PIC18F2420T-I/SO - 8-Bit 40MHz 16KB Flash MCU 28-SOIC | Microchip
MPN: PIC18F2420T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.5 | $5.50 |
| 10 | $4.95 | $49.50 |
| 100 | $4.4 | $440.00 |
| 500 | $3.95 | $1,975.00 |
| 1,000 | $3.5 | $3,500.00 |
PIC18F2420T-I/SO Overview
A PIC18 microcontroller is an 8-bit Harvard-architecture RISC microcontroller from Microchip's PIC18 family, part of the broader category of microcontrollers -> embedded MCUs -> integrated circuits. The PIC18 family introduced design enhancements over earlier PIC16 devices such as a 16-bit instruction word, hardware multiply, linear memory map and C-friendly architecture, while retaining the classic PIC peripheral set. PIC18 devices are widely used where deterministic low-power control is needed alongside moderate on-chip resources.
Key features of this part include a 10-bit ADC with up to 10 channels, one 8-bit and three 16-bit timers, two capture/compare/PWM modules, an enhanced USART (EUSART), an MSSP port supporting SPI and I2C (master/slave), two analog comparators, nanoWatt power-management modes, and a 25 I/O count with 5.5 V tolerant digital ports. The integrated nanoWatt technology allows dynamic switching of idle, sleep and run modes, reducing quiescent current in battery-powered designs.
The PIC18F2420 architecture is built around a 16-bit instruction path fed by a Flash program memory and an 8-bit data path, with separate program and data buses (Harvard). The 40 MHz maximum clock delivers up to 10 MIPS throughput - typical of the high-performance tier of the PIC18 family - while nanoWatt mode allows the CPU and peripherals to be selectively clock-gated to extend battery life in sleep states.
Typical applications for the PIC18F2420T-I/SO include industrial sensor conditioning and motor control loops, low-cost 5 V logic-replacement controllers, USB-to-UART bridges (when paired with external PHYs), home appliance control boards, general-purpose sensor hubs, and educational/development platforms. Designers leverage the PIC18 toolchain (MPLAB X IDE, XC8 compiler, MPLAB PICkit programmers) for code development and in-circuit debug.
When designing with this part, ensure the 4.2 V to 5.5 V supply rail is decoupled with at least a 100 nF ceramic close to VDD plus a bulk 10 uF capacitor, and add a 100 nF on AVCC for ADC accuracy. The MCLR pin must be pulled high through a 10 kohm resistor for normal operation, and analog/digital supplies must be tied together if the ADC is unused. This page synthesizes distributor pricing, same-package drop-in alternatives, and practical design notes beyond the manufacturer datasheet.
Drop-in alternatives for PIC18F2420T-I/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 PIC18F2420T-I/SO (same form factor and footprint) — differing in Package, Timers, Core Architecture, Internal Oscillator, Watchdog Timer.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2420-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-E/SO
✅ Drop-In✓ In Stock
$3.93 / Unit
View Datasheet →PIC18F2420T-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2320T-I/SO
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F23K20T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2520T-I/SO
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC18F2420T-I/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Maximum CPU Frequency | 40 MHz (10 MIPS) |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data RAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 10 channels |
| Timers | 1 x 8-bit, 3 x 16-bit |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | EUSART, MSSP (SPI / I2C) |
| Comparators | 2 analog comparators |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 28-pin SOIC (Wide, 300 mil) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Power-Saving Modes | nanoWatt Technology |
PIC18F2420T-I/SO 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 negative reference |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / ADC positive reference |
| 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 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — Oscillator input / external clock / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — Oscillator output / clock output / PORTA bit 6 |
| Pin 11 | RC0/T1OSO/T13CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / EUSART TX / synchronous clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / EUSART RX / synchronous data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 21 | RB0/INT0/AN10 — PORTB bit 0 / external interrupt 0 / analog input 10 |
| Pin 22 | RB1/INT1/AN8 — PORTB bit 1 / external interrupt 1 / analog input 8 |
| Pin 23 | RB2/INT2/AN9 — PORTB bit 2 / external interrupt 2 / analog input 9 |
| Pin 24 | RB3/AN9 — PORTB bit 3 / analog input 9 |
| Pin 25 | RB4/AN11 — PORTB bit 4 / analog input 11 |
| Pin 26 | RB5/PGM — PORTB bit 5 / LVP programming |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18F2420T-I/SO is suitable for 6 applications: Industrial Sensor Hub & Data Acquisition, Home Appliance Control Boards, USB-to-UART Bridge / Protocol Translator, Hobbyist & Educational Development Platform, Automotive Body & Comfort Electronics (Non-Safety), Low-Cost Logic Replacement & Glue Controller.
Industrial Sensor Hub & Data Acquisition
The PIC18F2420T-I/SO is well suited to industrial 5 V sensor-hub and data-acquisition nodes where its 10-bit ADC with up to 10 channels digitizes analog transducer signals (temperature, pressure, 4-20 mA loop interfaces) while the 40 MHz core executes filtering and protocol framing. The MSSP runs I2C/SPI to local sensors and the EUSART bridges to RS-485 backbones, and the 25 I/O drive LEDs and digital isolators. With nanoWatt modes, the device idles below 1 uA typical between scans, extending battery life in remote nodes. Industrial temperature rating (-40 C to +85 C) and 4.2 V to 5.5 V supply tolerance match 24 V industrial bus systems with on-board regulation. Designers typically pair it with the MCP2551 CAN transceiver or MAX485 RS-485 transceiver for fieldbus connectivity.
Recommended
Home Appliance Control Boards
The PIC18F2420T-I/SO is widely used in white-goods control boards (washing machines, dishwashers, microwave ovens, induction cooktops) where its 16 KB Flash holds motor-control state machines, the 2 CCP modules generate PWM for triac-driven AC loads and DC motor H-bridges, and the 10-bit ADC reads NTC thermistors for closed-loop temperature control. The 5 V tolerant I/O ports drive LED indicators and triac optocouplers directly through current-limiting resistors. nanoWatt power-saving modes keep standby power below EU eco-design limits (typically <0.5 W). Industrial temperature rating handles under-cabinet thermal stress and the SOIC-28 footprint simplifies single-sided PCB layouts. Pair with the MOC3041 zero-cross optotriac and ULN2003 driver for AC load switching.
Recommended
USB-to-UART Bridge / Protocol Translator
The PIC18F2420T-I/SO serves as the controller in low-cost USB-to-UART and UART-to-SPI/I2C bridge dongles where its EUSART handles serial framing and the MSSP drives I2C/SPI peripherals on the downstream side. At 40 MHz the core bit-bangs USB Low-Speed via the internal comparator and interrupt-on-change (or interfaces to an external USB transceiver such as the MCP2200). 16 KB Flash accommodates CDC class drivers or vendor-specific protocols, and 768 B RAM is enough for small FIFOs. The 5 V supply simplifies bus-powered dongles. Common pairs include the MCP2200 USB-UART bridge companion IC, but the PIC18F2420 can implement the entire bridge in firmware for higher-margin designs.
Recommended
Hobbyist & Educational Development Platform
The PIC18F2420T-I/SO is a canonical microcontroller for hobbyist and university curricula where the 28-pin SOIC drop-in footprint mates with breadboard-friendly breakout boards, the 16 KB Flash fits introductory C and assembly projects, and the MPLAB X IDE + XC8 compiler + PICkit 5 programmer provide a free end-to-end toolchain. The industrial temperature tolerance forgives student lab mishandling, and the rich peripheral set (ADC, PWM, I2C, SPI, UART) supports full-semester lab sequences from GPIO to motor control. Tutorials, application notes and example firmware are abundant in Microchip's documentation library. The 28-SOIC package is also well-suited to reflow-solder training kits and Maker PCB projects.
Recommended
Automotive Body & Comfort Electronics (Non-Safety)
The PIC18F2420T-I/SO targets non-safety automotive body and comfort subsystems (interior lighting, seat controllers, mirror adjusters, accessory multiplexers) where the 25 I/O drive LED drivers and H-bridge motor pre-drivers, the 10-bit ADC reads potentiometers and current shunts, and the MSSP links to LIN slaves via external transceivers. For under-hood or harsh-environment modules, designers migrate to the -E (extended -40 C to +125 C) variant of the PIC18F2420 family, which remains AEC-Q100 capable and pin-compatible. nanoWatt modes support key-off quiescent budgets below 100 uA. The 28-SOIC footprint eases ECU miniaturization and single-sided PCB assembly.
Recommended
Low-Cost Logic Replacement & Glue Controller
The PIC18F2420T-I/SO is often deployed as a pin-configurable logic replacement that consolidates discrete 74HC logic gates, latches and timers into a single programmable device, reducing PCB area and BOM cost. With 25 I/O and 40 MHz performance, it can implement PWM generators, watchdog supervisors, button debouncers, and protocol converters that would otherwise require 4-6 separate logic ICs. Industrial temperature rating and 5 V tolerance make it tolerant of legacy industrial rails, and the 16 KB Flash stores configuration parameters in EEPROM. The SOIC-28 package is hand-solderable for prototypes and small production runs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2420T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2420-I/SO | PIC18F2420-E/SO | PIC18F2420T-E/SO | PIC18F2320T-I/SO | PIC18F23K20T-I/SO | PIC18F2520T-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-pin SOIC (Wide, 300 mil) | 28-pin SOIC (Wide, 300 mil) - same | 28-pin SOIC (Wide, 300 mil) - same | 28-pin SOIC (Wide, 300 mil) - same | 28-pin SOIC (Wide, 300 mil) - same | 28-pin SOIC (Wide, 300 mil) - same | 28-pin SOIC (Wide, 300 mil) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory (Flash) | 16 KB | 16 KB | 16 KB | 16 KB | 8 KB | 8 KB | 32 KB |
| Maximum CPU Frequency | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 64 MHz (16 MIPS) | 40 MHz |
| Data RAM | 768 bytes | 768 bytes | 768 bytes | 768 bytes | 512 bytes | 512 bytes | 1536 bytes |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Packaging | Tape & Reel | Tube | Tube | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel |
| 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 5.5 V | 4.2 V to 5.5 V |
Key Differentiators
- Tape & Reel packaging suited for high-volume SMT assembly (vs PIC18F2420-I/SO (Tube))
- Industrial -40 C to +85 C temperature range (vs PIC18F2420-E/SO (Extended -40 C to +125 C))
- Higher 16 KB Flash vs PIC18F2320 family (vs PIC18F2320T-I/SO)
Design Notes
Decouple VDD with at least a 100 nF ceramic capacitor placed within 5 mm of the pin, plus a bulk 10 uF tantalum or aluminum electrolytic on the same rail. AVCC must track VDD within +/-0.3 V; tie AVCC to VDD through a ferrite bead or direct short when the ADC is unused, and add a separate 100 nF on AVCC. The MCLR pin must be pulled high through a 10 kohm resistor; do not leave it floating. Brown-out reset is enabled by default at 4.0 V (BOREN0=1) and should remain enabled for 5 V industrial supplies to avoid code corruption during dips.
Place the 28-SOIC on a 300-mil SOIC land pattern with continuous ground pour under the chip body. Route the crystal traces (OSC1/OSC2, pin 9/10) short and symmetric, surrounded by a grounded guard trace to reduce EMI coupling into the analog inputs. Keep ADC traces away from PWM outputs and switching nodes. The analog input traces (AN0-AN4) should be guarded and decoupled at the connector with 100 nF. For 40 MHz operation, total MCU trace lengths should stay under 25 mm on oscillator pins to preserve clock integrity.
Do not exceed 5.5 V on any pin including MCLR - transients above this rating latch up the device. Verify the CONFIG bits for the oscillator mode (HS for >4 MHz crystal, XT for 1-4 MHz, RC for cost-sensitive designs) before programming; incorrect configuration is the most common bring-up failure. When migrating from PIC18F2420 to PIC18F2520, double-check the analog pin assignments because PIC18F2520 has 13 ADC channels versus 10 on PIC18F2420. Do not connect VUSB or D+/D- directly to PORT pins without series resistors and ESD protection - the PIC18F2420 is not USB-native.
Compliance Information
RoHS and lead-free confirmed by Microchip product page; not AEC-Q100 qualified for automotive - migrate to PIC18F2420-E/SO or PIC18F2520-E/SO for harsh-environment automotive designs.
