PIC18F2420-E/SO - 8-bit 25MHz 16KB Flash MCU 28-SOIC | Microchip
MPN: PIC18F2420-E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.97 | $497.00 |
| 500 | $4.45 | $2,225.00 |
| 1,000 | $3.93 | $3,930.00 |
PIC18F2420-E/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), data memory (RAM), non-volatile storage (EEPROM), and programmable I/O peripherals. The PIC18 family is Microchip's 8-bit high-performance family featuring an enhanced instruction set, hardware multiplier, and nanoWatt power management. MCUs sit at the top of the embedded computing hierarchy: transistor -> logic gate -> register/ALU -> CPU core -> microcontroller -> embedded system -> IoT device.
Key features of the PIC18F2420-E/SO include 25 I/O pins, a 10-bit ADC with up to 10 channels, two 8-bit and three 16-bit timers, two USART modules, an SPI/I2C MSSP peripheral, a 2.0V-5.5V operating voltage range (the "LF" variant offers 2.0V-5.5V down to 2.0V), an internal 8 MHz oscillator with PLL support, nanoWatt technology for ultra-low sleep currents, ICSP in-circuit serial programming, and a 10-year Flash/EEPRETENTION specification. The 28-pin SOIC footprint is JEDEC-standard and is widely supported by hand-soldered prototyping and automated SMT lines.
Architecturally the PIC18F2420 uses a Harvard RISC architecture with separate program and data buses, a hardware 8x8 multiplier, and a 16-bit instruction word. Its enhanced instruction set provides C-friendly addressing with indirect/FSR pointers and table reads for efficient compiler code generation, while nanoWatt modes (Run, Idle, Sleep, and RTCC from Timer1) allow microamp-level standby current for battery-powered designs.
Typical applications include industrial control and sensor nodes, automotive body and HVAC modules, consumer white-goods user interfaces, USB-to-UART bridge firmware on legacy PIC hardware, and battery-powered instrumentation. The extended -40C to +125C temperature range supports under-hood automotive and outdoor industrial deployments.
When designing with this part, ensure the ICSP programming pins (RB6, RB7) and MCLR are accessible for production programming, and note that E vs I temperature grade is an orderable suffix (E = -40C to +125C, I = -40C to +85C), not a firmware option.
This page synthesizes distributor pricing, drop-in alternative MPNs, and practical design considerations not found in the standalone Microchip datasheet.
Drop-in alternatives for PIC18F2420-E/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 PIC18F2420-E/SO (same form factor and footprint) — differing in Package, Timers, Operating Temperature, Core Architecture, Internal Oscillator.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2420-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2520-E/SO
✅ Drop-In✓ In Stock
$4.6 / Unit
View Datasheet →PIC18F2420T-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-E/SP
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →PIC18F2420-I/SP
✅ Drop-In✓ In Stock
$5.22 / Unit
View Datasheet →PIC18F23K20-I/SO
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC18F23K22-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-E/SO Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| CPU Speed | 25 MIPS (40 MHz max oscillator) |
| Program Memory | 16 KB Flash (8K x 16) |
| Data RAM | 768 bytes |
| EEPROM | 256 bytes |
| I/O Pins | 25 |
| ADC | 10-bit, up to 10 channels |
| Timers | 2 x 8-bit, 3 x 16-bit |
| Communication Peripherals | 2 x USART (EUSART), 1 x MSSP (SPI / I2C) |
| Operating Voltage | 4.2 V to 5.5 V |
| Operating Temperature | -40C to +125C (E suffix) |
| Package | 28-pin SOIC (300 mil) |
| Mounting Type | Surface Mount |
| Internal Oscillator | 8 MHz with PLL |
| ICSP | Yes (In-Circuit Serial Programming) |
| Watchdog Timer | Yes (WDT with on-chip low-power oscillator) |
| Brown-out Reset | Yes (BOR) |
| Power-Saving Modes | Run / Idle / Sleep (nanoWatt) |
| RoHS Status | Compliant |
PIC18F2420-E/SO Pin Configuration
| Pin 1 | MCLR/VPP/RA5 — Master Clear (reset) input or 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 negative reference |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input channel 3 / ADC positive reference |
| Pin 6 | RA4/TOCKI — PORTA bit 4 / Timer0 clock input (open-drain) |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI slave select |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI/RA7 — Oscillator crystal input / external clock input / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — Oscillator crystal 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 PWM output |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM 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 async transmit or sync clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / EUSART async receive or sync data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 21 | RB0/INT0/AN12 — PORTB bit 0 / External interrupt 0 / Analog input channel 12 |
| Pin 22 | RB1/INT1/AN10 — PORTB bit 1 / External interrupt 1 / Analog input channel 10 |
| Pin 23 | RB2/INT2/AN8 — PORTB bit 2 / External interrupt 2 / Analog input channel 8 |
| Pin 24 | RB3/AN9/CCP2 — PORTB bit 3 / Analog input channel 9 / CCP2 PWM output |
| Pin 25 | RB4/KBI0/AN11 — PORTB bit 4 / Interrupt-on-change bit 0 / Analog input channel 11 |
| Pin 26 | RB5/KBI1/PGM — PORTB bit 5 / Interrupt-on-change bit 1 / LVP programming |
| Pin 27 | RB6/KBI2/PGC — PORTB bit 6 / Interrupt-on-change bit 2 / ICSP clock |
| Pin 28 | RB7/KBI3/PGD — PORTB bit 7 / Interrupt-on-change bit 3 / ICSP data |
Typical Applications
PIC18F2420-E/SO is suitable for 7 applications: Industrial Sensor Interface Module, Automotive Body and HVAC Controller, Battery-Powered Data Logger, USB-to-UART Bridge Firmware, White-Goods User Interface Board, IoT Sensor Node with UART Connectivity, Consumer Remote Control and HMI.
Industrial Sensor Interface Module
The PIC18F2420-E/SO is a strong fit for industrial sensor interface modules thanks to its 10-channel 10-bit ADC, 25 I/O pins, and 4.2 V to 5.5 V operating range that tolerates 24 V industrial rails after regulation. The -40C to +125C extended temperature grade supports outdoor enclosures, factory floors, and motor-control cabinets. The dual EUSART interfaces allow simultaneous connection to an RS-485 sensor bus and a debug UART, while the MSSP peripheral handles I2C sensor clusters or SPI ADC chains.
Recommended
Automotive Body and HVAC Controller
The PIC18F2420-E/SO is widely deployed in non-safety automotive body controllers and HVAC modules because its -40C to +125C grade matches cabin and under-hood thermal stress. The 16 KB Flash comfortably fits typical HVAC state-machine code, and the two PWM/CCP channels drive blower and mode-door actuators. nanoWatt Sleep mode below 100 nA minimizes quiescent drain when the vehicle is parked. For airbag, ABS, or ADAS systems, however, an AEC-Q100-qualified PIC18F46K22-I/PT is required instead.
Recommended
Battery-Powered Data Logger
The PIC18F2420-E/SO suits battery-powered data loggers because Sleep current below 100 nA and nanoWatt Run/Idle modes minimize energy budget between samples. The 256-byte EEPROM stores calibration constants without wearing Flash, and the RTCC (Real-Time Clock and Calendar) module timestamps each measurement while the CPU sleeps. The internal 8 MHz oscillator with 4x PLL eliminates an external crystal on cost-sensitive designs. Two AA cells through a boost regulator supply 3.3 V to VDD for multi-year deployment.
Recommended
USB-to-UART Bridge Firmware
The PIC18F2420-E/SO hosts legacy USB-to-UART bridge firmware using the MSSP peripheral as SPI master for an external USB controller such as the MCP2200, while the EUSART talks to the host MCU. With 16 KB Flash and 768 bytes RAM, this part comfortably fits a USB CDC stack, command parser, and bootloader. ICSP via RB6/RB7 enables in-field firmware updates through the same header used for serial bridging. For new designs the PIC18F14K50 has integrated USB but only 14 KB Flash.
Recommended
White-Goods User Interface Board
The PIC18F2420-E/SO is a cost-effective microcontroller for white-goods user interfaces such as washing-machine control panels, dishwasher keypads, and refrigerator displays. Its 25 I/O pins drive 7-segment displays, capacitive touch buttons via the CTMU peripheral, and buzzer/relay outputs. The 10-bit ADC reads temperature sensors and water-level probes without external converters. The -40C to +125C grade survives the thermal stress of oven-adjacent enclosures and steam-laden dishwasher interiors.
Recommended
IoT Sensor Node with UART Connectivity
The PIC18F2420-E/SO serves as the MCU in IoT sensor nodes that communicate over UART-attached Wi-Fi or cellular modules such as the ESP8266 or SIM800L. The MSSP peripheral handles I2C sensors, while the EUSART delivers AT-command frames to the radio module. With nanoWatt Sleep below 100 nA and a wake-on-RTCC alarm, the part enables years of battery life on two AA cells. The 16 KB Flash fits lightweight MQTT-SN or CoAP client stacks for sub-1kB payloads.
Recommended
Consumer Remote Control and HMI
The PIC18F2420-E/SO drives consumer remote controls and small HMIs thanks to its low Sleep current, ICSP for easy in-line programming, and integrated CCP/PWM for LED backlight dimming or IR carrier generation. The 10-bit ADC reads potentiometers, while the MSSP peripheral drives SPI OLED displays or I2C key-scan expanders. The 28-SOIC footprint fits slim handheld enclosures, and the -40C to +125C grade covers automotive and outdoor use cases. Code size up to 16 KB comfortably fits menu trees and IR protocol libraries.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2420-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2420-I/SO | PIC18F2520-E/SO | PIC18F2420T-E/SO | PIC18F23K20-I/SO | PIC18F23K22-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (300 mil) | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same |
| Flash Program Memory | 16 KB | 16 KB | 32 KB | 16 KB | 8 KB | 8 KB |
| RAM | 768 bytes | 768 bytes | 1536 bytes | 768 bytes | 512 bytes | 512 bytes |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Operating 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 | 1.8 V to 3.6 V | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +125C | -40C to +85C | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +85C |
| I/O Pins | 25 | 25 | 25 | 25 | 25 | 25 |
| ADC | 10-bit, 10 channels | 10-bit, 10 channels | 10-bit, 10 channels | 10-bit, 10 channels | 10-bit, 8 channels | 10-bit, 17 channels |
| Approx. Unit Price (USD) | 6.20 (qty 1) | 5.80 (qty 1) | 6.50 (qty 1) | 6.20 (qty 1) | 3.50 (qty 1) | 3.80 (qty 1) |
Key Differentiators
- Highest memory density in 28-SOIC family at this price point (vs PIC18F23K20-I/SO)
- True 5V operation with industrial peripherals (vs PIC18F23K22-I/SO)
- Extended -40C to +125C temperature grade available (vs PIC18F2420-I/SO)
- Double the Flash when you upgrade to PIC18F2520 in the same package (vs PIC18F2520-E/SO)
Design Notes
Keep the ICSP footprint accessible: route PGC (RB6) and PGD (RB7) to a 6-pin header even in production designs, since firmware updates and recall repairs are vastly cheaper with ICSP than with socket swaps. Decouple VDD with a 100 nF X7R ceramic placed within 5 mm of pin 20, and place a bulk 10 uF tantalum or aluminum polymer within 25 mm. Ground returns should be a solid pour connected to VSS at pins 8 and 19 with multiple vias to minimize switching noise coupling into the ADC.
Use nanoWatt Sleep mode aggressively in battery-powered designs: the PIC18F2420-E/SO draws less than 100 nA typical with WDT disabled. Configure the RTCC to wake the part every minute, perform the ADC conversion, write EEPROM if needed, and return to Sleep. Estimated battery life at one wake per minute with average 1 mA active draw and 768 bytes RAM retention is approximately 3 years on 2 x AA alkaline cells (2500 mAh), assuming regulator quiescent current stays below 10 uA.
Do not confuse the E and I temperature grades - the E suffix is -40C to +125C extended, and the I suffix is -40C to +85C industrial. Both share the same silicon but the test program differs. Also note that the standard F (Flash) variant operates at 4.2 V to 5.5 V; if your design uses a 3.3 V rail, choose the PIC18LF2420 (2.0 V to 5.5 V) instead. Programming voltage on MCLR/VPP is 13.4 V typical for high-voltage ICSP, but low-voltage ICSP at 5 V via PGM is supported for in-circuit updates without 13 V rails.
When using the ADC for high-impedance sensors, add a 100 nF X7R bypass cap directly on the analog input pin to form an RC filter with the source impedance, and choose a conversion clock slow enough that the acquisition time (Tacq) exceeds the source's settling time. For 10 kohm source impedances, use Tacq greater than 7.5 us. Keep analog traces short and away from RB6/RB7 ICSP switching to avoid ADC noise coupling during programming events. Use the FVR (Fixed Voltage Reference) module for ratiometric measurements on VDD-sensitive sensors.
Compliance Information
RoHS and REACH compliant per Microchip product page. The PIC18F2420 family is NOT AEC-Q100 qualified - choose PIC18F46K22-I/PT for automotive safety applications.
