PIC18LF45J50-I/PT - 8-bit USB MCU, 32KB Flash, 44-TQFP | Microchip
MPN: PIC18LF45J50-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.45 | $5.45 |
| 10 | $4.9 | $49.00 |
| 100 | $4.35 | $435.00 |
| 500 | $3.8 | $1,900.00 |
| 1,000 | $3.3 | $3,300.00 |
| 3,000 | $2.85 | $8,550.00 |
PIC18LF45J50-I/PT Overview
An 8-bit microcontroller (MCU) is a small, self-contained computer-on-a-chip that integrates a CPU, RAM, non-volatile program memory, and peripheral interfaces on a single die. PIC microcontrollers use a Harvard RISC architecture with separate program and data buses, which allows the CPU to fetch an instruction and a data operand in the same cycle. The PIC18 family extends the baseline PIC16 instruction set with C-friendly addressing, a hardware multiplier, and 16-bit instruction words, positioning PIC18LF45J50-I/PT inside the broader hierarchy of 8-bit MCU -> PIC microcontroller -> Microchip MCU portfolio -> embedded computing platform.
Key features include 32 KB self-programmable Flash, 3.8 KB RAM, full-speed USB 2.0 with on-chip transceiver, 13-channel 10-bit ADC, two analog comparators, two UART/SPI/I2C modules, and nanoWatt XLP deep-sleep modes. The device supports 34 digital I/O pins, 2 CCP modules, and an Enhanced Capture/Compare/PWM peripheral for motor and lighting control. Real-Time Clock/Calendar with software-calibrated 32 kHz source is also integrated.
Architecturally, the PIC18LF45J50-I/PT pairs the standard PIC18 pipeline with a wide operating voltage range, an internal 31 kHz to 8 MHz oscillator block, and a 4x PLL to reach 48 MHz. The on-chip USB SIE handles full-speed and low-speed signaling without an external PHY, while nanoWatt XLP technology gates unused peripherals to achieve the 13 nA sleep figure, which is critical for battery-powered USB peripherals.
Typical applications include USB HID peripherals (keyboards, mice, joysticks), battery-powered sensors, industrial data loggers, USB-to-UART bridges, and low-power embedded control nodes. The wide temperature range (-40C to +85C industrial grade) also suits factory automation modules and consumer-electronics accessories.
When designing with this part, place the 12 MHz external crystal or use the internal 8 MHz HFINTOSC with 4x PLL close to the OSC pins, keep D+/D- trace lengths matched within 50 mil, and follow Microchip's "PIC18F46J50 Family Data Sheet" guidelines for USB-IF compliance testing.
This page synthesizes distributor pricing, same-family drop-in alternatives, USB design notes, and a 44-pin TQFP pinout diagram that are not co-located on any single manufacturer or distributor page.
Drop-in alternatives for PIC18LF45J50-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 PIC18LF45J50-I/PT (same form factor and footprint) — differing in ADC, Core, Package, MSL Level, Operating Temperature.
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PIC18LF45J50-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit Harvard RISC) |
| Family | PIC18 J-series XLP nanoWatt |
| Program Memory | 32 KB Flash |
| Data RAM | 3.8 KB |
| Max CPU Speed | 48 MHz (12 MIPS) |
| Supply Voltage | 2.0 V to 3.6 V |
| Deep-Sleep Current | 13 nA typical (nanoWatt XLP) |
| USB | USB 2.0 Full-Speed / Low-Speed, on-chip transceiver |
| Digital I/O Pins | 34 |
| ADC | 13-channel, 10-bit |
| Comparators | 2 analog comparators |
| Timers | Timer0/1/2/3 + 2 CCP + ECCP |
| Communication | 2x EUSART, 2x MSSP (SPI/I2C) |
| Package | 44-pin TQFP (PT) 10x10 mm |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
PIC18LF45J50-I/PT Pin Configuration
| Pin 1 | /MCLR/RE3 — Master Clear (reset) input, or digital input RE3 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / ADC VREF+ |
| Pin 6 | RA4/AN4/T0CKI — PORTA bit 4 / analog input 4 / Timer0 clock |
| Pin 7 | RA5/AN5/SS1 — PORTA bit 5 / analog input 5 / SPI1 slave-select |
| Pin 8 | RE0/RD — PORTE bit 0 / Parallel Slave Port read control |
| Pin 9 | RE1/WR — PORTE bit 1 / Parallel Slave Port write control |
| Pin 10 | RE2/CS — PORTE bit 2 / Parallel Slave Port chip-select |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground |
| Pin 13 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock input |
| Pin 14 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / Enhanced CCP1 PWM output |
| Pin 18 | RC3/SCK1/SCL1 — PORTC bit 3 / SPI1 clock / I2C1 clock |
| Pin 19 | RC4/D-/VM — PORTC bit 4 / USB D- / external USB monitor input |
| Pin 20 | RC5/D+/VP — PORTC bit 5 / USB D+ / external USB monitor input |
| Pin 21 | RC6/TX1/CK1 — PORTC bit 6 / EUSART1 TX / EUSART1 clock |
| Pin 22 | RC7/RX1/DT1 — PORTC bit 7 / EUSART1 RX / EUSART1 data |
| Pin 23 | RB0/AN12 — PORTB bit 0 / analog input 12 / interrupt-on-change |
| Pin 24 | RB1/AN10 — PORTB bit 1 / analog input 10 / interrupt-on-change |
| Pin 25 | RB2/AN8 — PORTB bit 2 / analog input 8 / interrupt-on-change |
| Pin 26 | RB3/AN9 — PORTB bit 3 / analog input 9 / interrupt-on-change |
| Pin 27 | RB4/AN11 — PORTB bit 4 / analog input 11 / interrupt-on-change |
| Pin 28 | RB5/AN13 — PORTB bit 5 / analog input 13 / interrupt-on-change |
| Pin 29 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 30 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 31 | VUSB — USB internal transceiver supply (3.3 V regulated output) |
| Pin 32 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port data bit 0 |
| Pin 33 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port data bit 1 |
| Pin 34 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port data bit 2 |
| Pin 35 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port data bit 3 |
| Pin 36 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port data bit 4 |
| Pin 37 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port data bit 5 |
| Pin 38 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port data bit 6 |
| Pin 39 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port data bit 7 |
| Pin 40 | VSS — Ground |
| Pin 41 | VDD — Positive supply voltage |
| Pin 42 | ENVREG — Internal voltage regulator enable (tie to VDD for 3.3 V USB) |
| Pin 43 | VCAP — Internal regulator output filter capacitor |
| Pin 44 | RF7/SS2 — PORTF bit 7 / SPI2 slave-select |
Typical Applications
PIC18LF45J50-I/PT is suitable for 6 applications: USB HID Peripherals (Keyboard, Mouse, Joystick), USB-to-UART Bridge Module, Battery-Powered Sensor Data Logger, Industrial USB Sensor Hub, USB-Connected Audio Control Surface, Low-Cost USB Bootloader Host Probe.
USB HID Peripherals (Keyboard, Mouse, Joystick)
The PIC18LF45J50-I/PT is a near-ideal core for USB Human Interface Devices thanks to its on-chip USB 2.0 full-speed transceiver and 12 MIPS CPU. A typical HID keyboard uses 12 KB to 18 KB of Flash for the HID report descriptors plus class driver, well within the 32 KB available; the 48 MHz clock yields the 1 ms USB polling interval with comfortable timing margin. The 13 nA deep-sleep current allows battery-powered wireless keyboard dongles to last multiple years on a coin cell. Pair the MCU with an external 2.4 GHz radio (e.g., nRF24L01) and an EEPROM HID descriptor store for a complete HID solution.
Recommended
USB-to-UART Bridge Module
The PIC18LF45J50-I/PT's integrated USB transceiver and dual EUSART make it an excellent CDC-class USB-to-UART bridge, replacing FTDI FT232R solutions at lower BOM cost. Operating at 48 MHz, the device achieves 921600 bps UART throughput with no flow-control overrun thanks to the on-chip 16-byte hardware FIFO. The wide 2.0 V to 3.6 V supply matches industrial 3.3 V logic rails without level shifters. Use Microchip's CDC bootloader to allow field firmware upgrades over USB without an external programmer.
Recommended
Battery-Powered Sensor Data Logger
The PIC18LF45J50-I/PT's nanoWatt XLP technology with 13 nA deep-sleep current enables multi-year battery operation in remote sensor data loggers. The 13-channel 10-bit ADC directly digitizes analog sensors without an external ADC, while 3.8 KB RAM buffers samples between USB service intervals. The on-chip RTCC with software-calibrated 32 kHz source timestamps each measurement. Typical use case: deploy a logger reading temperature, humidity, and battery voltage, then service once per year by retrieving over USB.
Recommended
Industrial USB Sensor Hub
In factory automation, the PIC18LF45J50-I/PT aggregates multiple serial sensors and exposes them to a host PC over USB. Two EUSARTs plus two MSSP (SPI/I2C) channels allow connection of up to four sensor buses simultaneously, while the 48 MHz CPU sustains USB full-speed traffic and sensor polling concurrently. The -40 C to +85 C industrial temperature range satisfies factory-floor environments. The 44-pin TQFP package supports standard IPC-9701 SMT reflow profiles.
Recommended
USB-Connected Audio Control Surface
Hobbyist and prosumer audio mixers can use the PIC18LF45J50-I/PT as a USB-HID knob-and-slider controller, sending MIDI Control Change or HID Volume messages. The PWM + ECCP module drives LED VU meters and indicator brightness; the 13-channel ADC reads potentiometer and fader positions. 32 KB Flash holds USB-MIDI stack plus custom HID descriptor logic. Compared with the PIC16F1455, this part provides more headroom for software-driven user interfaces.
Recommended
Low-Cost USB Bootloader Host Probe
Field engineers use the PIC18LF45J50-I/PT as a USB-host-capable firmware-update dongle for legacy PIC targets. By implementing Microchip's AN1310 HID bootloader, the MCU streams new HEX files to target MCUs over USB and triggers a reset for self-programming. The 34 digital I/O pins drive status LEDs and target RESET/DTR lines. Wide 2.0 V to 3.6 V supply allows the dongle to be powered from any USB-A port without external regulation concerns.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF45J50-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF45J50T-I/PT | PIC18F45J50-I/PT | PIC18LF46J50-I/PT | PIC18LF44J50-I/PT | PIC18F45J50T-I/PT | PIC18LF46J50T-I/PT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (PT) 10x10 mm | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same |
| Core | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC |
| Flash Memory | 32 KB | 32 KB | 32 KB | 64 KB | 16 KB | 32 KB | 64 KB |
| Data RAM | 3.8 KB | 3.8 KB | 3.8 KB | 3.8 KB | 3.8 KB | 3.8 KB | 3.8 KB |
| Max CPU Speed | 48 MHz (12 MIPS) | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| USB | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed | USB 2.0 Full/Low-Speed |
| 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 | 2.0 V to 3.6 V |
| Deep-Sleep Current | 13 nA | 13 nA | 13 nA | 13 nA | 13 nA | 13 nA | 13 nA |
| Digital I/O | 34 | 34 | 34 | 34 | 34 | 34 | 34 |
Key Differentiators
- On-chip USB 2.0 full-speed transceiver eliminates external PHY cost (vs PIC16F877A-I/P)
- nanoWatt XLP deep-sleep current of 13 nA extends coin-cell battery life by years (vs PIC18F2550-I/SP)
- Drop-in upgrade path to 64 KB Flash without PCB redesign (vs PIC18LF45J10-I/PT)
Design Notes
USB-IF compliance requires matched 90 ohm differential impedance on the D+/D- pair and a 15 kohm pull-down resistor on each line, per USB 2.0 specification section 6.2. According to Microchip's PIC18F46J50 family datasheet, the trace length mismatch between D+ and D- must stay below 4 mm. Place the VUSB 0.1 uF bypass capacitor within 3 mm of pin 31 and the VCAP 10 uF capacitor within 5 mm of pin 43 to ensure regulator stability. A common-mode choke (e.g., ACM2012) is recommended near the USB connector for EMI compliance.
Estimated: at 48 MHz CPU + active USB + 5 mA peripheral load, the PIC18LF45J50-I/PT draws approximately 25 mA typical. To maximize battery life, set the CPU to IDLE via the SLEEP instruction between USB SOF interrupts and use the RTCC + WDT wake source to achieve the 13 nA deep-sleep figure. Decouple VDD pins 11 and 41 individually with 100 nF ceramic capacitors and a bulk 10 uF aluminum-polymer capacitor to handle USB inrush current at hot-plug events.
Do not leave the ENVREG pin (pin 42) floating; tie it to VDD to enable the internal 3.3 V regulator that supplies the USB transceiver. Forgetting this is the most common reason for USB enumeration failure on first prototypes. Also, the ICSP pins RB6/PGD (pin 29) and RB7/PGC (pin 30) must not be pulled low at power-up to avoid entering programming mode unintentionally. Use 4.7 kohm pull-ups to VDD on these pins, and add a series 100 ohm resistor on each to the ICSP header for in-circuit programming protection.
Compliance Information
RoHS compliant and lead-free per Microchip product page and DigiKey compliance data. Not AEC-Q100 qualified - for automotive USB applications, choose PIC18F46J50 or other AEC-Q100-qualified Microchip variants.