PIC18F4420T-I/PT - 40MHz 8-bit MCU, 16KB Flash | Microchip
MPN: PIC18F4420T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.24 | $6.24 |
| 10 | $5.62 | $56.20 |
| 100 | $4.95 | $495.00 |
| 500 | $4.42 | $2,210.00 |
| 1,000 | $3.99 | $3,990.00 |
| 3,000 | $2.8098 | $8,429.40 |
PIC18F4420T-I/PT Overview
An 8-bit microcontroller is a single-chip computer built around an 8-bit data path and Harvard architecture, integrating CPU, RAM, non-volatile program memory, peripherals, and I/O on one die. Within the broader taxonomy, the PIC18F4420 belongs to the PIC18F enhanced-flash family -> PIC18 family -> PIC microcontrollers (MCU) -> microcontrollers -> microprocessors and microcontrollers -> semiconductors. The 'T' suffix in the MPN denotes Tape-and-Reel packaging and the 'I' indicates the Industrial temperature grade (-40C to +85C), while 'PT' designates the TQFP-44 package.
Key features include 36 digital I/O pins, a 10-bit Analog-to-Digital Converter (ADC) with up to 13 input channels, two USART modules, one MSSP (Master Synchronous Serial Port) supporting both SPI and I2C, two Capture/Compare/PWM (CCP) modules, one Enhanced CCP (ECCP), four 8-bit timers and three 16-bit timers, nanoWatt Technology for power management, and an 8x8 hardware multiplier. The 16 KB Flash supports self-programming and ICSP (In-Circuit Serial Programming).
Architecturally, the PIC18F4420 uses an enhanced RISC Harvard architecture with 16-bit instructions and 8-bit data, achieving up to 10 MIPS (Million Instructions Per Second) at 40 MHz. It features separate instruction and data buses, a 32-level hardware stack, 31 interrupt sources with priority levels, and a software-controlled low-power Sleep mode for battery-friendly designs.
Typical applications include industrial sensor interfaces, consumer appliance control, building automation, HVAC controls, motor control (low-power brushed DC), and battery-powered instruments where the 16 KB Flash and 768-byte SRAM are sufficient for control logic, protocol handling, and ADC sampling.
When designing with the PIC18F4420, allocate proper decoupling (100 nF ceramic per VDD/VSS pair), keep traces to the 20 MHz crystal short, and consult Microchip MPLAB XC8 compiler and PICkit 5 programmer documentation for the development environment. Verify that total I/O sink current does not exceed the 200 mA absolute maximum across all ports.
This page synthesizes distributor pricing, drop-in same-package alternatives from Microchip, and design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for PIC18F4420T-I/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 PIC18F4420T-I/PT (same form factor and footprint) — differing in Package, Operating Temperature, Timers, ADC, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4420-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4520-I/PT
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F4410-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4480-I/PT
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC18F4523-I/PT
✅ Drop-In✓ In Stock
$3.25 / Unit
View Datasheet →PIC18F4420-E/PT
✅ Drop-In✓ In Stock
$5.38 / Unit
View Datasheet →PIC18F4420T-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Instruction Set Architecture | Enhanced Harvard, 16-bit instructions / 8-bit data |
| Program Memory (Flash) | 16 KB (8K x 16) |
| SRAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Frequency | 40 MHz (10 MIPS) |
| Operating Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 36 |
| ADC | 10-bit, up to 13 channels |
| Communication Interfaces | 2x USART, 1x MSSP (SPI / I2C) |
| Timers | 4x 8-bit, 3x 16-bit |
| Capture/Compare/PWM | 2x CCP + 1x ECCP |
| Operating Temperature | -40C to +85C (Industrial grade, 'I') |
| Package | 44-pin TQFP (10x10 mm), 'PT' suffix, Tape & Reel 'T' |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Lead-free per Microchip product page |
| In-Circuit Programming | ICSP (In-Circuit Serial Programming) |
| Hardware Multiplier | 8x8 hardware multiplier |
PIC18F4420T-I/PT Pin Configuration
| Pin 1 | MCLR/RE3 — Master Clear (reset) input / digital I/O pin RE3 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / analog channel 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / parallel port read / analog channel 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / parallel port write / analog channel 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / parallel port chip select / analog channel 7 |
| Pin 11 | VDD — Positive power supply (4.2V to 5.5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 14 | OSC2/CLKO — Crystal oscillator output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 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 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / parallel slave port data 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / parallel slave port data 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / parallel slave port data 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / parallel slave port data 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 / USART clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / parallel slave port data 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / parallel slave port data 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / parallel slave port data 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / parallel slave port data 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive power supply (4.2V to 5.5V) |
| 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 alternate 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 input |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data I/O |
| Pin 41 | RA6/OSC2/CLKO — Alternate oscillator output (per datasheet, secondary OSC2 option) |
| Pin 42 | RA7/OSC1/CLKI — Alternate oscillator input (per datasheet, secondary OSC1 option) |
| Pin 43 | AVSS — Analog ground reference |
| Pin 44 | AVDD — Analog positive power supply (4.2V to 5.5V) |
Typical Applications
PIC18F4420T-I/PT is suitable for 7 applications: Industrial Sensor Interface, Consumer Appliance Control, Building Automation / HVAC, Motor Control (Brushed DC / Small BLDC), Battery-Powered Instrumentation, Smart Sensor / IoT Edge Node, Automotive Aftermarket (Non-AEC) Clusters.
Industrial Sensor Interface
The PIC18F4420T-I/PT fits industrial sensor interfaces because its 36 I/O pins and 10-bit ADC (up to 13 channels) handle multiple analog and digital sensors on a single chip. With 16 KB Flash and 768 B SRAM it runs averaging, calibration, and MODBUS RTU protocol stacks for 4-20 mA or 0-10V transducer conditioning. The 40 MHz core and ECCP module support PWM-driven excitation for load-cell and bridge sensors. Per the datasheet, the 4.2-5.5V supply and industrial temperature grade (-40C to +85C) match factory-floor environments without extra regulation.
Recommended
Consumer Appliance Control
The PIC18F4420T-I/PT powers washing machines, microwave ovens, and dishwasher controllers where 16 KB Flash holds the state-machine firmware and the 768 B SRAM buffers keypad/display traffic. The 2x USARTs connect to inverters and motor drivers while the MSSP (SPI/I2C) drives OLED or segment displays and capacitive touch keypads. nanoWatt Technology enables <1 uA Sleep current between user interactions, extending battery life in portable appliances. Industrial temperature grade and 4.2-5.5V operation tolerate the noisy switched-mode supplies typical in white goods.
Recommended
Building Automation / HVAC
The PIC18F4420T-I/PT runs HVAC thermostat and damper-controller firmware thanks to its 13 ADC channels (for NTC10K temperature, humidity, and pressure sensors), 2x CCP/ECCP for TRIAC phase-angle control, and USART for BACnet/Modbus uplinks. The 256-byte EEPROM stores user schedules and calibration constants through power cycles. Per the Microchip datasheet, the 40 MHz instruction rate is more than enough for PID loops on thermal control valves at 100 ms loop times. The industrial -40C to +85C range suits rooftop and basement HVAC cabinets.
Recommended
Motor Control (Brushed DC / Small BLDC)
The PIC18F4420T-I/PT drives low-power brushed DC motors and small sensorless BLDC pumps because its Enhanced CCP (ECCP) module generates complementary PWM with programmable dead-time up to 40 MHz / 8 = 5 MHz resolution. The 10-bit ADC samples back-EMF or current shunt at 100 kS/s for closed-loop speed control. With 16 KB Flash, you can fit sensorless BLDC start-up routines, commutation tables, and overcurrent protection firmware. The TQFP-44 footprint provides enough I/O for three-phase gate-driver enable signals, Hall inputs, and fault feedback.
Recommended
Battery-Powered Instrumentation
The PIC18F4420T-I/PT supports portable data loggers, hand-held multimeters, and field-test instruments thanks to its nanoWatt Technology - Sleep current as low as 100 nA with RTC running, and IDD < 2.5 mA at 5V/4 MHz per the datasheet. The 16 KB Flash stores configuration and calibration, while 256-byte EEPROM retains user data for 40 years. The PIC's built-in ADC samples sensor inputs and the USART streams data over RS-232/RS-485. Industrial temperature range tolerates outdoor and lab environments.
Recommended
Smart Sensor / IoT Edge Node
The PIC18F4420T-I/PT acts as a sensor-hub MCU for IoT edge nodes where it aggregates analog/digital sensors and relays data via UART to an ESP32 or RN2483 LoRa modem. The 36 I/O and 13 ADC channels accommodate multi-sensor PCBs (gas, temperature, light, accelerometer), while the MSSP drives I2C sensors and SPI flash. Per the datasheet, ICSP and self-programmable Flash enable over-the-air firmware updates from the modem. The 40 MHz core computes local thresholding and FFT-lite preprocessing, offloading the wireless SoC.
Recommended
Automotive Aftermarket (Non-AEC) Clusters
The PIC18F4420T-I/PT drives aftermarket motorcycle/scooter dashboards and gauge clusters thanks to its 36 I/O pins handling 7-segment displays, status LEDs, and switch inputs. The ECCP module generates backlight PWM, while the ADC reads fuel-level and temperature sensors. Note: the standard PIC18F4420T-I/PT is industrial-grade (-40C to +85C), NOT AEC-Q100 qualified - select PIC18F4580-I/PT or PIC18F4680-I/PT for OEM automotive. The 16 KB Flash fits gauge graphics, unit conversion, and CAN-bus optional add-on.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4420T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4420-I/PT | PIC18F4520-I/PT | PIC18F4410-I/PT | PIC18F4480-I/PT | PIC18F4523-I/PT | PIC18F4420-E/PT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (PT) 10x10 mm | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same |
| Program Flash | 16 KB | 16 KB (identical) | 32 KB (+100%) | 16 KB (same) | 16 KB (same) | 32 KB (+100%) | 16 KB (same die) |
| SRAM | 768 bytes | 768 B (identical) | 1.5 KB (+100%) | 768 B (same) | 768 B (same) | 1.5 KB (+100%) | 768 B (same) |
| EEPROM | 256 bytes | 256 B (identical) | 256 B (same) | 256 B (same) | 256 B (same) | 256 B (same) | 256 B (same) |
| Maximum CPU Frequency | 40 MHz (10 MIPS) | 40 MHz (identical) | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) | 40 MHz (same die) |
| ADC Resolution | 10-bit | 10-bit (identical) | 10-bit (same) | 10-bit (same) | 10-bit (same) | 12-bit (upgrade) | 10-bit (same die) |
| CAN Controller | No | No (identical) | No | No | Yes (CAN 2.0B, feature add) | No | No (same die) |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (identical) | -40C to +85C (same) | -40C to +85C (same) | -40C to +85C (same) | -40C to +85C (same) | -40C to +125C (Extended, upgrade) |
Key Differentiators
- Best-in-class 16 KB Flash with 768-byte SRAM in 44-pin TQFP at sub-$4 pricing (vs PIC18F4520-I/PT)
- Backward-compatible drop-in upgrade to PIC18F4480 for adding CAN 2.0B (vs PIC18F4480-I/PT)
- Standard-package TQFP-44 with all 44 pins usable vs 40-pin DIP variants (vs PIC18F4520-I/P (DIP-40))
Design Notes
The PIC18F4420T-I/PT operates from a single 4.2-5.5V supply; place one 100 nF ceramic decoupling capacitor within 5 mm of every VDD/AVDD pin pair and a shared 10 uF tantalum or ceramic bulk capacitor near the IC. Brown-out reset is configurable to 4.0/4.2/4.5V via configuration bits - select 4.2V for 5V rails with 5% tolerance, or 4.5V for systems with extended transients.
Keep traces from the 20 MHz crystal or resonator (pins 13/14) shorter than 10 mm and surround them with a ground guard ring to avoid coupling noise into the ADC reference. Route AVSS/AVDD separately from digital VSS/VDD and join them only at the PCB star-ground point. The 10-bit ADC can achieve 8 ENOB if analog traces are length-matched and the ADC acquisition time is set to >= 1.4 us per the datasheet AC characteristics.
Estimated: at full 40 MHz operation, IDD is approximately 16 mA typical / 25 mA maximum at 5V per the Microchip PIC18F4420 datasheet, dissipating 80-125 mW in the TQFP-44 package (theta_JA approximately 45 C/W on a 4-layer JEDEC test board). No heatsink is required for industrial-temperature operation; a 4-layer PCB with at least 1 cm^2 of copper-pour VSS ground plane is sufficient. Estimated junction temperature rise is approximately 6 C above ambient under maximum load.
Do not exceed 200 mA total I/O sink current across all ports (per datasheet absolute maximum). When driving inductive loads (relays, solenoids, motors), add snubbing diodes and ensure ECCP dead-time is programmed >500 ns to prevent cross-conduction. Always configure the unused I/O pins as outputs driving low, or as inputs with internal pull-ups enabled - never leave them floating - to minimize Sleep current. The MSSP module supports both SPI and I2C; the I2C pins (RC3/RC4) are open-drain and require external pull-ups 1-10 kOhm to VDD.
For long-distance RS-485 / RS-232 communication, place a 100 Ohm series termination at the USART TX/RX pins (RC6/RC7) and use a TVS diode (e.g., PESD5V0L1BA) at the connector to suppress ESD strikes. The 13 ADC channels share a single sample-and-hold capacitor; if you switch channels rapidly, allow at least 1.4 us acquisition time and add a small RC filter (1 kOhm + 100 pF) on each analog input to limit source impedance and prevent cross-channel contamination.
Compliance Information
RoHS and REACH compliant per Microchip product page. Lead-free / halogen-free per Microchip PIC18F4420 product family documentation. NOT AEC-Q100 qualified - use PIC18F4580/PIC18F4680 for automotive. Conflict-minerals declaration available on Microchip.com.
