PIC18LF55K42-E/PT - 32KB Flash 8-bit MCU, 48-TQFP-EP | Microchip
MPN: PIC18LF55K42-E/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.92 | $29.20 |
| 100 | $2.61 | $261.00 |
| 500 | $2.35 | $1,175.00 |
| 1,000 | $2.1 | $2,100.00 |
PIC18LF55K42-E/PT Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip built around an 8-bit data bus. It sits within the broader hierarchy of microcontrollers -> embedded processors -> integrated circuits -> semiconductors. The PIC18 family specifically targets high-performance 8-bit applications requiring C-friendly architecture, hardware DMA, and rich peripheral integration. Low-power 'LF' variants like this one extend operating voltage down to 1.8V for battery-powered designs, where XLP (eXtreme Low Power) technology enables nanoWatt sleep currents.
Key features of the PIC18LF55K42-E/PT include 64 MHz maximum CPU clock, 44 configurable I/O pins, an integrated 12-bit ADC2 with computation, hardware DMA for memory-to-memory and memory-to-peripheral transfers, multiple communication peripherals (I2C, SPI, UART/USART), and enhanced PWM with complementary outputs. The -E temperature grade extends operation from -40C to +125C for industrial and harsh-environment applications.
The PIC18 core employs a Harvard architecture with a 16-bit instruction word and 8-bit data path, providing C-friendly addressing and deterministic interrupt latency. Core-independent peripherals such as the CWG (Complementary Waveform Generator), NCO (Numerically Controlled Oscillator), and hardware DMA offload the CPU, allowing complex control loops to run without software intervention. The MAP memory scheme provides separate boot and secure flash regions for bootloader and IP protection.
Typical applications for the PIC18LF55K42-E/PT include industrial sensor nodes, motor control (BLDC and stepper), IoT edge devices, LED lighting controllers, consumer appliance control, and battery-powered instrumentation. The 32KB flash and DMA support make it suitable for protocol stacks such as Modbus, LIN, and basic BLE bridging when paired with an external radio.
When designing with this device, pay attention to decoupling (place 100nF + 1uF near VDD pins), unused-pin tie-off (drive or pull per datasheet), and ICP/ICD programming pin allocation. The 'LF' variant requires VDD between 1.8V and 3.6V, so an LDO or buck converter is required for 5V systems.
This page synthesizes distributor stock data, drop-in compatible alternatives, and practical design notes not found in a single manufacturer datasheet view.
Drop-in alternatives for PIC18LF55K42-E/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 PIC18LF55K42-E/PT (same form factor and footprint) — differing in DAC, Core Architecture, DMA, Operating Temperature Range, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF56K42-E/PT
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC18F55K42-E/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF45K42-E/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18LF55K42-E/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit Harvard) |
| Program Memory (Flash) | 32 KB (16K x 16) |
| Data SRAM | 2 KB |
| EEPROM | 256 B |
| Maximum CPU Clock | 64 MHz |
| ADC | 12-bit ADC2 with computation |
| DAC | Yes (on-chip) |
| Number of I/O Pins | 44 |
| Operating Supply Voltage | 1.8 V to 3.6 V |
| Operating Temperature Range | -40 C to +125 C (E grade) |
| Package | 48-TQFP-EP (7x7 mm) |
| Mounting Type | Surface Mount |
| Communication Interfaces | I2C, SPI, UART/USART |
| DMA | Yes (hardware) |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Low-Power Technology | XLP (eXtreme Low Power) |
PIC18LF55K42-E/PT Pin Configuration
| Pin 1 | RE3/MCLR — Master Clear (reset) input, also RE3 GPIO |
| Pin 2 | RA0 — PORTA bit 0 / analog input |
| Pin 3 | RA1 — PORTA bit 1 / analog input |
| Pin 4 | RA2 — PORTA bit 2 / analog input |
| Pin 5 | RA3 — PORTA bit 3 / analog input |
| Pin 6 | RA4 — PORTA bit 4 / analog input |
| Pin 7 | RA5 — PORTA bit 5 / analog input |
| Pin 8 | RA6 — PORTA bit 6 / analog input |
| Pin 9 | RA7 — PORTA bit 7 / analog input |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply (1.8V-3.6V) |
| Pin 12 | RB0 — PORTB bit 0 / analog / IOC |
| Pin 13 | RB1 — PORTB bit 1 / analog / IOC |
| Pin 14 | RB2 — PORTB bit 2 / analog / IOC |
| Pin 15 | RB3 — PORTB bit 3 / analog / IOC |
| Pin 16 | RB4 — PORTB bit 4 / analog / IOC |
| Pin 17 | RB5 — PORTB bit 5 / analog / IOC |
| Pin 18 | RB6 — PORTB bit 6 / ICSPCLK |
| Pin 19 | RB7 — PORTB bit 7 / ICSPDAT |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply (1.8V-3.6V) |
| Pin 22 | RC0 — PORTC bit 0 / analog |
| Pin 23 | RC1 — PORTC bit 1 / analog |
| Pin 24 | RC2 — PORTC bit 2 / analog |
| Pin 25 | RC3 — PORTC bit 3 / analog |
| Pin 26 | RC4 — PORTC bit 4 / analog |
| Pin 27 | RC5 — PORTC bit 5 / analog |
| Pin 28 | RC6 — PORTC bit 6 / analog |
| Pin 29 | RC7 — PORTC bit 7 / analog |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply (1.8V-3.6V) |
| Pin 32 | RD0 — PORTD bit 0 / analog |
| Pin 33 | RD1 — PORTD bit 1 / analog |
| Pin 34 | RD2 — PORTD bit 2 / analog |
| Pin 35 | RD3 — PORTD bit 3 / analog |
| Pin 36 | RD4 — PORTD bit 4 / analog |
| Pin 37 | RD5 — PORTD bit 5 / analog |
| Pin 38 | RD6 — PORTD bit 6 / analog |
| Pin 39 | RD7 — PORTD bit 7 / analog |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply (1.8V-3.6V) |
| Pin 42 | RF0 — PORTF bit 0 / analog |
| Pin 43 | RF1 — PORTF bit 1 / analog |
| Pin 44 | RF2 — PORTF bit 2 / analog |
| Pin 45 | RF3 — PORTF bit 3 / analog |
| Pin 46 | RF4 — PORTF bit 4 / analog |
| Pin 47 | RF5 — PORTF bit 5 / analog |
| Pin 48 | RF6 — PORTF bit 6 / analog |
Typical Applications
PIC18LF55K42-E/PT is suitable for 6 applications: BLDC Motor Control, Industrial Sensor Node, Battery-Powered IoT Edge Device, LED Lighting Controller, Consumer Appliance Control, Automotive Body Electronics (Non-Safety).
BLDC Motor Control
The PIC18LF55K42-E/PT is well matched to BLDC and PMSM motor control in compact 3.3V systems. The integrated Complementary Waveform Generator (CWG) provides hardware dead-band generation, the 12-bit ADC2 samples back-EMF at high speed, and the DMA engine offloads sample timing from the CPU. With 64 MHz core clock and CIPs (Core Independent Peripherals), the MCU can run sensorless FOC at 4-8 kHz switching frequency. Its XLP features minimize sleep current during standby. Pair it with a gate driver like MCP8021 or MCP8022 for a compact 3-phase inverter; the 48-TQFP-EP package dissipates ~1W at full CPU load without external heatsinking.
Recommended
Industrial Sensor Node
For distributed industrial sensing (4-20mA loops, RTD/thermocouple conditioning, Modbus nodes), the PIC18LF55K42-E/PT provides ample headroom with 32 KB flash for Modbus RTU stacks and 2 KB RAM for buffer handling. The 12-bit ADC2 with computation performs oversampling and averaging in hardware, freeing CPU cycles. Multiple UART channels enable RS-485 Modbus master/slave topologies. Hardware DMA supports continuous ADC-to-RAM transfers without CPU intervention. The -E temperature grade (-40C to +125C) supports outdoor and cabinet-mounted deployments. Operating from 1.8V to 3.6V it interfaces directly to modern low-power sensors and LoRaWAN modules.
Recommended
Battery-Powered IoT Edge Device
XLP (eXtreme Low Power) features make the PIC18LF55K42-E/PT ideal for battery-powered IoT edge nodes running from 1.8V to 3.6V. Sleep currents in the nanoWatt range extend coin-cell life to multiple years. The integrated DMA, ADC2 with computation, and UART peripherals enable event-driven wake/sleep cycles with no CPU involvement for routine sampling. The 32 KB flash accommodates LoRaWAN or BLE-bridging protocol stacks. Hardware AES (in some K42 variants) provides secure communication, and the MAP memory scheme enables secure bootloaders for OTA firmware updates. Recommended for smart locks, asset trackers, and wireless sensor modules.
Recommended
LED Lighting Controller
The PIC18LF55K42-E/PT drives multi-channel LED lighting systems using its 16-bit PWM with complementary outputs and CWG for half-bridge topology. Each PWM channel supports independent duty and dead-band control, enabling smooth color mixing and dimming. Hardware DMA synchronizes PWM updates to avoid flicker, and the 12-bit DAC provides analog reference for tunable-white or constant-current drivers. The -40 to +125C operating range suits indoor and outdoor luminaires. With 32 KB flash, the MCU supports DALI, DMX, or 0-10V dimming protocols alongside safety diagnostics (thermal foldback, open-LED detection).
Recommended
Consumer Appliance Control
Washing machines, dishwashers, coffee makers, and small kitchen appliances benefit from the PIC18LF55K42-E/PT's blend of 32 KB flash, motor-control PWM, and rich communication peripherals. The MCU drives user-interface displays (LEDs, character LCDs) while managing BLDC pumps, valves, and heaters via PWM and ADC feedback loops. CIPs handle safety-critical timing (overcurrent, overtemperature) independently of the CPU. The wide operating voltage (1.8-3.6V) simplifies supply design from a rectified 3.3V rail. The 48-TQFP-EP provides a low-profile footprint for slim appliance form factors.
Recommended
Automotive Body Electronics (Non-Safety)
For non-safety automotive body applications such as seat controllers, mirror adjusters, ambient lighting, and HVAC flap motors, the PIC18LF55K42-E/PT offers 44 I/O, LIN bus support, and the -E temperature grade (-40C to +125C). The PIC18F55K42 variant supports 5V I/O levels required by automotive bus standards, while this LF variant suits 3.3V subsystems. Multiple PWM channels drive small brushed DC motors, and the DMA engine handles communication buffer management for LIN frames. Note: this part is not AEC-Q100 qualified; use PIC18F55K42 with AEC-Q100 documentation for production automotive programs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF55K42-E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF56K42-E/PT | PIC18F55K42-E/PT | PIC18LF45K42-E/PT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-TQFP-EP (7x7 mm) | 48-TQFP-EP (7x7 mm) - same | 48-TQFP-EP (7x7 mm) - same | 48-TQFP-EP (7x7 mm) - same |
| Program Memory (Flash) | 32 KB | 48 KB (+50%) | 32 KB (same) | 32 KB (same) |
| Data SRAM | 2 KB | 4 KB (+100%) | 2 KB (same) | 2 KB (same) |
| Operating Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 2.3 V to 5.5 V | 1.8 V to 3.6 V |
| Maximum CPU Clock | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| I/O Pins | 44 | 44 | 44 | 44 (subset used, 40-pin die) |
| Temperature Grade | -40C to +125C (E) | -40C to +125C (E) | -40C to +125C (E) | -40C to +125C (E) |
| Low-Power (XLP) | Yes | Yes | Yes | Yes |
Key Differentiators
- 32 KB flash at 64 MHz with DMA and CIPs (vs PIC18LF46K22-E/MV)
- XLP nanoWatt sleep with 1.8V minimum VDD (vs PIC18F55K42-E/PT)
- 12-bit ADC2 with computation (vs PIC18LF47K40-I/PT)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to each VDD/VSS pair (5 pairs total on this 48-pin TQFP-EP). Add one bulk 1 uF to 10 uF capacitor near the highest-current VDD pin to handle transient load steps when peripherals switch. The 'LF' variant operates down to 1.8 V, so verify that your LDO maintains regulation at the MCU's peak Iq (typically 15 mA active at 64 MHz). For battery applications, MCP1700 LDO adds only 1.6 uA quiescent overhead.
Route ICSPDAT and ICSPCLK (RB6/RB7) to a 2x5 0.1-inch header for in-circuit serial programming and debugging. Place the programming header near the MCU with no series resistors or buffers in line, and add ESD protection diodes if the connector is user-accessible. The exposed thermal pad (EP) on the TQFP package should be soldered to a grounded copper pour to improve thermal dissipation and mechanical stability, even though the LF variant dissipates minimal power.
Do not apply 5 V signals to any I/O pin when VDD is below 3.0 V - the PIC18LF55K42's I/O are 5V-tolerant only when VDD >= 3V. For 3.3V designs interfacing to 5V peripherals, use a level translator like the TXS0108E. Always configure unused I/O pins as outputs driving low to minimize sleep current and prevent floating-input oscillations. The MCLR pin must be pulled high through a 10 kohm resistor unless external reset control is intended.
Compliance Information
RoHS compliant per Microchip product page. Industrial -E temperature grade (-40C to +125C). NOT AEC-Q100 qualified; for automotive safety applications use PIC18F55K42 with AEC-Q100 documentation. Lead-free and halogen-free per Microchip declaration.
