PIC18F2221-E/SO - 8-bit 25MHz 4KB Flash MCU 28-SOIC | Microchip
MPN: PIC18F2221-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.82 | $4.82 |
| 10 | $4.4 | $44.00 |
| 100 | $3.78 | $378.00 |
| 500 | $3.32 | $1,660.00 |
| 1,000 | $2.95 | $2,950.00 |
| 3,000 | $2.55 | $7,650.00 |
PIC18F2221-E/SO Overview
A microcontroller (MCU) is a single-chip computer that combines a CPU, program and data memory, peripherals, and I/O on one IC. The PIC18F family sits between the 8-bit PIC16 line and the 16-bit dsPIC33/PIC24 families, offering higher performance (10 MIPS vs 5 MIPS), enhanced peripherals, and wider Flash density while retaining the easy-to-learn PIC instruction set. The PIC18F2221 belongs to the smaller pin-count (28/40/44-pin) Enhanced Flash MCU family, optimized for cost-sensitive general-purpose embedded designs.
Key features of the PIC18F2221-E/SO include nanoWatt power management for low-power sleep and idle modes, a wide operating temperature range (the “E” suffix denotes -40C to +125C extended grade), 512 bytes of SRAM, and 256 bytes of EEPROM for non-volatile data. The 25 MHz oscillator produces 100 ns instruction cycles, with a 4x PLL option available. The internal architecture is a Harvard design with separate program and data buses, allowing simultaneous instruction fetch and data access.
Typical applications include consumer white goods, home appliance controls, low-end sensor hubs, automotive body electronics (with extended temperature grade), industrial control panels, and low-bandwidth motor control. The 13-channel 10-bit ADC suits temperature, voltage, and current sensing; the CCP modules drive simple PWM actuators. Per Microchip documentation, the part is upward code-compatible with PIC16C5X, PIC12CXXX, PIC16CXX, and PIC17CXX devices, easing legacy code migration.
When designing with this MCU, ensure decoupling capacitors (typically 0.1 uF ceramic) are placed within 5 mm of VDD/VSS pins. The 28-SOIC package exposes 25 I/O; reserve pins for MCLR (reset), OSC1/OSC2 (crystal) or INTOSC for new designs. Program the device via ICSP using the PGD/PGC pair.
This page synthesizes distributor pricing, drop-in alternatives, and design guidance beyond what the manufacturer datasheet alone provides, sourced from DigiKey, Mouser, and Microchip product pages.
Drop-in alternatives for PIC18F2221-E/SO — 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 PIC18F2221-E/SO (same form factor and footprint) — differing in ADC, Operating Temperature, Package, Core Architecture, Communication.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2221-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2321-E/SO
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC18F4321-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4520-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2221-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2221-E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18F 8-bit RISC |
| Program Memory | 4 KB Flash |
| RAM | 512 bytes |
| EEPROM | 256 bytes |
| Instruction Set | 77 single-word instructions |
| Maximum Clock Speed | 40 MHz (10 MIPS) |
| Operating Frequency | 25 MHz typical (10 MIPS) |
| Supply Voltage | 4.2 V to 5.5 V |
| I/O Pins | 25 |
| ADC | 10-bit, 13 channels |
| Comparators | 2 |
| CCP/ECCP Modules | 2 |
| Serial Communication | SSP (SPI / I2C), USART |
| Package | 28-SOIC (0.295", 7.50 mm) |
| Operating Temperature | -40C to +125C (E = extended) |
| Power-Saving Mode | nanoWatt technology |
| In-Circuit Debug | ICD via ICSP (PGD/PGC) |
PIC18F2221-E/SO Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input or ICSP programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input AN0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input AN1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / analog input AN2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input AN3 / ADC VREF+ |
| Pin 6 | RA4/AN4 — PORTA bit 4 / analog input AN4 |
| Pin 7 | RA5/AN5 — PORTA bit 5 / analog input AN5 |
| Pin 8 | VDD — Positive supply voltage |
| Pin 9 | OSC1/CLKI/RA7 — Crystal oscillator input or external clock |
| Pin 10 | OSC2/CLKO/RA6 — Crystal oscillator output or clock output |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator |
| Pin 12 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM/capture/compare |
| Pin 14 | RC3/SCL/SCK — PORTC bit 3 / I2C SCL or SPI SCK |
| Pin 15 | RC4/SDA/SDI — PORTC bit 4 / I2C SDA or SPI SDI |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI SDO |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX or clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX or data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (second VDD pin) |
| Pin 21 | RB0/AN12/INT0 — PORTB bit 0 / analog input AN12 / external interrupt 0 |
| Pin 22 | RB1/AN10/INT1 — PORTB bit 1 / analog input AN10 / external interrupt 1 |
| Pin 23 | RB2/AN8/INT2 — PORTB bit 2 / analog input AN8 / external interrupt 2 |
| Pin 24 | RB3/AN9/CCP2 — PORTB bit 3 / analog input AN9 / CCP2 |
| Pin 25 | RB4/AN11 — PORTB bit 4 / analog input AN11 |
| Pin 26 | RB5/AN13 — PORTB bit 5 / analog input AN13 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18F2221-E/SO is suitable for 6 applications: Consumer White Goods Control, Automotive Body Electronics, Industrial Sensor Hubs, Home Appliance UI / Display, Low-End Motor / Fan Control, Educational & Development Boards.
Consumer White Goods Control
The PIC18F2221-E/SO suits front-panel and motor-control boards in washing machines, dryers, and dishwashers where 4 KB of Flash holds state-machine plus UI code, and the 13-channel 10-bit ADC reads thermistor, water-level, and motor-current sensors. The -40C to +125C extended grade tolerates under-cabinet and motor-housing temperatures, while nanoWatt sleep modes cut standby power below 1 uA between user events. Two CCP modules generate PWM for motor and buzzer drivers directly, avoiding an external PWM controller. The 28-SOIC footprint drops onto legacy PIC18F2220 boards with no PCB rework.
Recommended
Automotive Body Electronics
Body controllers for window lifts, mirror adjusters, seat heaters, and ambient lighting use the PIC18F2221-E/SO at 25 MHz to drive MOSFET half-bridges via the two CCP/PWM channels, multiplex switch matrices on the 25 GPIO, and wake from CAN or LIN activity via the EUSART interrupt. The -40C to +125C extended grade is AEC-Q100 qualified by Microchip for under-dash modules. The 4 KB Flash holds a small RTOS-style scheduler and LIN slave stack; the 256-byte EEPROM stores trim and learned positions across battery disconnects. The 28-SOIC footprint is footprint-compatible with the automotive PIC18F4321 upgrade path.
Recommended
Industrial Sensor Hubs
Distributed sensor nodes in factory automation fit the PIC18F2221-E/SO because the 13-channel 10-bit ADC scans multiple analog inputs (temperature, pressure, humidity transducers) in sequence while the SSP port reads SPI or I2C digital sensors. The 10 MIPS core runs a 1 kHz control loop and an averaged ADC filter without CPU loading. The -40C to +125C grade supports control-panel interiors and unconditioned outdoor enclosures. nanoWatt idle draws 100 nA typical, allowing battery or harvested-energy operation. The 28-SOIC package and ICSP pins support field firmware updates via handheld programmers.
Recommended
Home Appliance UI / Display
Front-panel boards for microwaves, coffee machines, and induction cookers run user-interface code on the PIC18F2221-E/SO: scan key matrices on 25 GPIO, drive LED-segment or character LCDs, and read rotary encoders via the CCP input-capture mode. The 4 KB Flash accommodates state machines plus small UI string tables; the 512-byte SRAM holds the display buffer and a debounce queue. The extended temperature grade tolerates the inside of a closed-door oven cavity or an induction-coil under-cabinet where ambient can reach 105C. The PIC18F2221-E/SO 28-SOIC footprint matches Microchip reference layouts for production.
Recommended
Low-End Motor / Fan Control
BLDC and brushed-DC motor control for fans, pumps, and small appliances fits the PIC18F2221-E/SO at 25 MHz when using the 2 CCP/PWM channels for FET gate drive and the 13-channel ADC for back-EMF and current sensing. Software-only PID with 1 ms loop time runs at ~5% CPU load, leaving headroom for UART diagnostics. The extended -40C to +125C grade covers motor-housing locations. The 256-byte EEPROM stores tuned PID gains per production batch. Same 28-SOIC footprint as PIC18F4321-E/SO allows Flash upgrade for firmware A/B testing.
Recommended
Educational & Development Boards
University microcontroller courses and hobbyist development boards standardize on the PIC18F2221-E/SO because the 28-SOIC footprint is breadboard-friendly via breakout adapters and the ICSP pins allow direct PICkit connection. The 4 KB Flash is large enough for capstone projects covering ADC, PWM, I2C, and SPI while small enough to teach linker mapping. The -40C to +125C grade means a single part covers every lab environment. Microchip's MPLAB Xpress cloud IDE plus XC8 free tier supports the device out of the box, making it a teaching-friendly drop-in choice.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2221-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2221-I/SO | PIC18F2321-E/SO | PIC18F4321-E/SO | PIC18F4520-E/SO | PIC18LF2221-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) |
| Flash Memory | 4 KB | 4 KB | 8 KB | 8 KB | 32 KB | 4 KB |
| RAM | 512 B | 512 B | 512 B | 768 B | 1536 B | 512 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| Operating Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V |
| ADC Channels | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit | 13 x 10-bit |
| Operating Temperature | -40C to +125C (E grade) | -40C to +85C (I grade) | -40C to +125C (E grade) | -40C to +125C (E grade) | -40C to +125C (E grade) | -40C to +85C (I grade) |
| Maximum Clock | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) |
Key Differentiators
- Extended temperature grade (-40C to +125C) for under-hood and outdoor enclosures (vs PIC18F2221-I/SO)
- On-chip 13-channel 10-bit ADC with internal bandgap reference (vs PIC18F2220-I/SO)
- Industry-standard 28-SOIC footprint with PICkit-compatibility and code migration path (vs PIC18F2321-E/SO)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of each VDD pin (8 and 20) and a single 10 uF bulk capacitor on the supply rail. The PIC18F2221-E/SO draws up to 50 mA active at 40 MHz and 1 uA typical in sleep; the bulk capacitor prevents VDD droop during ADC burst sampling. For noise-sensitive analog reads, gate ADC sampling with a 50 us software delay after waking from sleep to allow the internal bandgap reference to settle.
Route the ICSP signals PGD (pin 28) and PGC (pin 27) as short 50 ohm traces directly to a 6-pin header, with no nearby switching signals crossing the traces at right angles. Place the MCLR pull-up (typically 10 kohm to VDD) close to pin 1. The 28-SOIC has a 7.50 mm body width; allow 0.1" minimum clearance around the part for hand-solder rework. Keep analog inputs AN0-AN13 away from digital switching traces and clocks by at least 2 mm or shield with a ground pour.
Do not leave the MCLR pin floating — always tie it to VDD through a 10 kohm resistor (or to a reset supervisor). Unused I/O pins should be configured as outputs driving low or inputs with the internal weak pull-up enabled, never left as high-impedance floating. When using the ADC, do not exceed VDD + 0.3 V on any analog input; the datasheet (document 39609F) requires input current limiting to 20 mA if a voltage excursion is possible. Finally, do not operate the part outside the 4.2 V to 5.5 V range — for lower voltages, switch to the PIC18LF2221 variant.
Compliance Information
RoHS compliant per Microchip product page. The “E” grade is qualified to AEC-Q100 for automotive body and chassis electronics. Halogen-free status not explicitly listed in the verified data and is recorded as unknown. Lead-free (Pb-free) finish per Microchip package marking guide.
