PIC18LF4455T-I/ML - 48MHz USB MCU 24KB Flash | Microchip
MPN: PIC18LF4455T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.2 | $72.00 |
| 100 | $6.45 | $645.00 |
| 500 | $5.8 | $2,900.00 |
| 1,000 | $5.2 | $5,200.00 |
PIC18LF4455T-I/ML Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash), volatile data memory (RAM), and a rich set of peripherals on a single silicon die. Within the broader taxonomy, the PIC18F family sits between Microchip's baseline PIC10/12/16 families and the higher-end PIC24/dsPIC families, targeting USB connectivity, mixed-signal embedded control, and human-interface designs. The 'LF' prefix denotes the wide-voltage F-variant core that operates across 2.0 V to 5.5 V, enabling direct Li-ion battery operation and supporting Microchip's nanoWatt power-saving modes.
Key features include three serial communication ports (FS-USB 2.0 at 12 Mbit/s, I2C/SPI up to 10 Mbit/s, and an EUSART LIN-capable asynchronous port), 10-bit ADC with up to 13 channels, two capture/compare/PWM modules, and nanoWatt Technology for sleep currents down to nanoampere levels. The 44-pin QFN exposed pad provides a low thermal resistance path suitable for sustained full-speed USB operation without external heatsinking.
The device uses Microchip's enhanced Harvard RISC architecture with a hardware multiplier and 16-bit instructions optimized for C-compiled code. The wide operating voltage window (2.0 V to 5.5 V) means the same firmware image can target both USB-powered 5 V designs and battery-powered 3.3 V or 2.5 V designs, reducing BOM variants.
Typical applications include USB human-interface devices (HID) such as keyboards, mice, and game controllers; USB-to-UART bridges and CDC-class peripherals; embedded data loggers with USB mass storage; industrial sensor interfaces; and consumer electronics that require USB connectivity. The combination of FS-USB and nanoWatt low-power modes also makes the part suitable for USB-powered battery chargers.
When designing with this part, ensure the exposed pad is soldered to a sufficiently large ground pour to maintain junction temperature within the -40 C to +85 C industrial range. The internal 48 MHz PLL drives the USB module; firmware must enable the PLL and wait for PLL lock before USB enumeration to avoid USB bus errors.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not available on the manufacturer datasheet, helping procurement and engineering teams evaluate the PIC18LF4455T-I/ML for new designs and re-spins.
Drop-in alternatives for PIC18LF4455T-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 PIC18LF4455T-I/ML (same form factor and footprint) — differing in Operating Temperature, Package, Core Architecture, Timers, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4550T-I/ML
✅ Drop-In✓ In Stock
$3.28 / Unit
View Datasheet →PIC18LF4450T-I/ML
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC18LF4455-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3 / Unit
View Datasheet →PIC18F4455T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4455T-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (enhanced Harvard) |
| Family | PIC18F (PIC18LF4455 device) |
| Program Memory (Flash) | 24 KB (12K x 16) |
| Data RAM | 2048 bytes |
| Maximum CPU Clock | 48 MHz (12 MIPS) |
| Operating Voltage | 2.0 V to 5.5 V |
| USB Module | Full-Speed USB 2.0 (12 Mbit/s) |
| Serial Interfaces | USB, I2C, SPI (up to 10 Mbit/s), EUSART (LIN-capable) |
| ADC | 10-bit, up to 13 channels |
| PWM / CCP Modules | 2 CCP |
| Package | 44-pin QFN (8x8 mm) with exposed pad (ML) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (Industrial, 'I') |
| Low-Power Feature | nanoWatt Technology |
| RoHS Status | Compliant |
PIC18LF4455T-I/ML Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input / Programming voltage / Digital input only on port E bit 3 |
| Pin 2 | RA0/AN0 — Digital I/O on port A bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O on port A bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF-/CVREF — Digital I/O on port A bit 2 / Analog input channel 2 / DAC negative reference / Comparator voltage reference output |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O on port A bit 3 / Analog input channel 3 / DAC positive reference |
| Pin 6 | RA4/T0CKI/C1OUT — Digital I/O on port A bit 4 / Timer 0 clock input / Comparator 1 output |
| Pin 7 | RA5/AN4/SS/HLVDIN/C2OUT — Digital I/O on port A bit 5 / Analog input channel 4 / SPI slave select / High/Low-Voltage Detect input / Comparator 2 output |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — External oscillator input / External clock input / Digital I/O on port A bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — External oscillator output / Clock output / Digital I/O on port A bit 6 |
| Pin 11 | RC0/T1OSO/T13CKI — Digital I/O on port C bit 0 / Timer 1 oscillator output / Timer1/Timer3 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — Digital I/O on port C bit 1 / Timer 1 oscillator input / Capture/Compare/PWM 2 |
| Pin 13 | RC2/CCP1 — Digital I/O on port C bit 2 / Capture/Compare/PWM 1 |
| Pin 14 | VUSB — Internal USB 3.3 V regulator output (bypass to VSS with capacitor) |
| Pin 15 | RC4/D-/VM — Digital I/O on port C bit 4 / USB D- line / External USB transceiver VMODE input |
| Pin 16 | RC5/D+/VP — Digital I/O on port C bit 5 / USB D+ line / External USB transceiver VPOE input |
| Pin 17 | RC6/TX/CK — Digital I/O on port C bit 6 / EUSART asynchronous transmit / EUSART synchronous clock |
| Pin 18 | RC7/RX/DT/SDO — Digital I/O on port C bit 7 / EUSART asynchronous receive / EUSART synchronous data / SPI data out |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | RB0/AN12/INT0/FLT0/SDI/SDA — Digital I/O on port B bit 0 / Analog input channel 12 / External interrupt 0 / PWM fault input / SPI data in / I2C data |
| Pin 22 | RB1/AN10/INT1/SCK/SCL — Digital I/O on port B bit 1 / Analog input channel 10 / External interrupt 1 / SPI clock / I2C clock |
| Pin 23 | RB2/AN8/INT2/VMO — Digital I/O on port B bit 2 / Analog input channel 8 / External interrupt 2 / External USB transceiver VMO output |
| Pin 24 | RB3/AN9/CCP2/VPO — Digital I/O on port B bit 3 / Analog input channel 9 / Capture/Compare/PWM 2 / External USB transceiver VPO output |
| Pin 25 | RB4/AN11/KBI0 — Digital I/O on port B bit 4 / Analog input channel 11 / Interrupt-on-change bit 0 |
| Pin 26 | RB5/KBI1/PGM — Digital I/O on port B bit 5 / Interrupt-on-change bit 1 / Low-Voltage Programming input |
| Pin 27 | RB6/KBI2/PGC — Digital I/O on port B bit 6 / Interrupt-on-change bit 2 / In-Circuit Debugger clock |
| Pin 28 | RB7/KBI3/PGD — Digital I/O on port B bit 7 / Interrupt-on-change bit 3 / In-Circuit Debugger data |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | RD0/SPP0 — Digital I/O on port D bit 0 / Streaming Parallel Port data bit 0 |
| Pin 32 | RD1/SPP1 — Digital I/O on port D bit 1 / Streaming Parallel Port data bit 1 |
| Pin 33 | RD2/SPP2 — Digital I/O on port D bit 2 / Streaming Parallel Port data bit 2 |
| Pin 34 | RD3/SPP3 — Digital I/O on port D bit 3 / Streaming Parallel Port data bit 3 |
| Pin 35 | RD4/SPP4 — Digital I/O on port D bit 4 / Streaming Parallel Port data bit 4 |
| Pin 36 | RD5/SPP5/P1B — Digital I/O on port D bit 5 / Streaming Parallel Port data bit 5 / Enhanced PWM output 1B |
| Pin 37 | RD6/SPP6/P1C — Digital I/O on port D bit 6 / Streaming Parallel Port data bit 6 / Enhanced PWM output 1C |
| Pin 38 | RD7/SPP7/P1D — Digital I/O on port D bit 7 / Streaming Parallel Port data bit 7 / Enhanced PWM output 1D |
| Pin 39 | VSS — Ground reference |
| Pin 40 | VDD — Positive supply voltage |
| Pin 41 | RE0/AN5/CK1SPP — Digital I/O on port E bit 0 / Analog input channel 5 / SPP clock 1 |
| Pin 42 | RE1/AN6/CK2SPP — Digital I/O on port E bit 1 / Analog input channel 6 / SPP clock 2 |
| Pin 43 | RE2/AN7/OESPP — Digital I/O on port E bit 2 / Analog input channel 7 / SPP output enable |
| Pin 44 | VDD — Positive supply voltage |
Typical Applications
PIC18LF4455T-I/ML is suitable for 7 applications: USB HID Peripherals (Keyboard/Mouse/Gamepad), USB-to-UART CDC Bridge, USB Mass Storage Data Logger, Industrial USB Sensor Interface, Consumer USB Audio / MIDI Device, USB-Powered Battery Charger, USB-Connected Embedded Bootloader Host.
USB HID Peripherals (Keyboard/Mouse/Gamepad)
The PIC18LF4455T-I/ML is an ideal MCU for USB Human Interface Device (HID) class peripherals such as keyboards, mice, game controllers, and remote controls, because its integrated Full-Speed USB 2.0 SIE eliminates the need for an external USB PHY and reduces BOM cost. With 24 KB of Flash the device fits Microchip's free USB HID stack plus typical HID report descriptors and scan-matrix firmware, while 2048 bytes of RAM comfortably holds HID reports, debounce state, and the USB endpoint buffers. The 48 MHz CPU clock delivers the 12 MIPS required for low-latency USB polling without dropping packets. Designers place the part with the D+/D- pins routed as a 90 ohm differential pair directly to the USB connector, and the wide 2.0 V to 5.5 V supply range supports both bus-powered and self-powered HID devices.
Recommended
USB-to-UART CDC Bridge
The PIC18LF4455T-I/ML serves as a cost-effective USB-to-UART CDC bridge, leveraging its integrated FS-USB peripheral and hardware EUSART to expose a virtual COM port over USB without an external FTDI or CP210x bridge IC. The 24 KB Flash holds the CDC class driver plus buffering logic, while the 48 MHz core sustains 921600 bps UART throughput alongside USB 12 Mbit/s traffic. Operating from 2.0 V to 5.5 V means the same firmware image can drive 3.3 V MCUs and 5 V legacy UART devices through a single design. Typical implementation uses the on-chip SPI or I2C for EEPROM-based configuration storage, with nanoWatt sleep modes reducing idle current when the host suspends the USB bus.
Recommended
USB Mass Storage Data Logger
The PIC18LF4455T-I/ML fits portable USB mass-storage data loggers that record sensor data to an SD card or external Flash and present it to the host as a removable drive. The Full-Speed USB module combined with the hardware SPI port (up to 10 Mbit/s) provides a deterministic interface to SD cards, and the 10-bit ADC with up to 13 channels captures analog sensor inputs at the rates needed for environmental, vibration, or biometric logging. The 24 KB Flash fits the Mass Storage class driver plus FAT file-system glue, while 2048 bytes of RAM buffers USB sector transfers. The wide voltage range supports operation from a single 18650 Li-ion cell with on-board boost regulation, and the exposed-pad QFN package keeps the die temperature low during sustained logging.
Recommended
Industrial USB Sensor Interface
The PIC18LF4455T-I/ML is well suited to industrial USB sensor-interface modules that digitize analog signals from strain gauges, thermocouples, or process-control transducers and present the data to a host PC over USB. The 10-bit ADC (up to 13 channels) captures sensor signals, while the I2C and SPI peripherals connect to external 16-/24-bit ADCs or DACs when higher resolution is required. The -40 C to +85 C industrial temperature range allows deployment in factory-floor enclosures, and the wide 2.0 V to 5.5 V supply accommodates 24 V industrial bus rails after regulation. The EUSART module supports LIN-bus slave communication for automotive and industrial sensor networks, while the FS-USB peripheral enables simultaneous host-side configuration.
Recommended
Consumer USB Audio / MIDI Device
The PIC18LF4455T-I/ML powers low-cost consumer USB audio and MIDI peripherals such as MIDI controllers, USB microphones, and simple USB speakers, where the integrated FS-USB SIE handles isochronous or interrupt transfers without external codec glue. The 48 MHz core delivers the throughput needed for full-speed isochronous audio frames at 48 kHz mono, and the SPI peripheral connects to external audio DACs and ADCs. With 24 KB Flash the device fits the USB Audio class driver plus MIDI stream parsing, while 2048 bytes of RAM accommodates USB endpoint buffers and audio sample queues. The wide operating voltage lets the same PCB serve both 5 V USB-bus-powered and 3.3 V battery-powered consumer devices.
Recommended
USB-Powered Battery Charger
The PIC18LF4455T-I/ML is an effective controller for USB-powered Li-ion or NiMH battery charger modules, combining the FS-USB peripheral for host-side enumeration and current negotiation with on-chip PWM/CCP modules for switch-mode charger regulation. The wide 2.0 V to 5.5 V supply means the part can directly monitor cell voltage on a single Li-ion cell while simultaneously communicating with the USB host. The 10-bit ADC measures charge current, battery voltage, and temperature thermistor inputs at the rates needed for CC/CV charge profiling. nanoWatt Technology keeps standby current in the microamp range when the host suspends the USB bus, extending shelf life of battery-equipped peripherals.
Recommended
USB-Connected Embedded Bootloader Host
The PIC18LF4455T-I/ML serves as a USB-connected bootloader host for production-line firmware programming of downstream PIC microcontrollers, leveraging FS-USB for command exchange with the PC and SPI/I2C for in-system programming of target MCUs. The 24 KB Flash accommodates a dual-image bootloader with rollback support, and the 2048 bytes of RAM provides the buffering required for USB command frames plus ISP packet assembly. The 48 MHz CPU executes USB stack plus ICSP/ICSPIO bit-banging without dropping USB frames. The exposed-pad 44-pin QFN package allows the design to fit inside the chassis of a bench-top programming fixture, and the wide voltage range supports both 3.3 V and 5 V target MCUs through level-shifters on the programming header.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4455T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4550T-I/ML | PIC18LF4450T-I/ML | PIC18LF4455-I/ML | PIC18F4455T-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN (8x8 mm) ML | 44-pin QFN (8x8 mm) ML - same | 44-pin QFN (8x8 mm) ML - same | 44-pin QFN (8x8 mm) ML - same | 44-pin QFN (8x8 mm) ML - same |
| Flash Program Memory | 24 KB | 32 KB (+33%) | 32 KB (+33%) | 24 KB (identical) | 24 KB (identical) |
| RAM | 2048 bytes | 2048 bytes (identical) | 2048 bytes (identical) | 2048 bytes (identical) | 2048 bytes (identical) |
| Operating Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V (5 V-only) |
| USB Module | FS-USB 2.0 (12 Mbit/s) | FS-USB 2.0 (12 Mbit/s) | FS-USB 2.0 (12 Mbit/s) | FS-USB 2.0 (12 Mbit/s) | FS-USB 2.0 (12 Mbit/s) |
| Maximum CPU Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| Operating Temperature | -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 |
| Packaging | Tape & Reel (T suffix) | Tape & Reel | Tape & Reel | Tube (no T&R) | Tape & Reel |
Key Differentiators
- Wide-voltage 2.0 V to 5.5 V supply enables Li-ion and 3.3 V designs without level shifters (vs PIC18F4455T-I/ML)
- 24 KB Flash fits typical USB HID + CDC stacks with margin for application code (vs PIC18LF4450T-I/ML)
- Tape & Reel packaging ready for high-volume SMT assembly (vs PIC18LF4455-I/ML)
Design Notes
The 44-pin QFN package has a center exposed thermal pad that MUST be soldered to a PCB ground pour of at least the same size as the pad (typically ~5 mm square) to achieve the rated thermal performance. Without proper soldering, junction temperature can exceed 125 C during sustained USB enumeration, causing thermal shutdown. Use a via array (8-12 vias on 1.0 mm pitch) under the pad to conduct heat into inner ground planes. Decoupling: place one 100 nF X7R capacitor as close as possible to each VDD pin (pins 20, 30, 40, 44), and add a single 10 uF bulk tantalum or aluminum-polymer capacitor near the IC.
Route the USB D+ (RC5) and D- (RC4) lines as a 90 ohm differential pair with matched length, keeping the pair on the same PCB layer and avoiding splits or jumps between reference planes. Place a 15 kohm pull-up resistor on D+ (full-speed device indication) close to the MCU, and add 47 pF capacitors on each data line to ground near the USB connector to suppress ESD. Do not place any other signals under the D+/D- pair, and keep the pair away from switching regulator power inductors. The internal 3.3 V USB regulator (VUSB pin) requires a 220 nF bypass capacitor to ground; do not load VUSB externally beyond its rated 3.3 V / 50 mA capacity.
Estimated: USB enumeration failures on PIC18LF4455T-I/ML designs almost always trace to one of three root causes: (1) the 48 MHz PLL is not enabled in firmware before the USB module is configured - enable PLL, set CPUDIV to /2, then wait for PLL lock before USB attach; (2) the VUSB decoupling cap is missing or undersized - this causes intermittent USB resets during suspend/resume cycles; (3) the D+ pull-up is on RC4 instead of RC5 - the firmware must drive RC5 high only after PLL lock to comply with USB 2.0 attach timing. Also confirm that the I/O pins used for ICSP (RB6/PGC, RB7/PGD) are not pulled low at reset by external circuitry, or in-circuit debugging will fail.
When designing USB-bus-powered applications, the PIC18LF4455T-I/ML can be powered directly from the 5 V VBUS line, but for battery-powered designs the wide 2.0 V to 5.5 V supply range allows direct Li-ion cell operation with appropriate charge management. nanoWatt Technology reduces sleep current below 100 nA typical with the RTCC enabled, enabling multi-year standby life on small primary cells. The internal 3.3 V USB regulator is sourced from the main VDD supply, so VBUS must be gated through the device's internal comparators or external MOSFET when running from a battery to prevent reverse current back into the USB host. Always include a 4.7 uF bulk capacitor near VUSB and a 100 nF ceramic decoupling cap directly at every VDD pin.
Compliance Information
RoHS compliant per Microchip product page and distributor listings. Industrial -40 C to +85 C temperature range (I-suffix) is not AEC-Q100 automotive qualified; AEC-Q100 parts in this family use the -EQ suffix. Lead-free reflow profile per JEDEC J-STD-020.
