PIC18F2420-I/SP - 8-Bit 40MHz MCU 16KB Flash 28-SPDIP | Microchip
MPN: PIC18F2420-I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.1 | $8.10 |
| 10 | $7.28 | $72.80 |
| 100 | $6.48 | $648.00 |
| 500 | $5.85 | $2,925.00 |
| 1,000 | $5.22 | $5,220.00 |
PIC18F2420-I/SP Overview
What is a PIC18F microcontroller? The PIC18F is a family of 8-bit CMOS flash-based microcontrollers built around an enhanced RISC instruction set designed for high-performance embedded applications. Within the broader taxonomy, the PIC18F belongs to the PIC microcontroller -> 8-bit MCU -> microcontroller (MCU) -> embedded IC -> semiconductor hierarchy. The 'F' in PIC18F denotes flash program memory with in-system programmability (ICSP), while the '2420' identifies flash/RAM/peripheral density. The 'I/SP' suffix indicates the industrial temperature range (-40C to +85C) and the SPDIP package. These devices implement nanoWatt technology for power-managed operation, which is critical for battery-powered or energy-conscious designs.
Key features of the PIC18F2420-I/SP include 25 digital I/O pins, a 10-bit analog-to-digital converter (ADC) with up to 10 channels, enhanced CCP (Capture/Compare/PWM) modules, an enhanced USART, an MSSP (Master Synchronous Serial Port) supporting SPI and I2C, and a wide operating voltage range of 4.2V to 5.5V. The device supports an internal 8 MHz oscillator, an internal 31 kHz low-power oscillator, and multiple clock modes selectable via configuration fuses, plus nanoWatt power-saving modes for sleep and idle operation.
Architecturally, the PIC18F2420 uses a 16-bit instruction word and a Harvard-style bus with separate program and data paths, achieving 200 ns instruction execution at 40 MHz. It supports hardware multiplier and 32 kHz secondary oscillator for real-time-clock applications, with priority interrupts and hardware stack. Industrial-grade operation makes it suitable for harsh environments.
Typical applications include industrial control, sensor signal conditioning, motor control (small BLDC/Stepper), USB-to-serial bridges, HVAC controls, automotive body electronics, and consumer appliance controllers. The 10-bit ADC and CCP/PWM peripherals make it ideal for closed-loop control loops where analog feedback and PWM actuation are required.
When designing with this device, use ICD/PICkit programmers for in-circuit programming and debugging, and consider the parallel master port or external memory interface carefully to avoid bus contention. Be mindful that 28-pin variants lack PORTD/PORTE-only pins available on 40/44-pin variants - some peripherals may be remapped or unavailable.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F2420-I/SP — 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 PIC18F2420-I/SP (same form factor and footprint) — differing in Package, Operating Temperature, Core, Core Architecture, Internal Oscillator.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2520-I/SP
✅ Drop-In✓ In Stock
$3.33 / Unit
View Datasheet →PIC18LF2420-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-E/SP
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →PIC18F2320-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (PIC18) |
| Program Memory | 16 KB Flash (8K x 16 words) |
| RAM | 768 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz (16 MIPS) |
| Operating Voltage | 4.2 V to 5.5 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 10 channels |
| Timers | Timer0/1/2/3 (16-bit and 8-bit) |
| Communication | Enhanced USART, MSSP (SPI/I2C) |
| PWM | Enhanced CCP (2 channels) |
| Internal Oscillator | 8 MHz + 31 kHz low-power |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-pin SPDIP (Skinny Plastic DIP, 0.300") |
| Mounting Type | Through-Hole |
PIC18F2420-I/SP Pin Configuration
| Pin 1 | MCLR/VPP/RA5 — Master Clear (reset) input / programming voltage / PORTA bit 5 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input channel 2 / ADC Vref- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input channel 3 / ADC Vref+ |
| Pin 6 | RA4/AN4/T0CKI — PORTA bit 4 / Analog input channel 4 / Timer0 clock input |
| Pin 7 | RA5/AN5/SS/LVDIN — PORTA bit 5 (also MCLR pin 1) / Analog input 5 / MSSP slave select |
| Pin 8 | OSC2/CLKOUT/RA6 — Crystal oscillator output / clock output / PORTA bit 6 |
| Pin 9 | OSC1/CLKIN/RA7 — Crystal oscillator input / clock input / PORTA bit 7 |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 PWM output |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / MSSP SPI clock / MSSP I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / MSSP SPI data in / MSSP I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / MSSP SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART asynchronous transmit / USART clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART asynchronous receive / USART data |
| Pin 18 | RB0/INT0/FLT0 — PORTB bit 0 / External interrupt 0 / PWM fault input |
| Pin 19 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 20 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 21 | RB3/INT3/CCP2 — PORTB bit 3 / External interrupt 3 / CCP2 PWM output |
| Pin 22 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 23 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 24 | RB6/PGC — PORTB bit 6 (interrupt-on-change) / ICSP clock |
| Pin 25 | RB7/PGD — PORTB bit 7 (interrupt-on-change) / ICSP data |
| Pin 26 | VSS — Ground reference |
| Pin 27 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 28 | AVDD — Analog positive supply (typically tied to VDD) |
Typical Applications
PIC18F2420-I/SP is suitable for 6 applications: Industrial Sensor Monitoring and Control, USB-to-UART Bridge and Industrial Serial Converter, Small BLDC and Stepper Motor Control, HVAC and Building Automation Controllers, Automotive Body Electronics (Non-Safety), Consumer Appliance and White-Goods Controllers.
Industrial Sensor Monitoring and Control
The PIC18F2420-I/SP is well suited for industrial sensor monitoring and control applications where its 16 KB flash holds sensor-firmware and protocol stacks while its 10-bit ADC delivers reliable conversion of analog signals from temperature, pressure, and flow sensors. The 40 MHz speed reaches 16 MIPS, enabling real-time processing of 4-20 mA or 0-10 V analog loops from industrial PLCs. 25 I/O pins interface with relays, optocouplers, and digital sensors; the 4.2-5.5 V supply matches 5V industrial rails. nanoWatt idle modes reduce standby power during periodic sampling cycles, extending battery life in remote installations where wall mains power is unavailable.
Recommended
USB-to-UART Bridge and Industrial Serial Converter
With its Enhanced USART and MSSP peripheral, the PIC18F2420-I/SP efficiently bridges UART/SPI to external interfaces. The 40 MHz throughput supports 115.2k baud comfortably for protocol conversion, while 16 KB flash fits CDC/ECC firmware stacks. 25 I/O handle handshake and flow-control lines, and 5V tolerance matches legacy industrial buses. Paired with an external USB-Serial converter IC, the PIC18F2420 realizes a robust, reprogrammable gateway for legacy RS-232/RS-485 equipment, with the 28-SPDIP package allowing through-hole assembly for serviceable field-deployable controllers.
Recommended
Small BLDC and Stepper Motor Control
The PIC18F2420-I/SP's two Enhanced CCP modules generate complementary PWM outputs for driving small brushless DC (BLDC) and stepper motors in low-cost motion applications. The 40 MIPS instruction rate is sufficient to handle Hall-sensor commutation loops and PID control algorithms for <500 W motors. The 10-bit ADC reads back-shunt current for closed-loop torque control. Through-hole SPDIP package simplifies prototyping and rework during motor-control algorithm development, making the PIC18F2420 a strong choice for fans, pumps, and small appliance motion control.
Recommended
HVAC and Building Automation Controllers
In HVAC and building automation, the PIC18F2420-I/SP captures analog inputs from temperature/humidity sensors via its 10-bit ADC and drives relays and triac controls through its 25 digital I/O pins. The 16 KB flash handles Modbus, BACnet lite, or proprietary protocol stacks, and the 768 bytes RAM supports RTOS or scheduled-task scheduling. Industrial -40C to +85C temperature operation survives rooftop or basement installation extremes. nanoWatt sleep modes cut idle consumption for battery-backed or solar-powered zone controllers, while the SPDIP-28 package suits retrofits in legacy HVAC modules.
Recommended
Automotive Body Electronics (Non-Safety)
The PIC18F2420-I/SP is well suited to non-safety automotive body electronics such as interior lighting controllers, mirror adjusters, seat-position memory, and accessory multiplex modules. The -40C to +85C industrial range handles cabin thermal environments, and the enhanced PWM modules drive LED dimming and motor-position control. 25 I/O accept switch inputs and drive MOSFET gate drivers; 16 KB flash typically suffices for CAN-Lite or LIN protocol stacks via external transceivers. Designers should note that AEC-Q100 qualified variants like PIC18F2420-I/SPVAO are required for true automotive deployments.
Recommended
Consumer Appliance and White-Goods Controllers
The PIC18F2420-I/SP powers consumer appliances including washing-machine control boards, microwave user interfaces, dishwasher control panels, and small kitchen appliances where 5 V supply rails are common and the 28-SPDIP package simplifies through-hole production at moderate volumes. The 10-bit ADC reads water-level, temperature, and motor-current sensors; 25 I/O drive 7-segment displays, keypads, triac triggers, and buzzer indicators. nanoWatt idle modes reduce standby to comply with energy regulations, and 256 bytes EEPROM store user preferences (e.g. washing cycle selection) through power cycles without battery backup.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2420-I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2520-I/SP | PIC18F2420-I/SO | PIC18LF2420-I/SP | PIC18F2320-I/SP |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SPDIP | 28-SPDIP (same) | 28-SOIC (different) | 28-SPDIP (same) | 28-SPDIP (same) |
| Program Memory (Flash) | 16 KB | 32 KB | 16 KB (same) | 16 KB (same) | 8 KB |
| RAM | 768 bytes | 1536 bytes | 768 bytes (same) | 768 bytes (same) | 512 bytes |
| EEPROM | 256 bytes | 256 bytes (same) | 256 bytes (same) | 256 bytes (same) | 256 bytes (same) |
| Maximum Clock Speed | 40 MHz (16 MIPS) | 40 MHz (16 MIPS, same) | 40 MHz (16 MIPS, same) | 40 MHz (16 MIPS, same) | 40 MHz (16 MIPS, same) |
| Operating Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V (same) | 4.2 V to 5.5 V (same) | 1.8 V to 3.6 V (different) | 4.2 V to 5.5 V (same) |
| I/O Pins | 25 | 25 (same) | 25 (same) | 25 (same) | 25 (same) |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (same) | -40C to +85C (same) | -40C to +85C (same) | -40C to +85C (same) |
| Unit Price (qty 100) | $6.48 | ~$7.20 (higher mem) | ~$6.48 (same) | ~$7.00 (LF premium) | ~$5.95 (lower mem) |
Key Differentiators
- Larger flash vs PIC18F2320 for cost-effective mid-range firmware (vs PIC18F2320-I/SP)
- Drop-in upgrade to PIC18F2520 for memory growth (vs PIC18F2520-I/SP)
- Industrial-grade SPDIP for easy prototyping and field replacement (vs PIC18F2420-I/ML (QFN variant))
Design Notes
Place a 100 nF decoupling capacitor as close as possible to the VDD/AVDD pins (27/28) and a bulk capacitor (e.g. 10 uF) at the regulator output. The PIC18F2420 can draw peak currents up to 200 mA when all peripherals are active at 40 MHz; for low-noise applications add a ferrite bead between VDD and AVDD.
Keep the crystal/oscillator traces short (<10 mm) and guard-ground them. MCLR pin (1) requires a 10 kohm pull-up and a 100 nF to ground for reliable reset; design the ICSP connector so that the PGC/PGD lines are not loaded by external circuitry during programming.
Do not exceed 5.5 V on VDD - this is a 5V-only part. For lower voltage, use the LF variant. Always configure the ADC channel using the ADCON1 register before analog reads; using PORTB weak pull-ups with input pins configured as analog disables the pull-up. Reading PORTB requires the LAT/port mismatch pattern in newer PIC18 silicon revisions.
Compliance Information
RoHS/REACH compliant per Microchip material declarations. Industrial-grade temperature range -40C to +85C. AEC-Q100 qualification NOT held for this part - choose PIC18F2420-I/SPVAO variant for automotive deployments.
