PIC18F4220T-I/ML - 4KB Flash 8-bit MCU, 44-pin QFN | Microchip
MPN: PIC18F4220T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.45 | $5.45 |
| 10 | $4.96 | $49.60 |
| 100 | $4.46 | $446.00 |
| 500 | $4.05 | $2,025.00 |
| 1,000 | $3.64 | $3,640.00 |
PIC18F4220T-I/ML Overview
What is a PIC18F microcontroller? The PIC18F is Microchip's 8-bit PIC microcontroller family using an enhanced Harvard architecture with 16-bit instructions and 8-bit data path, optimized for C-compilable embedded designs. PIC18F sits in the hierarchy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC. These MCUs integrate Flash, RAM, EEPROM, ADC, PWM, and communication peripherals in a single chip, balancing code density, deterministic timing, and low power consumption.
Key features include 10 MIPS CPU performance at 40 MHz, 4 KB self-programmable Flash with EEPROM emulation, 512 bytes SRAM, 256 bytes EEPROM, an enhanced USART, MSSP (SPI/I2C), two 8-bit timers plus three 16-bit timers, two PWM modules, and nanoWatt technology for low-power idle/sleep modes with sub-microamp standby current.
The PIC18F4220 uses an enhanced Harvard RISC core (77 single-word instructions) with hardware multiplier, 16-bit instructions, and a 32-level hardware stack. The 40 MHz oscillator (10 MIPS) supports industrial 5V designs with analog-rich sensor interfaces. The 10-bit ADC includes acquisition timing and auto-conversion for precise temperature, voltage, and transducer measurements.
Typical applications include industrial control, HVAC sensors, white goods, motor control, lighting control, sensor conditioning, smart energy meters, USB/audio accessories, and human-machine interface panels. The wide I/O count and ADC channels fit multi-signal acquisition boards.
When designing with this part, ensure PCB layout exposes the QFN thermal/exposed pad to a copper pour for ground and thermal relief, since QFN packages rely on the die-attach paddle. Verify VIH/VIL thresholds match 5V logic and add 0.1 uF + 10 uF decoupling near the VDD pins.
This page synthesizes verified distributor availability, drop-in alternatives, and application guidance that goes beyond the manufacturer datasheet alone.
Drop-in alternatives for PIC18F4220T-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 PIC18F4220T-I/ML (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, Timers, Program Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4420T-I/ML
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F4520T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F46K20T-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4220-I/ML
✅ Drop-In✓ In Stock
$3.97 / Unit
View Datasheet →PIC18F4320T-I/ML
✅ Drop-In✓ In Stock
$3.15 / Unit
View Datasheet →PIC18F4220T-I/ML Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Family | PIC18F |
| Core Architecture | Enhanced Harvard RISC, 77 instructions |
| Program Memory (Flash) | 4 KB |
| Data SRAM | 512 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, 13 channels |
| PWM Modules | 2 (10-bit) |
| Timers | 2 x 8-bit + 3 x 16-bit |
| Communication | EUSART, MSSP (SPI / I2C) |
| Package | 44-pin QFN (ML) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| RoHS Status | Compliant |
PIC18F4220T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 2 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 3 | RA2/AN2/VREF- — Digital I/O / Analog input channel 2 / ADC Vref- |
| Pin 4 | RA3/AN3/VREF+ — Digital I/O / Analog input channel 3 / ADC Vref+ |
| Pin 5 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 6 | RA5/AN4/SS — Digital I/O / Analog input 4 / SPI slave select |
| Pin 7 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock / digital I/O |
| Pin 8 | OSC2/CLKO/RA6 — Crystal oscillator output / clock out / digital I/O |
| Pin 9 | RC0/T1OSO/T13CKI — Digital I/O / Timer1 oscillator output / Timer1/3 clock |
| Pin 10 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 output |
| Pin 11 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 12 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 13 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 14 | RC5/SDO — Digital I/O / SPI data out |
| Pin 15 | RC6/TX/CK — Digital I/O / EUSART TX / clock |
| Pin 16 | RC7/RX/DT — Digital I/O / EUSART RX / data |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply (4.2 V to 5.5 V) |
| Pin 19 | RB0/INT0/FLT0 — Digital I/O / external interrupt 0 / PWM fault input |
| Pin 20 | RB1/INT1 — Digital I/O / external interrupt 1 |
| Pin 21 | RB2/INT2 — Digital I/O / external interrupt 2 |
| Pin 22 | RB3/CCP2 — Digital I/O / CCP2 output |
| Pin 23 | RB4 — Digital I/O / interrupt-on-change |
| Pin 24 | RB5 — Digital I/O / interrupt-on-change |
| Pin 25 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 26 | RB7/PGD — Digital I/O / ICSP data |
| Pin 27 | MCLR/VPP/RE3 — Master clear reset / programming voltage / digital I/O |
| Pin 28 | RD0 — Digital I/O |
| Pin 29 | RD1 — Digital I/O |
| Pin 30 | RD2 — Digital I/O |
| Pin 31 | RD3 — Digital I/O |
| Pin 32 | RD4 — Digital I/O |
| Pin 33 | RD5 — Digital I/O |
| Pin 34 | RD6 — Digital I/O |
| Pin 35 | RD7 — Digital I/O |
| Pin 36 | VSS — Ground reference |
| Pin 37 | VDD — Positive supply (4.2 V to 5.5 V) |
| Pin 38 | RE0/RD — Digital I/O / parallel slave port read |
| Pin 39 | RE1/WR — Digital I/O / parallel slave port write |
| Pin 40 | RE2/CS — Digital I/O / parallel slave port chip select |
| Pin 41 | AVSS — Analog ground reference |
| Pin 42 | AVDD — Analog positive supply |
| Pin 43 | RC0/T1OSO/T13CKI — Digital I/O (alternate pin remap) |
| Pin 44 | EP — Exposed thermal pad - tie to ground |
Typical Applications
PIC18F4220T-I/ML is suitable for 6 applications: Industrial Sensor Node, HVAC Control Board, White Goods User Interface, Lighting Control Module, Smart Energy Meter, Human-Machine Interface Panel.
Industrial Sensor Node
The PIC18F4220T-I/ML fits industrial sensor nodes because of its 4.2V-5.5V VDD, 36 I/O, and thirteen 10-bit ADC channels with built-in acquisition timing. With 4 KB Flash and 512 bytes RAM, it runs C-compiled firmware for temperature, pressure, flow, and switch sensors. The nanoWatt technology supports idle modes under 1 uA for line-powered industrial installations. Place decoupling capacitors (0.1 uF + 10 uF) near VDD, and use the QFN exposed pad as a thermal/ground anchor on a 1-oz copper pour.
Recommended
HVAC Control Board
HVAC control boards need a 5V-tolerant MCU with rich ADC and PWM channels for fan speed, damper, and thermistor interfaces. The PIC18F4220T-I/ML provides 13 10-bit ADC inputs (multi-zone temperature and pressure), 2 PWM modules (fan and valve control), and EUSART (modbus or BACnet link). 4 KB Flash fits typical HVAC firmware with state-machine control loops, while the -40 C to +85 C industrial grade handles unconditioned plant rooms. Tie MCLR through 10 kohm pullup and add watchdog timer config bits for unattended operation.
Recommended
White Goods User Interface
The PIC18F4220T-I/ML is well suited for white goods user interface boards (washing machines, dishwashers, ovens) because of its 36 I/O pins for keypad, LED, and 7-segment display, plus EUSART for control-board link. Its 5V VDD matches legacy appliance power rails and industrial-grade temperature range handles under-cabinet heat. 4 KB Flash runs menu logic, key debounce, and fault routines; 512 bytes RAM handles display buffers. Use hardware PWM for buzzer tones and CCP for triac-zero-cross timing.
Recommended
Lighting Control Module
Lighting control modules benefit from the PIC18F4220T-I/ML's 2 PWM modules for dimming, 13 ADC channels for ambient-light and occupancy sensing, and EUSART for DMX-512 or DALI bridges. Its 4 KB Flash stores dim curves and scene presets; the nanoWatt idle modes drop standby power for always-on wall switches. Use optoisolators on TRIAC outputs for mains isolation and a 5V regulator fed from the line side. The 44-pin QFN provides a low-profile package suitable for slim wall-plate designs.
Recommended
Smart Energy Meter
Smart energy meters leverage the PIC18F4220T-I/ML's 10-bit ADC (13 channels) to sample current transformers and voltage dividers for kWh computation. Its 5V operation matches analog front-end op-amps and the EUSART/MSSP peripherals link to PLC or wireless modules for AMR. With 4 KB Flash, the meter can store tariffs and logging; 256 bytes EEPROM stores non-volatile configuration. Use the QFN's exposed pad for ground return on the analog section, and keep ADC traces away from TRIAC switching nodes.
Recommended
Human-Machine Interface Panel
The PIC18F4220T-I/ML drives small HMI panels with its 36 I/O to scan keypads, drive character LCDs, and serialize data to a master controller via EUSART. The 4 KB Flash fits menu logic, RTC emulation via Timer1, and fault diagnostics; 512 bytes RAM handles LCD buffers. Its -40 C to +85 C industrial range suits factory-floor panels. Use the MSSP (SPI) to drive graphical LCDs and the CCP module for backlight PWM dimming; add ESD protection on all user-facing pins.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4220T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4420T-I/ML | PIC18F4520T-I/ML | PIC18F46K20T-I/ML | PIC18F4320T-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) | 4 KB | 16 KB | 32 KB | 64 KB | 8 KB |
| Data SRAM | 512 bytes | 768 bytes | 1.5 KB | 3.6 KB | 512 bytes |
| Data EEPROM | 256 bytes | 256 bytes | 256 bytes | 1 KB | 256 bytes |
| Maximum CPU Speed | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 64 MHz (16 MIPS) | 40 MHz (10 MIPS) |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 1.8 V to 5.5 V | 4.2 V to 5.5 V |
| I/O Pins | 36 | 36 | 36 | 36 | 36 |
| ADC | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 13 channels | 10-bit, 14 channels | 10-bit, 13 channels |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) |
Key Differentiators
- Legacy PIC18 baseline with broad code base and tool support (vs PIC18F46K20T-I/ML)
- Lower cost entry point with adequate Flash for small firmware (vs PIC18F4320T-I/ML)
- True 5V VDD tolerance without voltage translation (vs PIC18F46K20T-I/ML)
Design Notes
The PIC18F4220T-I/ML's 44-pin QFN package dissipates heat through the exposed thermal pad (EP) on pin 44. Solder the EP to a PCB copper pour of at least 0.5 square inches connected to ground. For industrial sensor designs at 40 MHz and 5 V, the device draws approximately 10-15 mA active, giving sub-100 mW dissipation that the QFN handles without active cooling. Always verify EP-to-ground continuity with a 4-wire milliohm measurement during PCB QA.
Place 0.1 uF ceramic decoupling capacitors as close as possible (within 3 mm) to each VDD pin (pins 18 and 37), plus a bulk 10 uF tantalum or aluminum polymer capacitor near the IC. AVdd (pin 42) and AVss (pin 41) require an RC low-pass filter (10 ohm + 0.1 uF) to keep ADC reference noise below 1 LSB. The nanoWatt technology enables idle currents under 1 uA when peripherals are gated off - refer to datasheet section on Sleep modes for proper peripheral disable sequencing.
Route the ICSP pins RB6/PGC (pin 25) and RB7/PGD (pin 26) directly to a 6-pin header (0.1 inch pitch) for in-circuit programming and debug. Keep the trace length under 50 mm and add 4.7 kohm pullups to VDD on PGC/PGD to prevent programming glitches. The MCLR/VPP pin (pin 27) requires a 10 kohm pullup to VDD and a 100 nF capacitor to ground for in-circuit programming. Avoid running high-current traces under the QFN's exposed pad to maintain ground integrity.
Common pitfalls with the PIC18F4220T-I/ML include: (1) forgetting to configure the oscillator mode bits in CONFIG1H for the correct clock source, (2) leaving the WDT enabled in production firmware without periodic clear, causing unintended resets, (3) using ADC without adequate acquisition time leading to inaccurate conversions, and (4) failing to set the BOR (brown-out reset) voltage threshold to match 5V operation. Always set CONFIG2L with the proper BOR level and CONFIG1H with HS or XT oscillator mode for 40 MHz crystals.
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade (-40 C to +85 C). Not AEC-Q100 qualified - choose PIC18F46K20 automotive variants for automotive applications.
