PIC18LF4220-I/ML - 8-bit PIC MCU, 4KB Flash, 44-QFN | Microchip
MPN: PIC18LF4220-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.48 | $64.80 |
| 100 | $5.76 | $576.00 |
| 500 | $5.18 | $2,590.00 |
| 1,000 | $4.61 | $4,610.00 |
PIC18LF4220-I/ML Overview
An 8-bit PIC microcontroller is a Harvard-architecture RISC device that fetches instructions and data through separate buses, allowing single-cycle instruction execution. The PIC18 family sits at the high-performance tier of Microchip's 8-bit MCU portfolio and is positioned hierarchically as: PIC18 -> PIC MCU -> 8-bit microcontroller -> microcontroller -> embedded processor. The 'LF' family designation specifically denotes the low-voltage, low-power variant optimized for applications where VDD is supplied directly from a battery or a low-headroom regulator.
Key features of the PIC18LF4220 include a 16-bit instruction word with an 8-bit data path, an internal 32 kHz to 8 MHz oscillator block, a 10-bit ADC with up to 13 input channels, and three timers plus a Capture/Compare/PWM (ECCP) module. The device supports ICSP (In-Circuit Serial Programming) for in-field firmware updates and self-programmability for bootloader-based upgrades. I/O count is 36, providing generous GPIO for keypad, display, and sensor interfacing without external expanders.
Architecturally, the PIC18LF4220 employs an enhanced RISC core capable of 10 MIPS at 40 MHz and integrates nanoWatt Technology power management with Idle and Sleep modes that drop quiescent current to microamp levels. The peripheral set is the same as the legacy PIC18F4220, providing a low-power migration path without firmware changes. The QFN-44 package with exposed pad improves thermal dissipation versus equivalent QFP packages, supporting sustained operation in enclosed industrial housings.
Typical applications include industrial control panels, sensor-conditioning front-ends, battery-powered metering, USB HID peripherals with PIC18-to-USB bridging, and appliance user-interface boards. The wide voltage range permits direct operation from 2xAA cells without an LDO, simplifying Bill-of-Materials in cost-sensitive designs.
Designers should confirm programmer/debugger compatibility (ICD 3, PICkit 4) before committing, and review the device errata sheet for any ADC or oscillator deviations on early silicon revisions.
This page synthesizes distributor pricing tiers, drop-in 8-bit MCU alternatives in the same QFN-44 footprint, and practical design notes not aggregated on individual distributor listings.
Drop-in alternatives for PIC18LF4220-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 PIC18LF4220-I/ML (same form factor and footprint) — differing in Package, Timers, ADC, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF4221-I/ML
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC18LF4320-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2320-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18LF4520-I/ML
✅ Drop-In✓ In Stock
$4.92 / Unit
View Datasheet →PIC18LF45K22-I/ML
✅ Drop-In✓ In Stock
$2.28 / Unit
View Datasheet →PIC18LF4220-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 RISC (Harvard) |
| Program Memory (Flash) | 4 KB |
| Data SRAM | 512 bytes |
| EEPROM | 256 bytes |
| Operating Voltage Range | 2.0 V to 5.5 V |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| I/O Pins | 36 |
| ADC | 10-bit, up to 13 channels |
| Timers | 3 (Timer0/1/2/3 depending on config) |
| PWM Modules | 1 ECCP + 2 CCP |
| Package | 44-pin QFN with exposed thermal pad |
| Operating Temperature (Industrial) | -40 C to +85 C |
| Mounting Type | Surface Mount |
| MSL Level | 3 |
| RoHS Status | Compliant |
| Programming Interface | ICSP (In-Circuit Serial Programming) |
PIC18LF4220-I/ML Pin Configuration
| Pin 1 | RA2/AN2 — PORTA I/O / Analog input |
| Pin 2 | RA3/AN3/VREF+ — PORTA I/O / Analog input / ADC VREF+ |
| Pin 3 | RA4/T0CKI — PORTA I/O / Timer0 clock |
| Pin 4 | RA5/AN4/SS/HLVDIN — PORTA I/O / Analog / SPI SS / High/Low-Voltage detect |
| Pin 5 | VDD — Positive supply voltage |
| Pin 6 | VSS — Ground reference |
| Pin 7 | OSC1/CLKI/RA7 — Crystal input / external clock in / PORTA I/O |
| Pin 8 | OSC2/CLKO/RA6 — Crystal output / clock out / PORTA I/O |
| Pin 9 | RC0/T1OSO/T1CKI — PORTC I/O / Timer1 oscillator |
| Pin 10 | RC1/T1OSI/CCP2 — PORTC I/O / Timer1 oscillator / CCP2 |
| Pin 11 | RC2/CCP1 — PORTC I/O / CCP1 PWM output |
| Pin 12 | RC3/SCK/SCL — PORTC I/O / SPI SCK / I2C SCL |
| Pin 13 | RC4/SDI/SDA — PORTC I/O / SPI SDI / I2C SDA |
| Pin 15 | RC5/SDO — PORTC I/O / SPI SDO |
| Pin 16 | RC6/TX/CK — PORTC I/O / USART TX / clock |
| Pin 17 | RC7/RX/DT — PORTC I/O / USART RX / data |
| Pin 18 | RB0/INT0/FLTA0 — PORTB I/O / External interrupt 0 |
| Pin 19 | RB1/INT1 — PORTB I/O / External interrupt 1 |
| Pin 20 | RB2/INT2 — PORTB I/O / External interrupt 2 |
| Pin 21 | RB3/CCP2 — PORTB I/O / CCP2 module |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | RB4 — PORTB I/O |
| Pin 24 | RB5 — PORTB I/O |
| Pin 25 | RB6/PGC — PORTB I/O / ICSP clock |
| Pin 26 | RB7/PGD — PORTB I/O / ICSP data |
| Pin 27 | RE0/RD/AN5 — PORTE I/O / Read control / analog |
| Pin 28 | RE1/WR/AN6 — PORTE I/O / Write control / analog |
| Pin 29 | RE2/CS/AN7 — PORTE I/O / Chip select / analog |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | VSS — Ground reference |
| Pin 32 | MCLR/VPP/RE3 — Master clear / Programming voltage / PORTE |
| Pin 33 | RA0/AN0 — PORTA I/O / Analog input 0 |
| Pin 34 | RA1/AN1 — PORTA I/O / Analog input 1 |
| Pin 35 | VDD — Positive supply voltage |
| Pin 36 | VSS — Ground reference |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | RD0/PSP0 — PORTD I/O / Parallel Slave Port |
| Pin 39 | RD1/PSP1 — PORTD I/O / Parallel Slave Port |
| Pin 40 | RD2/PSP2 — PORTD I/O / Parallel Slave Port |
| Pin 41 | RD3/PSP3 — PORTD I/O / Parallel Slave Port |
| Pin 42 | RD4/PSP4 — PORTD I/O / Parallel Slave Port |
| Pin 43 | RD5/PSP5 — PORTD I/O / Parallel Slave Port |
| Pin 44 | RD6/PSP6 — PORTD I/O / Parallel Slave Port |
| Pin EP | EP — Exposed thermal pad (solder to ground) |
Typical Applications
PIC18LF4220-I/ML is suitable for 6 applications: Industrial Sensor Conditioning, Battery-Powered Metering, Appliance User Interface Boards, USB HID Peripherals, Automotive Interior Modules, Educational and Hobby Development.
Industrial Sensor Conditioning
The PIC18LF4220-I/ML is well suited to industrial sensor-conditioning front-ends where 4KB Flash comfortably holds a state-machine scheduler and calibration table, while 2.0-5.5V VDD accepts a wide range of regulated rails. The 10-bit ADC with up to 13 input channels replaces an external ADC chip in compact designs, reducing BOM cost in PLC analog-input modules, process-transmitter heads, and field instrumentation. The QFN-44 footprint integrates cleanly onto mixed-signal sensor boards where the exposed pad is bonded to a ground pour for thermal stability. Use the ECCP module for PWM-driven excitation of resistive bridges, and capture mode for accurate pulse-width measurement of ultrasonic flow sensors.
Recommended
Battery-Powered Metering
The 'LF' 2.0-5.5V VDD range qualifies the PIC18LF4220-I/ML for direct battery operation from 2xAA cells, eliminating an LDO in cost-sensitive metering designs. The nanoWatt Sleep mode drops quiescent current below 1 microamp, extending shelf and operational life across decade-long deployments. Designers use this combination in water meters, gas meters, and simple electricity meters where the PIC18LF4220 wakes on a Hall-effect pulse, accumulates counts in EEPROM, and logs once per day. The 4KB Flash holds a metering state machine plus tamper-detection logic without requiring external memory.
Recommended
Appliance User Interface Boards
The PIC18LF4220-I/ML drives appliance HMI boards with 36 GPIO pins sufficient for keypad scanning, LED matrix control, and segment LCD multiplexing. The 3 CCP/ECCP channels deliver PWM for backlight dimming, buzzer tones, and triac-fired motor control in white-goods designs. Industrial (-40C to +85C) temperature rating supports under-hood appliance environments. Use the USART for service-port communication via opto-isolated UART, and the I2C/SPI for digital temperature sensor and EEPROM expansion.
Recommended
USB HID Peripherals
Although the PIC18LF4220 itself lacks an integrated USB peripheral, Microchip's design ecosystem pairs it with the PIC18F2550 family for cost-optimized USB HID bridges. Designers use the PIC18LF4220 as a sub-MCU communicating with a USB-capable PIC via UART or SPI in compact peripherals. The 4KB Flash handles enumeration glue and HID report formatting, leaving the upstream USB PIC for protocol handling. This partitioned approach trades a few cents of BoM cost for proven USB stack stability.
Recommended
Automotive Interior Modules
Although the standard PIC18LF4220-I/ML is industrial-grade (-40C to +85C), Microchip offers automotive-qualified variants of the PIC18 family for interior lighting, HVAC controls, and accessory switch modules. The QFN-44 footprint is automotive-vendor-accepted for behind-dash modules where vibration requires the exposed-pad mechanical robustness of QFN over QFP. Designers pair the MCU with CAN transceivers such as the MCP2515 for body-controller communication in non-safety-critical interior applications.
Recommended
Educational and Hobby Development
The PIC18LF4220-I/ML is featured in Microchip's developer kits and university curricula, paired with PICkit 4 and MPLAB X IDE. The 4KB Flash and 36 GPIO provide sufficient complexity to teach interrupts, ADC pipelines, and PWM while remaining debuggable on a single weekend project. Hobbyists use it for retro gaming displays, robotic controllers, and homebrew synthesisers where the LF low-voltage compatibility simplifies portable, battery-driven constructions.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF4220-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF4221-I/ML | PIC18LF4320-I/ML | PIC18LF4520-I/ML | PIC18LF45K22-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFN with EP (ML) | 44-pin QFN with EP (ML) - same | 44-pin QFN with EP (ML) - same | 44-pin QFN with EP (ML) - same | 44-pin QFN with EP (ML) - same |
| Flash Memory | 4 KB | 64 KB | 8 KB | 32 KB | 32 KB |
| SRAM | 512 bytes | 4 KB | 768 bytes | 1.5 KB | 1.5 KB |
| 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 (NOT drop-in for battery) | 2.0 V to 5.5 V |
| Maximum CPU Speed | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 64 MHz (16 MIPS) |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| Architecture Series | PIC18F legacy | PIC18F legacy | PIC18F legacy | PIC18F legacy | PIC18 K-series (enhanced) |
Key Differentiators
- Wide 2.0V-5.5V VDD eliminates external LDO on battery designs (vs PIC18F4220 (standard-voltage legacy))
- 16x memory upgrade path in same QFN-44 footprint (vs PIC18LF4221-I/ML)
- Enhanced K-series core option with 60% more MIPS (vs PIC18LF45K22-I/ML)
Design Notes
The PIC18LF4220-I/ML accepts a wide 2.0V-5.5V VDD range, but bulk decoupling still requires a 100nF ceramic cap within 5mm of each VDD pin and a 10uF tantalum or ceramic bulk cap near the regulator output. Place the bulk cap first in the power-trace path to minimize voltage droop during CCP PWM transitions where peak currents spike 50-100mA above baseline. Avoid using VDD pin pairs (5/30/35 in this package) as power-ground returns for analog signals to prevent digital switching noise coupling.
A common engineering pitfall: do not enter ICSP programming mode with a fully discharged decoupling network. Always ensure VDD rises within the tVTP time window per datasheet, otherwise the MCLR/VPP pin may latch and the ICSP handshake will fail intermittently. Additionally, the exposed thermal pad (EP) must be soldered to a ground pour for package mechanical reliability - omitting the EP solder connection risks reflow-induced package cracking on thermal cycling.
Estimated: At 40 MHz CPU clock with 36 GPIO toggling at 25% duty, peak ground-bounce noise on a 4-layer PCB with a 5mm x 5mm ground pour is roughly 150-250 mV; a 6-layer stackup reduces this by 30-50%. Place the crystal oscillator traces (OSC1/OSC2) within 5mm of the package, keep them matched-length within 1mm, and guard them with a ground trace on each side. The ICSP PGC/PGD lines should be routed with a 4.7k pull-up on MCLR and a 100-ohm series terminator near the connector.
Compliance Information
RoHS compliant per Microchip product declaration; lead-free NiPdAu plating. Industrial -40C to +85C temperature range. Not AEC-Q100 qualified - choose automotive-grade PIC18F variants for AEC-Q100 compliance.
