PIC18F4420-E/PT - 8-Bit 40MHz 16KB Flash MCU 44-TQFP | Microchip
MPN: PIC18F4420-E/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.05 | $80.50 |
| 100 | $7.16 | $716.00 |
| 500 | $6.27 | $3,135.00 |
| 1,000 | $5.38 | $5,380.00 |
PIC18F4420-E/PT Overview
What is a PIC18F microcontroller? PIC18F is Microchip's high-performance 8-bit PIC microcontroller family that bridges legacy 8-bit designs to modern connectivity. It sits within the PICmicro -> 8-bit MCU -> microcontroller -> embedded controller hierarchy. The PIC18F architecture features a 16-bit instruction word, hardware multiply, and a 31-level stack with 77 instructions - balancing code density, deterministic interrupt latency, and ease of programming via MPLAB X IDE.
Key features include 36 digital I/O pins arranged across 5 ports (PORTA-PORTE), a 10-bit ADC with up to 13 input channels, two capture/compare/PWM (CCP) modules, an Enhanced CCP (ECCP) module, two USART modules, one MSSP (SPI/I2C), and a 10-bit DAC-style PWM output. The nanoWatt technology provides multiple power-managed modes (Run, Idle, Sleep) and a low-power Timer1 oscillator, enabling standby currents below 1 uA typical.
Technically, the PIC18F4420 implements a Harvard architecture with separate program and data buses, hardware Multiply, and 32 KB addressable program space. The integrated ICSP (In-Circuit Serial Programming) and ICD (In-Circuit Debug) interfaces allow flash programming and real-time debugging directly on the production PCB using MPLAB ICD 3/4 or PICkit 5 programmers, eliminating the need for socketed parts.
Typical applications include industrial sensor signal conditioning with the on-chip ADC, motor control with the ECCP module driving half-bridges, automotive body controllers operating in extended temperature, consumer appliance control panels, and USB-to-UART bridges using the dual USART. The wide supply range (4.2 V to 5.5 V) accommodates regulated 5 V rails.
When designing with this MCU, reserve pin 1 (MCLR/VPP) for a proper reset network with a 10 kohm pull-up and a 100 nF cap to ground, and ensure the internal PLL settings match the oscillator configuration bits to avoid clock-failure lockups.
This page consolidates distributor pricing, AEC-Q100 cross-reference, drop-in alternatives, and practical MPLAB-based design notes not present in the bare datasheet - offering engineers a faster procurement and design-verification path.
Drop-in alternatives for PIC18F4420-E/PT — 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 PIC18F4420-E/PT (same form factor and footprint) — differing in Operating Temperature, Package, Timers, Program Memory (Flash), ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4420-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4420-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4525-I/PT
✅ Drop-In✓ In Stock
$4.18 / Unit
View Datasheet →PIC18F4550-I/PT
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC18F4620-I/PT
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC18F46K20-I/PT
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F4420-E/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 Harvard RISC |
| Instruction Set Width | 16-bit |
| Maximum Clock Speed | 40 MHz |
| Program Flash Memory | 16 KB (8K x 16 words) |
| SRAM | 768 bytes |
| EEPROM | 256 bytes |
| Supply Voltage | 4.2 V to 5.5 V |
| Digital I/O Pins | 36 |
| ADC | 10-bit, up to 13 channels |
| Timers | 4 (Timer0-Timer3) |
| CCP Modules | 2 CCP + 1 ECCP |
| Communication | 2x USART, 1x MSSP (SPI/I2C) |
| Package | 44-pin TQFP (10x10 mm) |
| Operating Temperature | -40C to +125C (Extended, "E") |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| MSL Level | 3 (168 hours) |
| Debug Interface | ICSP / ICD via MPLAB |
PIC18F4420-E/PT Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI Slave Select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel port / AN5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Write control / AN6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Chip Select / AN7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI — Oscillator crystal input / external clock in |
| Pin 14 | OSC2/CLKO/RA6 — Oscillator crystal output / PORTA bit 6 |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / clock in |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6/TX2 — PORTD bit 6 / Parallel Slave Port / USART2 TX |
| Pin 30 | RD7/PSP7/RX2 — PORTD bit 7 / Parallel Slave Port / USART2 RX |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 34 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 35 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 36 | RB3/CCP2A — PORTB bit 3 / CCP2 alt output |
| Pin 37 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 38 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | VSS — Ground reference (bottom paddle isolated or pin) |
| Pin 42 | NC — Not connected |
| Pin 43 | NC — Not connected |
| Pin 44 | NC — Not connected |
Typical Applications
PIC18F4420-E/PT is suitable for 6 applications: Industrial Sensor Signal Conditioning, Automotive Body Control Module, Consumer Appliance Control Panel, Brushless DC Motor Control, USB-to-UART Bridge Adapter, Educational Microcontroller Trainer.
Industrial Sensor Signal Conditioning
The PIC18F4420-E/PT is well-suited for industrial sensor signal conditioning because its 10-bit ADC with up to 13 input channels can directly digitize analog signals from thermocouples, RTDs, pressure transducers, and 4-20 mA current-loop sensors. With 16 KB of flash and 768 bytes SRAM, the MCU runs typical sensor linearization, moving-average filtering, and HART protocol parsing in MPLAB XC8 C without external memory. The -40C to +125C extended temperature grade (E suffix) lets the same part operate in unheated factory cabinets and outdoor installations. The 36 digital I/O pins drive status LEDs, relay coils, and opto-isolated inputs simultaneously. Compared to a discrete op-amp + ADC + uC design, the PIC18F4420 consolidates signal chain and logic on a single chip.
Recommended
Automotive Body Control Module
The PIC18F4420-E/PT's extended -40C to +125C temperature grade makes it a direct fit for automotive body control modules managing lighting, wipers, door locks, and seat controllers. The 2 CCP and 1 ECCP modules drive MOSFET half-bridges for window lifters and headlamp ballasts with hardware PWM resolution independent of CPU load. Dual USART interfaces connect to LIN bus masters and K-line diagnostic interfaces concurrently, while the MSSP runs SPI for dashboard LCD displays. AEC-Q100 screening is not performed on the PIC18F4420 itself, but the E temperature grade plus automotive design practice (load-dump TVS, watchdog) supports under-hood and cabin ECUs. The 44-TQFP footprint tolerates conformal coating for humidity resistance.
Recommended
Consumer Appliance Control Panel
In consumer appliances like washing machines, microwaves, and dishwashers, the PIC18F4420-E/PT serves as the main user-interface controller driving 7-segment displays, button matrices, and buzzer feedback. The 36 I/O pins are sufficient for the keypad scan, LED driving, and triac-fired heater/load control without external I/O expanders. nanoWatt power-managed modes (Sleep draws under 1 uA typical) let the appliance meet standby power regulations such as Energy Star and EU Lot 6. The integrated EEPROM stores user presets (wash cycle, temperature) without external NVM. Programming via ICSP over a 2-pin header on the production board eliminates socketed parts in manufacturing.
Recommended
Brushless DC Motor Control
The PIC18F4420-E/PT controls small brushless DC (BLDC) motors in fans, pumps, and power tools through its Enhanced CCP (ECCP) module, which generates complementary PWM outputs with programmable dead-time insertion - critical for safely driving half-bridges without shoot-through. Hall-sensor or back-EMF commutation logic fits within 16 KB flash. The 10-bit ADC samples motor current via shunt resistors for current-mode control and stall detection. With 40 MHz operation, the control loop runs at 10 MIPS, supporting up to 20 kHz PWM with comfortable overhead for sensor processing and user interface code. Step-up/down companion ICs handle higher-voltage battery rails.
Recommended
USB-to-UART Bridge Adapter
While the PIC18F4420-E/PT lacks an integrated USB peripheral, its dual USARTs plus MSSP (configurable as SPI or I2C) make it a flexible serial-bridge or protocol-converter MCU. A typical application pairs the PIC18F4420 with an external USB-serial converter IC (e.g., MCP2200 or FT232) to provide UART-to-UART bridging, RS-232/RS-485 level translation, or industrial Modbus RTU slave endpoints. The 16 KB flash accommodates Modbus, DLMS, or custom protocol stacks with library functions, while 768 bytes SRAM buffers incoming frames. MPLAB XC8 PRO mode generates compact code suitable for the 16 KB flash budget.
Recommended
Educational Microcontroller Trainer
The PIC18F4420-E/PT is commonly used in university embedded systems courses and hobbyist projects because it is supported by free MPLAB X IDE and free MPLAB XC8 C compiler with no code-size restrictions at optimization level 1. The 44-TQFP version simplifies breadboard-friendly breakout boards, and the ICSP header allows students to flash and debug code without removing the chip. Its 16 KB flash, 36 I/O, and rich peripherals (ADC, USART, MSSP) teach concepts spanning GPIO, timers, PWM, and serial communication within a single semester project - driving servos, reading sensors, and displaying on LCDs simultaneously.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4420-E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4420-I/PT | PIC18F4525-I/PT | PIC18F4550-I/PT | PIC18F4620-I/PT | PIC18F46K20-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Program Flash | 16 KB | 16 KB | 48 KB | 32 KB | 64 KB | 64 KB |
| SRAM | 768 bytes | 768 bytes | 3,981 bytes | 2,048 bytes | 3,968 bytes | 3,898 bytes |
| Max Clock Speed | 40 MHz | 40 MHz | 40 MHz | 48 MHz | 40 MHz | 64 MHz |
| Supply 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 | 1.8 V to 3.6 V |
| Operating Temperature | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| USB Interface | No | No | No | Yes (USB 2.0 FS) | No | No |
Key Differentiators
- Extended temperature grade (-40C to +125C) standard (vs PIC18F4420-I/PT)
- TQFP-44 surface-mount package (vs PIC18F4420-I/P (DIP-40))
- Free MPLAB XC8 compiler support with no code-size cap at -O1 (vs PIC18F4550 (requires paid PRO license for >16KB))
Design Notes
Place two 100 nF decoupling capacitors as close as possible to pins 11 (VDD) and 32 (VDD) to the ground plane, plus a bulk 10 uF tantalum or ceramic on each VDD rail. Add a 100 nF cap on pin 1 (MCLR/VPP) for noise filtering. Avoid long power traces that share switching currents with the MCU core - star-ground the digital and analog grounds at a single point near pin 12/31 (VSS) to minimize ADC reference noise.
Route the 40 MHz crystal (pins 13/14) traces as short, symmetric loops with guard ground, keeping them away from digital switching lines. Place the ICSP header (RB6/PGC, RB7/PGD, MCLR) on the board edge for production programming access - Microchip's PICkit 5 and ICD 4 use a 6-pin RJ-style connector. Reserve at least 1 mm clearance between TQFP-44 leads and adjacent signal traces for rework hand-soldering, and add a thermal relief spoke pattern on the four corner pads if hand-rework is anticipated.
Do not leave the MCLR pin floating - it requires a 10 kohm pull-up to VDD for normal operation and a 100 nF cap for noise immunity, or the MCU will intermittently reset or fail to start. Always configure the oscillator configuration bits (CONFIG1H) in the C source code with #pragma config directives - a missing or incorrect FOSC setting can cause clock-failure lockup that requires a high-voltage programmer to recover. When migrating from PIC18F4420 to PIC18F4525, verify ADC channel count and CCP module mapping - the pin assignments differ on PORTB.
Compliance Information
RoHS compliant per Microchip product page. The PIC18F4420-E/PT is NOT AEC-Q100 qualified; for AEC-Q100 automotive requirements use PIC18F46K80-I/PT or PIC18F47K40-I/PT (explicitly Q100 screened). E temperature grade (-40C to +125C) supports industrial but does not replace automotive Q100 screening.