PIC18LF4420T-I/ML - 16KB Flash 8-bit MCU 44-QFN | Microchip
MPN: PIC18LF4420T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.92 | $5.92 |
| 10 | $5.32 | $53.20 |
| 100 | $4.74 | $474.00 |
| 500 | $4.26 | $2,130.00 |
| 1,000 | $3.79 | $3,790.00 |
PIC18LF4420T-I/ML Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and programmable peripherals. The PIC18LF architecture uses an enhanced 8-bit Harvard RISC core with a 16-bit instruction word, placing it within the broader hierarchy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. The LF prefix designates the low-voltage variant, allowing battery-powered and 3.3 V designs without efficiency loss compared to the 5 V-only F-series.
Key features include nanoWatt Technology for dynamic power management with multiple idle and sleep modes, a 10-bit successive-approximation ADC with automatic acquisition, dual analog comparators, one Enhanced Capture/Compare/PWM (ECCP) module and one CCP module, MSSP (SPI/I2C) and Enhanced USART peripherals, a 16-bit timer/counter plus two 8-bit timers, and a 13-channel 10-bit ADC. The device supports in-circuit serial programming (ICSP) and self-programming.
The PIC18LF4420 implements an enhanced Harvard architecture with separate program and data buses, a hardware multiplier, and a priority-level interrupt controller supporting both vectored and polled interrupt models. nanoWatt Technology provides INTOSC, INTOSCIO, and secondary oscillator modes for low-power operation.
Typical applications include industrial control panels, low-power sensor nodes, HVAC thermostats, portable instrumentation, and battery-powered metering devices where the LF voltage range and QFN footprint enable compact PCB layouts. The 36 I/O pins provide flexible peripheral mapping for mixed analog and digital interfaces.
When designing with this device, ensure the QFN thermal pad is soldered to a sufficient copper pour for heat dissipation, place decoupling capacitors within 5 mm of each power pin, and configure the configuration bits correctly for the chosen oscillator mode.
This page synthesizes drop-in alternatives, comparison data, and practical design notes compiled from Microchip datasheets and distributor inventories.
Drop-in alternatives for PIC18LF4420T-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 PIC18LF4420T-I/ML (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Timers, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4420-I/ML
✅ Drop-In✓ In Stock
$3.18 / Unit
View Datasheet →PIC18LF4520T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4420T-I/ML
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F46K20-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF4420T-I/ML Maximum Ratings & Electrical Characteristics
| Architecture | PIC 8-bit Harvard RISC |
| Program Memory (Flash) | 16 KB |
| Data SRAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Operating Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, 13 channels |
| Timers | 1 x 16-bit + 2 x 8-bit |
| PWM Modules | 1 ECCP + 1 CCP |
| Communication | MSSP (SPI/I2C) + Enhanced USART |
| Comparators | 2 analog comparators |
| Package | 44-pin QFN (ML) 8x8 mm |
| Operating Temperature | -40C to +85C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18LF4420T-I/ML Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input |
| Pin 2 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / Analog channel 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / Analog channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / Analog channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O / Parallel port read / Analog channel 5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O / Parallel port write / Analog channel 6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O / Parallel port chip select / Analog channel 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI/RA7 — Oscillator input / External clock / Digital I/O |
| Pin 14 | OSC2/CLKO/RA6 — Oscillator output / Clock output / Digital I/O |
| Pin 15 | RC0/T1OSO/T13CKI — Digital I/O / Timer1 oscillator output / Timer1 clock |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 18 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O / Parallel slave port data bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O / Parallel slave port data bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O / Parallel slave port data bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O / Parallel slave port data bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O / SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — Digital I/O / USART receive / USART data |
| Pin 27 | RD4/PSP4 — Digital I/O / Parallel slave port data bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O / Parallel slave port data bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O / Parallel slave port data bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O / Parallel slave port data bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT0 — Digital I/O / External interrupt 0 |
| Pin 34 | RB1/INT1 — Digital I/O / External interrupt 1 |
| Pin 35 | RB2/INT2 — Digital I/O / External interrupt 2 |
| Pin 36 | RB3/CCP2 — Digital I/O / CCP2 alternate pin |
| Pin 37 | RB4 — Digital I/O / Interrupt-on-change |
| Pin 38 | RB5 — Digital I/O / Interrupt-on-change |
| Pin 39 | RB6/PGC — Digital I/O / ICSP clock / Interrupt-on-change |
| Pin 40 | RB7/PGD — Digital I/O / ICSP data / Interrupt-on-change |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | EP — Exposed thermal pad (connect to VSS) |
Typical Applications
PIC18LF4420T-I/ML is suitable for 6 applications: Industrial Control Panels, Battery-Powered Sensor Nodes, HVAC Thermostats, Portable Instrumentation, Smart Energy Metering, Automotive Body Electronics (Non-Safety).
Industrial Control Panels
The PIC18LF4420T-I/ML is well-suited for industrial control panels requiring 36 I/O pins and a 10-bit ADC. Its 40 MHz CPU delivers 10 MIPS throughput, sufficient for real-time scanning of switch matrices, driving indicator LEDs, and managing relay-based actuator loads. The 2.0-5.5 V LF operating range simplifies integration with both legacy 5 V and modern 3.3 V logic, while the nanoWatt Technology sleep modes reduce quiescent current below 1 uA for standby efficiency. The 44-pin QFN package supports compact PCB layouts with sufficient copper area under the exposed thermal pad for thermal dissipation in enclosed industrial enclosures.
Recommended
Battery-Powered Sensor Nodes
Low-power sensor nodes benefit from the PIC18LF4420T-I/ML's nanoWatt Technology and 2.0 V minimum operating voltage, allowing operation directly from two AA cells across their discharge curve. The 10-bit ADC with 13 channels supports multi-sensor acquisition (temperature, humidity, light), while the MSSP and USART peripherals enable I2C sensor interfacing and UART communication with radio modules. Sleep current below 1 uA extends battery life to multiple years in duty-cycled wake-measure-transmit scenarios, and the 40 MHz performance burst handles protocol processing without requiring an external crystal in many designs.
Recommended
HVAC Thermostats
HVAC thermostat designs leverage the PIC18LF4420T-I/ML's combination of 10-bit ADC for temperature sensor reading (NTC thermistor or analog IC), PWM modules for controlling HVAC actuators and triac-fired loads, and Enhanced USART for communication with HVAC zoning systems. The 2.0-5.5 V supply range supports 24 VAC-derived rails after rectification, while the industrial -40C to +85C temperature range meets HVAC environmental specifications. The 16 KB Flash accommodates state-machine control logic, PID loop calculations, and user-interface handling for touchscreen or button-matrix interfaces without requiring an external memory expansion.
Recommended
Portable Instrumentation
Handheld test and measurement instruments benefit from the PIC18LF4420T-I/ML's 40 MHz CPU for fast ADC sampling, on-chip EEPROM for calibration constants and user preferences, and the 44-pin QFN package for compact PCB integration. The 10-bit ADC with 13 channels supports multi-range voltage measurement, while the MSSP peripheral drives SPI LCD displays or I2C-based digital potentiometers for autoranging. The low-voltage LF operation extends battery runtime in field-portable instruments, and the 256-byte EEPROM provides non-volatile storage for instrument configuration without external memory.
Recommended
Smart Energy Metering
Single-phase energy meter designs use the PIC18LF4420T-I/ML's 13-channel 10-bit ADC to sample voltage and current waveforms from current transformers and voltage dividers, while the 16-bit timer with CCP module captures zero-crossing events for power-factor calculation. The MSSP peripheral interfaces with EEPROM for accumulating energy totals, and the USART enables communication with concentrator modules via PLC or RF. The 2.0-5.5 V supply range accommodates direct operation from rectified mains-derived rails, and the industrial temperature range ensures metering accuracy in outdoor cabinet installations.
Recommended
Automotive Body Electronics (Non-Safety)
Non-safety automotive body modules (window lift controllers, mirror adjusters, interior lighting) use the PIC18LF4420T-I/ML where 36 I/O pins handle multiple motor and lighting loads, the PWM modules provide motor speed control, and the ADC monitors current feedback. The LF 2.0-5.5 V range supports direct connection to 12 V battery rails via 5 V regulators, while the -40C to +85C industrial temperature range covers cabin and engine-bay-adjacent installations. For safety-critical or AEC-Q100 applications, designers should select the PIC18F4xK20 family with automotive qualification instead.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4420T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4420-I/ML | PIC18LF4520T-I/ML | PIC18F4420T-I/ML | PIC18F46K20-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN (ML) | 44-pin QFN (ML) - same | 44-pin QFN (ML) - same | 44-pin QFN (ML) - same | 44-pin QFN (ML) - same |
| Program Memory (Flash) | 16 KB | 16 KB | 32 KB (+100%) | 16 KB | 64 KB (+300%) |
| Data SRAM | 768 bytes | 768 bytes | 1.5 KB (+100%) | 768 bytes | 3.9 KB (+420%) |
| Operating Voltage | 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 (narrower) | 1.8 V to 3.6 V (narrower) |
| Maximum CPU Speed | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 64 MHz (16 MIPS, +60%) |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 14 channels (+1) |
| Packaging Format | Tape & Reel (T suffix) | Tray (no T) | Tape & Reel | Tape & Reel | Tray (no T) |
Key Differentiators
- Drop-in upgrade with 2x memory available in same package (vs PIC18LF4520T-I/ML)
- Wider voltage range than F-series variant (vs PIC18F4420T-I/ML)
- Lower power consumption than F-series (vs PIC18F4420T-I/ML)
Design Notes
The QFN-44 package features an exposed thermal pad (pin 44) that MUST be soldered to a ground copper pour on the PCB to ensure mechanical reliability and thermal dissipation. Recommended minimum copper area is 1 square inch with at least 8 thermal vias (0.3 mm drill) connecting the top pad to internal ground planes. Inadequate soldering of the thermal pad is a common field failure mode for QFN packages.
Place 100 nF decoupling capacitors within 5 mm of each VDD pin (pins 11 and 32), with a single 10 uF bulk capacitor near the supply entry point. The PIC18LF4420's nanoWatt Technology allows deep sleep currents below 1 uA, but only if all unused I/O pins are configured as outputs (low) or inputs with the internal weak pull-up enabled to prevent floating-pin supply leakage. Avoid long PCB traces on VDD/VSS to prevent IR drops during ADC sampling.
When migrating code from PIC18F4420 to PIC18LF4420, ensure the BOR (Brown-Out Reset) voltage configuration bits match the supply range - the LF variant supports lower BOR thresholds (2.0 V vs 4.0 V on F-series). Configuration bits set for F-series will leave the LF device in an unstable state below 4 V. Additionally, the analog reference voltage pins (VREF+/VREF-) must be configured even when using internal references, or ADC readings will be incorrect.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Not AEC-Q100 qualified - choose PIC18F4xK20 automotive variants for AEC-Q100 applications. Halogen-free status not explicitly stated in datasheet.
