of embedded processors, sitting below microprocessors (which require external memory) but above simple state machines. The PIC18F45J50 specifically uses the enhanced PIC18 Harvard architecture with a 16-bit program word and 8-bit data path, optimized for deterministic real-time control.
Key features of this part include a full-speed USB 2.0 device/host/OTG transceiver on-chip, 36 digital I/O pins, a 10-bit ADC with up to 13 input channels, two analog comparators, two UART/USART ports, two MSSP (SPI/I2C) modules, and nanoWatt XLP deep-sleep current as low as 13 nA typical. The 44-QFN exposed-pad package provides excellent thermal performance in a compact 8x8 mm footprint.
Typical applications include USB peripherals (HID, CDC, MSD, audio class), industrial sensor hubs, low-power data loggers, and consumer devices requiring USB connectivity without an external transceiver. The integrated USB PHY saves BOM cost and PCB area compared to MCUs that need an external USB interface chip.
When designing with this device, pay attention to the 3.3V-only operation: the PIC18F45J50 family requires VDD between 2.0V and 3.6V, which means most 5V systems need a level shifter or a separate 3.3V rail. The exposed pad (EP) must be soldered to the ground plane for proper thermal dissipation and electrical performance.
This page synthesizes distributor pricing, drop-in alternative MPNs, and engineering design notes not found in the manufacturer datasheet, helping procurement and embedded engineers make a confident part selection.
Drop-in alternatives for PIC18F45J50T-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 PIC18F45J50T-I/ML (same form factor and footprint) — differing in ADC, Package, Core Architecture, Operating Temperature, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45J50-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F46J50T-I/ML
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC18F47J53T-I/ML
✅ Drop-In✓ In Stock
$3.95 / Unit
View Datasheet →PIC18F45J11T-I/ML
✅ Drop-In✓ In Stock
$3.2 / Unit
View Datasheet →PIC18F45J50T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit Harvard) |
| Program Memory Type | Flash |
| Program Memory Size | 32 KB (16K x 16) |
| RAM Size | 3.8 KB |
| Maximum CPU Frequency | 48 MHz |
| Supply Voltage (VDD) | 2.0 V to 3.6 V |
| I/O Pins | 36 |
| Package | 44-QFN (8x8 mm) with exposed pad |
| USB Interface | USB 2.0 Full-Speed device/host/OTG, on-chip transceiver |
| ADC | 10-bit, up to 13 channels |
| UART/USART | 2 |
| SPI (MSSP) | 2 |
| I2C (MSSP) | 2 |
| Analog Comparators | 2 |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Power-Saving Mode | nanoWatt XLP (Deep Sleep ~13 nA typical) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F45J50T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC VREF- |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 5 | RA5/AN4 — PORTA bit 5 / Analog input 4 |
| Pin 6 | RA6/OSC2 — PORTA bit 6 / Oscillator output |
| Pin 7 | RA7/OSC1 — PORTA bit 7 / Oscillator input |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 10 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 11 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 12 | RB3/INT3 — PORTB bit 3 / External interrupt 3 |
| Pin 13 | RB4 — PORTB bit 4 |
| Pin 14 | VDD — Positive supply (2.0V to 3.6V) |
| Pin 15 | RB5 — PORTB bit 5 |
| Pin 16 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 17 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 18 | RC0 — PORTC bit 0 |
| Pin 19 | RC1 — PORTC bit 1 |
| Pin 20 | RC2 — PORTC bit 2 |
| Pin 21 | RC3 — PORTC bit 3 |
| Pin 22 | RC4 — PORTC bit 4 |
| Pin 23 | RC5 — PORTC bit 5 |
| Pin 24 | RC6 — PORTC bit 6 |
| Pin 25 | RC7 — PORTC bit 7 |
| Pin 26 | RD0 — PORTD bit 0 |
| Pin 27 | RD1 — PORTD bit 1 |
| Pin 28 | RD2 — PORTD bit 2 |
| Pin 29 | RD3 — PORTD bit 3 |
| Pin 30 | RD4 — PORTD bit 4 |
| Pin 31 | RD5 — PORTD bit 5 |
| Pin 32 | RD6 — PORTD bit 6 |
| Pin 33 | RD7 — PORTD bit 7 |
| Pin 34 | RE0 — PORTE bit 0 |
| Pin 35 | RE1 — PORTE bit 1 |
| Pin 36 | RE2 — PORTE bit 2 |
| Pin 37 | RE3 — PORTE bit 3 |
| Pin 38 | VDDCORE — Internal regulator output (decouple with cap) |
| Pin 39 | VSS — Ground reference |
| Pin 40 | D- — USB D- line |
| Pin 41 | D+ — USB D+ line |
| Pin 42 | VBUS — USB VBUS sense input |
| Pin 43 | VUSB — USB internal regulator output (decouple) |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | EP — Exposed thermal pad - solder to ground plane |
Typical Applications
PIC18F45J50T-I/ML is suitable for 7 applications: USB HID / CDC Peripherals, Industrial Sensor Hubs and Data Loggers, USB Audio Class Devices, Low-Power Wearable / Battery Devices, USB Mass Storage / MSD Readers, USB-Based Programming / Bootloader Hosts, Consumer USB Toys and Educational Devices.
USB HID / CDC Peripherals
The PIC18F45J50T-I/ML is purpose-built for USB peripherals thanks to its integrated full-speed USB 2.0 device/host/OTG transceiver. The 48 MHz CPU delivers 16 MIPS, enough to handle HID class descriptors, CDC serial emulation, or custom vendor requests without an external PHY or 24 MHz USB crystal - saving roughly $0.40 and 4x4 mm of PCB area. Its 32KB Flash comfortably fits the Microchip USB stack, custom descriptors, and application code for keyboards, mice, and serial adapters.
Recommended
Industrial Sensor Hubs and Data Loggers
The PIC18F45J50T-I/ML fits industrial sensor hubs by combining a 10-bit ADC with 13 channels, 36 I/O pins for multiple sensor interfaces, and nanoWatt XLP deep-sleep under 50 nA for battery-backed installations. The 32KB Flash supports custom Modbus or proprietary protocol stacks, and 3.8KB RAM is ample for buffering samples before USB transfers. The 44-QFN exposed pad enables PCB thermal performance in sealed industrial enclosures.
Recommended
USB Audio Class Devices
The PIC18F45J50T-I/ML can serve USB audio class 1.0 devices (headsets, speakers, microphones) because the integrated USB transceiver supports isochronous transfers at the required 1-ms frame rate. The 48 MHz CPU drives 16 MIPS - sufficient for audio sample buffering and basic DSP. The PIC18F46J50T-I/ML upgrade provides 64KB Flash needed for larger audio descriptor tables and bulk streaming pipelines in production designs.
Recommended
Low-Power Wearable / Battery Devices
The PIC18F45J50T-I/ML suits battery-powered wearables thanks to nanoWatt XLP deep-sleep current under 50 nA and 6 configurable idle/sleep modes that scale CPU peripherals with application demand. Industrial -40C to +85C operation handles cold-weather wearables. The integrated USB enables in-system battery charging and firmware updates without an external programmer, which is critical for sealed wearable products.
Recommended
USB Mass Storage / MSD Readers
The PIC18F45J50T-I/ML is a popular MCU for USB mass-storage class card readers interfacing SD cards, eMMC, or NOR Flash to a host PC. The integrated USB 2.0 full-speed supports 12 Mbps transfers - fast enough for bulk card-reader throughput. The 36 I/O pins expose the SPI bus needed for SD card communication, and 3.8KB RAM buffers the small file-system scratch data the MCU needs.
Recommended
USB-Based Programming / Bootloader Hosts
Production-line programmers use the PIC18F45J50T-I/ML as a USB host controller that flashes other PIC MCUs via ICSP. The USB host mode and 48 MHz CPU let the J50 act as a stand-alone programmer dongle - no PC tool needed beyond a USB host port. The 44-QFN compact footprint fits easily inside a programmer pen-style enclosure.
Recommended
Consumer USB Toys and Educational Devices
The PIC18F45J50T-I/ML is widely used in USB toys and educational microcontroller kits (such as Microchip's own Low Pin Count USB Development Kit) because its integrated USB PHY eliminates the 24 MHz crystal requirement and shrinks the BOM. The 32KB Flash is large enough for hobbyist USB stacks, and the 8-bit PIC18 instruction set is approachable for beginners learning USB enumeration and HID class design.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F45J50T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45J50-I/ML | PIC18F46J50T-I/ML | PIC18F44J50T-I/PT | PIC18F47J53T-I/ML | PIC18F45J11T-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (8x8 mm) | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-TQFP - different | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same |
| Core / Architecture | 8-bit PIC18 | 8-bit PIC18 | 8-bit PIC18 | 8-bit PIC18 | 8-bit PIC18 | 8-bit PIC18 |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Flash Memory | 32 KB | 32 KB | 64 KB | 16 KB | 128 KB | 32 KB |
| RAM | 3.8 KB | 3.8 KB | 4.2 KB | 2.0 KB | 8 KB | 3.8 KB |
| USB Transceiver | On-chip USB 2.0 FS | On-chip USB 2.0 FS | On-chip USB 2.0 FS | On-chip USB 2.0 FS | On-chip USB 2.0 FS | No integrated USB |
| ADC Resolution | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 12-bit, 13 channels | 10-bit, 13 channels |
| I/O Pins | 36 | 36 | 36 | 36 | 36 | 36 |
Key Differentiators
- Integrated USB 2.0 full-speed transceiver with no external crystal required (vs PIC18F45J11T-I/ML)
- Double the Flash and additional RAM for upgrade-in-place flexibility (vs PIC18F45J50-I/ML (same silicon))
- Industrial-grade -40C to +85C operating range for harsh environments (vs PIC18F45J11T-I/ML)
Design Notes
Estimated: At VDD=3.3V and CPU running at full 48 MHz with USB active, core current draw is approximately 15-20 mA. Adding USB enumeration plus active peripherals, plan for 30 mA total worst-case. The on-chip 3.3V regulator (VDDCORE pin) requires a 10 uF decoupling cap; do not power external loads from VDDCORE. For battery designs, use the nanoWatt XLP sleep modes (Deep Sleep ~13 nA typical) aggressively - wake on RB0 interrupt or WDT rather than polling.
Estimated: At 30 mA total current and 3.3V supply, the chip dissipates approximately 100 mW. The 44-QFN exposed pad provides theta_JA around 28 C/W on a 4-layer 1oz PCB, giving ~2.8 C junction rise - well within the 85 C industrial limit. For best thermal performance, stitch the EP to a continuous ground pour with at least 16 thermal vias. Never leave the EP floating; this affects electrical grounding as well as thermal dissipation.
Route the USB D+/D- lines as a 90-ohm differential pair with matched length and continuous ground plane underneath. Place the VUSB decoupling capacitor (typically 220 nF) as close to pin 43 as possible. Keep the 24 MHz USB clock traces short and guarded; if not using an external crystal, the internal USB PLL uses the HFINTOSC and accuracy may impact USB compliance. For 5V-only systems, add a level shifter or a 3.3V LDO for VDD.
Common pitfalls: (1) Exceeding 3.6V on any I/O pin will damage the part - this is NOT a 5V-tolerant PIC18. (2) Forgetting to solder the exposed pad causes thermal and electrical issues. (3) Using RB6/RB7 as regular GPIO disables ICSP - reserve these for programming. (4) When migrating from PIC18F4455 to PIC18F45J50, note the J50 requires 3.3V only, while the F4455 supports 5V operation. (5) USB host mode requires external 5V VBUS supply - the J50 does not provide it.
When using the MSSP modules in SPI mode at 48 MHz (Fosc/4 = 12 MHz SCLK), keep SPI traces under 50 mm and add 22-33 ohm series resistors on clock and data lines for dampening. I2C lines need 4.7k-10k pull-ups to VDD; the J50 has no internal I2C pull-ups on PORTB/C. For analog signals to the 10-bit ADC, place a 100 nF cap on the AVSS/AVDD pins and use guard traces around sensitive analog inputs to avoid switching noise from USB or SPI clocks coupling into measurements.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade (I suffix) but NOT AEC-Q100 qualified for automotive applications. Conflict-minerals statement available from Microchip corporate compliance.
