PIC18F4221-E/P - 8-bit 4KB Flash MCU, 40MHz, DIP-40 | Microchip
MPN: PIC18F4221-E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.95 | $7.95 |
| 10 | $7.15 | $71.50 |
| 100 | $6.32 | $632.00 |
| 500 | $5.65 | $2,825.00 |
| 1,000 | $5.05 | $5,050.00 |
PIC18F4221-E/P Overview
An 8-bit microcontroller is a single-chip computer built around an 8-bit data path, registers, and ALU. PIC18 microcontrollers use a RISC Harvard architecture with separate program and data buses, and the PIC18F family adds a 16-bit instruction word, hardware multiplier, and linear memory map optimized for C compilers. The PIC18F4221 sits in the '4x' family: 40-pin devices with nanoWatt power management, 10-bit ADC, and rich analog/peripheral integration for cost-sensitive embedded control.
Key features include 36 digital I/O pins, 13 channels of 10-bit ADC, two analog comparators, two CCP (Capture/Compare/PWM) modules, an MSSP configurable as SPI or I2C, an enhanced USART with LIN support, and self-programming flash with ICSP (In-Circuit Serial Programming). Four Timer modules (Timer0 through Timer3) handle timing, capture and PWM generation. nanoWatt technology provides idle, sleep and ultra-low-power wake-on-interrupt modes that reduce Iq to microampere levels for battery-backed designs.
Architecturally, the PIC18F4221 implements a 16-bit instruction set with an 8-bit data path, an 8x8 hardware multiplier, and a 31-level hardware stack. Internal RC oscillators plus PLL options free designs from external crystals; the ADC uses a successive-approximation core with acquisition timing controlled by the ADCON2 registers. Hardware peripherals are mapped to dedicated pins to keep firmware deterministic.
Typical applications include automotive body and climate controls, industrial sensor interfaces, appliance control boards, low-cost instrumentation, and embedded learning platforms. The PIC18F4221 is also widely used as a teaching MCU because the DIP-40 package is breadboard-friendly. Engineers designing with this part should budget I/O carefully: 36 I/O pins are ample for human-interface or sensor boards but tight for large parallel displays.
When designing with the PIC18F4221, place a 100 nF decoupling capacitor as close as possible to VDD/VSS pairs and consider a 10 uF bulk cap on the main rail. Unused I/O should be configured as outputs low to minimize SBDID current in sleep mode. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F4221-E/P — 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 PIC18F4221-E/P (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Program Memory (Flash), Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4221-I/P
✅ Drop-In✓ In Stock
$3.15 / Unit
View Datasheet →PIC18F4321-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4420-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4520-I/P
✅ Drop-In✓ In Stock
$5.35 / Unit
View Datasheet →PIC18F4221-E/P
✅ Drop-In✓ In Stock
$5.05 / Unit
View Datasheet →PIC18F2420-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4221-E/P Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC18 RISC |
| Instruction Set Width | 16-bit |
| Program Memory (Flash) | 4 KB (2K x 16) |
| RAM | 512 bytes |
| Data EEPROM | 256 bytes |
| Maximum Clock Frequency | 40 MHz |
| MIPS (Peak) | 10 MIPS |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, 13 channels |
| Comparators | 2 analog comparators |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | MSSP (SPI / I2C), EUSART with LIN |
| Timers | Timer0/1/2/3 (4 modules) |
| Package | PDIP-40 (DIP-40, 0.600 inch) |
| Mounting Type | Through-Hole |
| Operating Temperature | -40C to +125C (Automotive / -E grade) |
| Programming | ICSP (In-Circuit Serial Programming), Self-Programming |
| Power-Saving Modes | nanoWatt: Idle, Sleep, Low-Power modes |
PIC18F4221-E/P Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input or digital I/O RE3 |
| 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/T0CKI/C1OUT — PORTA bit 4 / Timer0 clock input / comparator 1 output |
| Pin 7 | RA5/AN4/SS/HLVDIN/C2OUT — PORTA bit 5 / analog input AN4 / SPI slave select / HLVD input / comparator 2 output |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / read control / analog input AN5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input AN6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input AN7 |
| Pin 11 | VDD — Positive power supply (4.2 V to 5.5 V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock input / PORTA bit 7 |
| Pin 14 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / PORTA bit 6 |
| Pin 15 | RC0/T1OSO/T13CKI — PORTC bit 0 / Timer1 oscillator output / Timer1/Timer3 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / MSSP SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / MSSP SPI data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / MSSP SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / EUSART TX / clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / EUSART RX / data |
| Pin 23 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 24 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 25 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 26 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 28 | RD5/PSP5/P1B — PORTD bit 5 / parallel slave port bit 5 / PWM1 complementary output |
| Pin 29 | RD6/PSP6/P1C — PORTD bit 6 / parallel slave port bit 6 / PWM1 output C |
| Pin 30 | RD7/PSP7/P1D — PORTD bit 7 / parallel slave port bit 7 / PWM1 output D |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive power supply (4.2 V to 5.5 V) |
| Pin 33 | RB0/INT0/FLT0 — PORTB bit 0 / external interrupt 0 / PWM fault input |
| Pin 34 | RB1/INT1 — PORTB bit 1 / external interrupt 1 |
| Pin 35 | RB2/INT2 — PORTB bit 2 / external interrupt 2 |
| Pin 36 | RB3/CCP2 — PORTB bit 3 / CCP2 I/O |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5/PGM — PORTB bit 5 / LVP programming input |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18F4221-E/P is suitable for 6 applications: Automotive Body and Climate Control Modules, Industrial Sensor Interface Boards, Embedded Learning and Prototyping Platforms, Appliance Control Boards (Washers, Ovens, Dishwashers), Low-Cost Instrumentation and Data Loggers, Hobby Robotics and Motor Control.
Automotive Body and Climate Control Modules
The PIC18F4221-E/P's -40C to +125C extended operating range and 36 I/O pins make it well suited for body control modules that read cabin temperature sensors, drive HVAC blower speeds, and multiplex indicator LEDs. Its 10-bit ADC with 13 channels handles mixed sensor inputs - thermistors, potentiometers, and current shunts - while the two CCP modules generate PWM outputs for blower and damper motors. The 4 KB flash comfortably fits typical HVAC control firmware including lookup tables for fan curves and PID loops.
Recommended
Industrial Sensor Interface Boards
In industrial instrumentation, the PIC18F4221-E/P aggregates analog signals from multiple sensors through its 13-channel 10-bit ADC and communicates results via EUSART (RS-232/RS-485) or MSSP (SPI/I2C) to a host controller. Its 40 MHz / 10 MIPS throughput supports real-time filter math and protocol framing, while nanoWatt sleep modes keep quiescent current low when the board is between measurement cycles. The extended temperature grade allows deployment near motors and process equipment without thermal derating.
Recommended
Embedded Learning and Prototyping Platforms
The DIP-40 through-hole package makes the PIC18F4221-E/P a popular MCU for breadboard-based learning kits and university courses. The PIC18's C-compiler-friendly 16-bit instruction set, hardware multiplier, and deep interrupt context lower the learning curve relative to PIC16 parts, while the 4 KB flash fits introductory projects like digital thermometers, line-following robots, and stepper-motor sequencers. Available MPLAB X IDE, XC8 compiler, and PICkit programmer support keep tooling costs low.
Recommended
Appliance Control Boards (Washers, Ovens, Dishwashers)
Home appliances need a low-cost MCU with ample I/O, robust ADC, and proven long-term reliability. The PIC18F4221-E/P drives relay boards, reads water-level and temperature sensors, multiplexes 7-segment or LED displays, and orchestrates washing cycles or cooking profiles. Its extended temperature rating handles the hot zones near ovens or dryer heaters, and the self-programmable flash enables field firmware updates via service-mode ICSP. The 40 MHz core runs state machines faster than 8 MHz PIC16 competitors.
Recommended
Low-Cost Instrumentation and Data Loggers
Portable data loggers for environmental monitoring, energy metering, and predictive maintenance use the PIC18F4221-E/P's 13-channel 10-bit ADC to sample multiple sensors sequentially, store buffered data in the 256-byte EEPROM, and transmit batches via EUSART. Sleep current below 1 uA in nanoWatt mode lets battery-powered loggers run for years between cell changes. The CCP modules time-stamp events and trigger wake-up from sleep, while the 36 I/O drive status LEDs, push-buttons, and a serial LCD.
Recommended
Hobby Robotics and Motor Control
Small hobby robots use the PIC18F4221-E/P to read IR/ultrasonic sensors through the ADC, drive DC and servo motors via the two CCP PWM channels, and coordinate navigation in a state machine. The 10 MIPS throughput is sufficient for sensor fusion at 100 Hz update rates, and the 36 I/O easily support a 2-wheel differential drive plus gripper or arm servos. The DIP-40 package and 5 V supply simplify breadboard prototyping and battery-pack power.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4221-E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4221-I/P | PIC18F4321-I/P | PIC18F4420-I/P | PIC18F4520-I/P | PIC18F2420-I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-40 (DIP-40) | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-28 (smaller) |
| Program Flash | 4 KB | 4 KB | 8 KB | 16 KB | 32 KB | 16 KB |
| RAM | 512 B | 512 B | 512 B | 768 B | 1536 B | 768 B |
| Data EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| 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) |
| I/O Pins | 36 | 36 | 36 | 36 | 36 | 23 |
| ADC Channels | 13 (10-bit) | 13 (10-bit) | 13 (10-bit) | 13 (10-bit) | 13 (10-bit) | 10 (10-bit) |
| Operating Temperature | -40C to +125C (E grade) | -40C to +85C (I grade) | -40C to +85C (I grade) | -40C to +85C (I grade) | -40C to +85C (I grade) | -40C to +85C (I grade) |
Key Differentiators
- Automotive -40C to +125C temperature grade (vs PIC18F4221-I/P)
- 4 KB flash - the lowest-cost DIP-40 PIC18 (vs PIC18F4520-I/P)
- Through-hole DIP-40 footprint for breadboard prototyping (vs PIC18F4221-I/ML (QFN-44))
Design Notes
Decouple the PIC18F4221-E/P VDD pins (11 and 32) with a 100 nF ceramic capacitor as close to each pin as practical, and add a bulk 10 uF electrolytic or tantalum on the main 5 V rail. If the analog VREF+ pin (RA3) is used, decouple it with 100 nF plus a small RC filter to reject digital switching noise from the digital VDD. Avoid powering the MCU through long inductive traces; place the bulk capacitor within 25 mm of the package.
Keep the 40 MHz crystal (or external clock) traces short and symmetric, with the load capacitors (typically 15-33 pF) placed within 5 mm of OSC1/OSC2. Route the ICSP signals (PGC/PGD on RB6/RB7) away from high-frequency switching nodes to prevent programming glitches. Leave a ground pour under the MCU and stitch the perimeter with via fences every 5-10 mm for EMI suppression on the DIP-40 footprint.
MCLR (pin 1) must be tied to VDD through a 10 kohm pull-up for normal operation; floating MCLR causes spurious resets. Do not leave any I/O pin unconfigured - configure unused pins as outputs driving low to minimize SBDID (~ 1 uA per pin) leakage in sleep mode. When using LVP (Low-Voltage Programming) via RB5/PGM, ensure RB5 is not pulled low at power-up or the MCU enters programming mode unintentionally.
The PDIP-40 package has a thermal resistance of approximately 50 C/W in still air and 35 C/W with moderate airflow. Estimated: at a 5 V supply drawing 50 mA typical load (250 mW dissipation), the junction rises only ~12 C above ambient in still air. For high-load applications near the extended +125 C ambient ceiling, derate to 80% of MIPS throughput or add a clip-on heatsink on the package top.
Compliance Information
RoHS/REACH/lead-free status not stated in verified web data; marked unknown pending confirmation from Microchip product page. AEC-Q100 explicitly not listed - the -E/ suffix denotes extended temperature grade but is not equivalent to AEC-Q100 automotive qualification. For AEC-Q100-qualified PIC18 alternatives, consult Microchip automotive-grade portfolio (e.g., PIC18F46K22-I/P with Q100).
