PIC18LF45J50-I/ML - 8-Bit USB MCU, 32KB Flash, 44-QFN | Microchip
MPN: PIC18LF45J50-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.1 | $6.10 |
| 10 | $5.55 | $55.50 |
| 100 | $4.85 | $485.00 |
| 500 | $4.2 | $2,100.00 |
| 1,000 | $3.75 | $3,750.00 |
PIC18LF45J50-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and a configurable set of peripheral blocks (I/O, timers, communications, ADC) into one package. The PIC18LF45J50-I/ML sits in the sub-hierarchy: microcontroller -> 8-bit MCU -> PIC18 family -> PIC18 J-series (USB) -> power-managed (LF / nanoWatt XLP) variants. The 8-bit PIC18 core uses an enhanced Harvard RISC architecture with a 16-bit instruction word, which gives higher code density than 8-bit instruction word cores while keeping the silicon footprint small.
Key features of this part include 32 KB (16K x 16) of self-programmable Flash, 4 KB RAM, a 10-channel 10-bit ADC, two analog comparators, two CCP/ECCP modules, two USART, two MSSP (I2C/SPI), a Full-Speed USB 2.0 device/host/OTG transceiver with on-chip pull-ups, up to 32 mA source/sink on I/O, and nanoWatt XLP power management that drops quiescent current to roughly <100 nA in Sleep with RTCC. The 44-QFN-EP package offers a small 8x8 mm footprint and a thermal pad for better dissipation in space-constrained USB dongles.
Typical applications are Full-Speed USB peripherals, USB-to-UART bridges, USB HID/CDC devices, low-power battery sensors, and small industrial control nodes where the integrated USB PHY saves an external chip. The exposed pad on the QFN-EP package must be soldered to the ground plane for both electrical grounding and thermal dissipation.
When designing with this part, place the 12 MHz crystal or resonator and its load capacitors within a few millimetres of the OSC1/OSC2 pins to avoid noise coupling into the USB PLL, and follow Microchip's USB 2.0 stack guidelines (impedance-controlled 90 ohm differential D+/D- traces, common-mode choke) to pass USB compliance. The LF prefix means the part uses the lower-voltage process; do not power it above 3.6 V or you will damage the device.
This page synthesises verified distributor pricing, drop-in same-package alternatives, and practical design notes for the PIC18LF45J50-I/ML that are not bundled together in the manufacturer datasheet, giving procurement and firmware engineers a single reference point for sourcing and substitution decisions.
Drop-in alternatives for PIC18LF45J50-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 PIC18LF45J50-I/ML (same form factor and footprint) — differing in ADC, Package, Operating Temperature, Core, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F45J50-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF46J50-I/ML
✅ Drop-In✓ In Stock
$3.75 / Unit
View Datasheet →PIC18F46J50-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F46J50-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF45J50-I/ML Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit) Enhanced Harvard RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| Data Memory (RAM) | 4 KB |
| Maximum CPU Speed | 48 MHz (12 MIPS) |
| Supply Voltage (VDD) | 2.0 V to 3.6 V |
| Operating Temperature | -40C to +85C (Industrial, -I) |
| Package | 44-pin QFN-EP (8x8 mm) with exposed pad |
| USB Controller | USB 2.0 Full-Speed (12 Mbps) device/host/OTG, on-chip transceiver |
| ADC | 10 channels, 10-bit, 1.1 Msps |
| Comparators | 2 analog comparators |
| CCP / ECCP Modules | 2 (1 CCP + 1 ECCP) |
| UART | 2x EUSART |
| I2C / SPI (MSSP) | 2x MSSP (I2C + SPI) |
| Timers | 4x 8/16-bit (Timer0..Timer3) |
| I/O Pins | Up to 32 digital I/O |
| I/O Sink/Source | 25 mA / 25 mA per pin |
| Power-Saving Modes | nanoWatt XLP: Sleep, Idle, RTCC; <100 nA Sleep with RTCC (typical) |
| Programming | ICSP (In-Circuit Serial Programming), self-programmable Flash |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18LF45J50-I/ML Pin Configuration
| Pin 1 | EP — Exposed thermal pad (must be soldered to GND plane) |
| Pin 2 | RA0/AN0 — Digital I/O / analog input 0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / analog input 3 / ADC VREF+ |
| Pin 6 | RA4 — Digital I/O (open-drain option) |
| Pin 7 | RA5/AN4 — Digital I/O / analog input 4 |
| Pin 8 | RA6/OSC2/CLKO — Digital I/O / crystal output / clock output |
| Pin 9 | RA7/OSC1/CLKI — Digital I/O / crystal input / clock input |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage 2.0-3.6 V |
| Pin 12 | RB0/AN12 — Digital I/O / analog input 12 / INT0 |
| Pin 13 | RB1/AN10 — Digital I/O / analog input 10 / INT1 |
| Pin 14 | RB2/AN8 — Digital I/O / analog input 8 / INT2 |
| Pin 15 | RB3/AN9 — Digital I/O / analog input 9 / INT3 |
| Pin 16 | RB4/AN11 — Digital I/O / analog input 11 |
| Pin 17 | RB5/AN13 — Digital I/O / analog input 13 |
| Pin 18 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 19 | RB7/PGD — Digital I/O / ICSP data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply voltage 2.0-3.6 V |
| Pin 22 | RC0 — Digital I/O |
| Pin 23 | RC1 — Digital I/O |
| Pin 24 | D- — USB Full-Speed D- differential data line |
| Pin 25 | D+ — USB Full-Speed D+ differential data line |
| Pin 26 | VUSB — USB 3.3 V regulator output (connect to 220 nF bypass) |
| Pin 27 | RC2 — Digital I/O |
| Pin 28 | RC3 — Digital I/O |
| Pin 29 | RC4 — Digital I/O |
| Pin 30 | RC5 — Digital I/O |
| Pin 31 | RC6 — Digital I/O / EUSART1 TX |
| Pin 32 | RC7 — Digital I/O / EUSART1 RX |
| Pin 33 | RD0 — Digital I/O |
| Pin 34 | RD1 — Digital I/O |
| Pin 35 | RD2 — Digital I/O |
| Pin 36 | RD3 — Digital I/O |
| Pin 37 | RD4 — Digital I/O |
| Pin 38 | RD5 — Digital I/O |
| Pin 39 | RD6 — Digital I/O |
| Pin 40 | RD7 — Digital I/O |
| Pin 41 | RE0 — Digital I/O |
| Pin 42 | RE1 — Digital I/O |
| Pin 43 | RE2 — Digital I/O |
| Pin 44 | MCLR/RE3 — Reset (active-low) / digital I/O |
Typical Applications
PIC18LF45J50-I/ML is suitable for 6 applications: USB-to-UART Bridge Dongle, USB HID Input Device, Low-Power Battery Sensor Node, Industrial Data Logger, USB CDC Virtual COM Port Device, USB Host Mass Storage Bridge.
USB-to-UART Bridge Dongle
The PIC18LF45J50-I/ML's integrated USB 2.0 Full-Speed transceiver, dual EUSART, and 32 KB Flash make it a natural fit for USB-to-UART bridge dongles that replace legacy RS-232 cables. The LF 2.0-3.6 V VDD range lets the MCU draw directly from the USB 3.3 V regulated rail without additional level shifting. Engineers typically load the Microchip CDC ACM stack and run the UART at up to 921600 bps through the EUSART block, while 4 KB RAM comfortably holds line buffers and protocol state. The 44-QFN-EP (8x8 mm) keeps the PCB small enough to fit inside a USB Type-A connector shell, and the exposed thermal pad handles the modest 250 mW continuous dissipation of an active USB device.
Recommended
USB HID Input Device
The PIC18LF45J50-I/ML is widely used in custom USB HID peripherals such as barcode scanners, foot pedals, and industrial keypads. The on-chip USB Full-Speed transceiver with internal pull-up resistor eliminates external USB components, and 32 KB Flash is enough to host the Microchip USB HID stack plus custom report descriptors. The 10-channel 10-bit ADC scans up to ten buttons or rotary encoders, while the two CCP/ECCP modules drive LED feedback with hardware PWM. With nanoWat XLP Sleep current below 100 nA, the device is ideal for battery-powered HID scanners that must wake on a button press through the IOC interrupt-on-change module.
Recommended
Low-Power Battery Sensor Node
Engineers building wireless battery sensor nodes pair the PIC18LF45J50-I/ML with a sub-GHz radio for periodic environmental sensing. The LF process and nanoWatt XLP technology deliver Sleep-mode current below 100 nA with RTCC, while the 2.0-3.6 V VDD range accepts two AA alkaline cells directly without a boost regulator. The 48 MHz CPU wakes in microseconds to execute measurement routines, sample 10-bit ADC channels, and transmit data via SPI through the MSSP block before returning to Sleep. The on-chip comparator triggers wake-up on sensor threshold crossing without CPU intervention, conserving battery life for multi-year deployments.
Recommended
Industrial Data Logger
For industrial data loggers that store process telemetry to removable media, the PIC18LF45J50-I/ML offers 32 KB Flash for firmware plus an MSSP block that drives an external SPI Flash or SD card over an SPI channel. The 10-channel 10-bit ADC captures thermocouple-conditioned or 4-20 mA loop signals at up to 1.1 Msps, and the two EUSART blocks interface to RS-485 transceivers for plant-network connectivity. The industrial -40C to +85C operating range and 2.0-3.6 V supply make the part tolerant of factory power rails that swing during motor inrush, while the exposed thermal pad allows sustained write traffic to external memory without thermal throttling.
Recommended
USB CDC Virtual COM Port Device
The PIC18LF45J50-I/ML is commonly deployed in CDC ACM Virtual COM Port designs that emulate RS-232 over USB for legacy test equipment. The integrated Full-Speed USB transceiver supports up to 12 Mbps with bulk transfers, and 4 KB RAM accommodates the CDC stack alongside a 256-byte line buffer for sustained throughput. Developers leverage the Microchip MLA USB library to bring up CDC mode in days, and the active-high enable pin on the EUSART provides hardware flow control to the host. The 44-QFN-EP package fits behind a USB Type-B connector on the back panel of test gear, where its exposed pad grounds to the chassis shield for EMI immunity.
Recommended
USB Host Mass Storage Bridge
Host-mode operation on the PIC18LF45J50-I/ML enables a USB thumb-drive-to-SPI bridge, useful for field firmware updates of headless industrial controllers. The internal USB transceiver supports both device and host/OTG roles, and the MSSP block talks to an SD card or external SPI Flash for local caching. The 32 KB Flash hosts the Microchip USB Host stack plus a FAT12/16 file-system module, while 4 KB RAM holds sector buffers during USB transfers. Powered from a 3.3 V LDO off the industrial 24 V bus, the device draws less than 30 mA even during active host enumeration, and the exposed pad keeps junction temperature well within the industrial -40C to +85C range.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF45J50-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F45J50-I/ML | PIC18LF46J50-I/ML | PIC18F46J50-I/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN-EP (8x8 mm) | 44-QFN-EP (8x8 mm) - same | 44-QFN-EP (8x8 mm) - same | 44-QFN-EP (8x8 mm) - same |
| Process / VDD Range | LF / 2.0-3.6 V | F / 2.0-3.3 V + 5 V-tolerant I/O | LF / 2.0-3.6 V | F / 2.0-3.3 V + 5 V-tolerant I/O |
| Flash | 32 KB | 32 KB (0%) | 64 KB (+100%) | 64 KB (+100%) |
| RAM | 4 KB | 4 KB (0%) | 4 KB (0%) | 4 KB (0%) |
| Maximum CPU Speed | 48 MHz (12 MIPS) | 48 MHz (0%) | 48 MHz (0%) | 48 MHz (0%) |
| USB Controller | USB 2.0 Full-Speed on-chip transceiver | USB 2.0 Full-Speed on-chip transceiver | USB 2.0 Full-Speed on-chip transceiver | USB 2.0 Full-Speed on-chip transceiver |
| I/O Pin Count | Up to 32 | Up to 32 | Up to 32 | Up to 32 |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- On-chip USB 2.0 Full-Speed transceiver with internal pull-up (vs PIC18F2550-I/SP)
- nanoWatt XLP Sleep current below 100 nA with RTCC (vs PIC18F45K50-I/ML)
- 48 MHz PIC18 J-family core with 16-bit instruction (vs PIC18LF4523-I/ML)
Design Notes
The PIC18LF45J50-I/ML runs on a 2.0-3.6 V VDD rail and draws roughly 9 mA at 48 MHz with all peripherals active; in nanoWatt XLP Sleep with RTCC enabled, quiescent current drops below 100 nA. Add a 100 nF decoupling cap within 5 mm of every VDD pin and a bulk 4.7 uF tantalum close to the regulator output. For USB designs, VUSB (pin 26) needs its own 220 nF ceramic bypass and an internal 3.3 V regulator that powers the USB transceiver during bus activity.
Route D+ and D- as a 90 ohm differential pair with continuous ground reference on the layer beneath, keep them matched within 150 mil length delta, and avoid sharp 90-degree bends. Place the 12 MHz crystal or resonator within 5 mm of pins 30/31 (OSC1/OSC2), with grounded guard traces to suppress noise injection into the USB PLL. The QFN exposed pad (pin 1) must be soldered to a continuous ground pour with at least 8 thermal vias for both grounding and dissipation.
Do not exceed VDD = 3.6 V on the LF process variant - the PIC18F45J50-I/ML is required when 5 V-tolerant I/O is mandatory. ICSP programming on PGC/PGD (RB6/RB7) requires a 4.7 kohm pull-up on MCLR for in-circuit programming reliability; leaving MCLR floating prevents reset entry. Do not connect D+/D- to legacy 5 V USB transceivers - the internal PIC18 USB block is 3.3 V only and requires a level shifter for 5 V hosts.
Compliance Information
RoHS and REACH compliant per Microchip product declarations. Not AEC-Q100 qualified - choose a Q1 or AEC-Q100 designated part for automotive. Lead-free and halogen-free assembly is supported; reflow profile per JEDEC J-STD-020 MSL classifications.
