PIC18F2420-E/ML - 8-bit PIC MCU, 16KB Flash, 25MHz, 28-QFN | Microchip
MPN: PIC18F2420-E/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.65 | $46.50 |
| 100 | $4.1 | $410.00 |
| 500 | $3.65 | $1,825.00 |
| 1,000 | $3.2 | $3,200.00 |
PIC18F2420-E/ML Overview
A microcontroller (MCU) is an integrated circuit that combines a CPU core, non-volatile program memory, working RAM, and configurable peripherals on a single silicon die. PIC18F-series devices from Microchip are 8-bit Harvard-architecture microcontrollers optimized for deterministic real-time control and low-power embedded applications. They sit within the broader category hierarchy of microcontroller -> embedded processor -> semiconductor IC, and are commonly programmed in C through Microchip's MPLAB X IDE and XC8 toolchain.
Key features of the PIC18F2420-E/ML include 25 I/O pins, hardware USART, MSSP (SPI/I2C) ports, 10-bit ADC with 10 channels, two analog comparators, four timer modules, and nanoWatt technology for sleep currents under 1 uA. The PIC18 CPU core provides 75 instructions with 16-bit instruction width and 8-bit data path, enabling efficient C-code generation. The internal oscillator block supports 31 kHz to 8 MHz operation without external crystals.
Architecturally, the PIC18F2420 uses a RISC core with separate program and data buses (Harvard architecture), allowing simultaneous instruction fetch and data access. The Flash program memory supports self-programming for in-field firmware updates, and the 256-byte data EEPROM is rated for 1 million erase/write cycles. The fail-safe clock monitor allows safe system shutdown if the primary clock source fails, an important feature for automotive and industrial safety applications.
Typical applications include industrial control systems, sensor interface modules, low-power remote sensor nodes, consumer appliance controls, USB-to-UART bridges, and general-purpose embedded control. The wide operating voltage (4.2 V to 5.5 V) and extended temperature range suit 24V industrial bus systems with onboard regulation.
When designing with the PIC18F2420-E/ML, ensure decoupling capacitors (typically 100 nF and 10 uF) are placed within 5 mm of VDD pins. The 28-QFN package requires thermal pad soldering to a PCB ground plane for proper thermal and electrical performance. Programming is performed via ICSP using Microchip's PICkit 5, ICD 4, or MPLAB Snap debuggers.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC18F2420-E/ML — 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/ML (same form factor and footprint) — differing in Package, Program Memory (Flash), ADC, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2520-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/ML
✅ Drop-In✓ In Stock
$4.25 / Unit
View Datasheet →PIC18F23K22-E/ML
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC18F4420-E/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F2420-E/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data SRAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Maximum Clock Frequency | 40 MHz (10 MIPS) |
| Operating Voltage (VDD) | 4.2 V to 5.5 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 10 channels |
| Timers | 4 (Timer0/1/2/3) |
| Communication | 1x USART (EUSART), 1x MSSP (SPI/I2C) |
| Analog Comparators | 2 |
| Package | 28-QFN (6x6 mm) |
| Operating Temperature | -40C to +125C (Extended, 'E' suffix) |
| Internal Oscillator | 31 kHz to 8 MHz |
| Hardware Multiplier | 8 x 8 single-cycle |
| Watchdog Timer | Yes, with dedicated RC oscillator |
| Fail-Safe Clock Monitor | Yes |
| Instruction Set | 75 instructions, 16-bit wide |
| MSL Level | 3 (168 hours) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F2420-E/ML Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear reset input / programming voltage / PORTE bit 3 |
| 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/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 — Crystal oscillator input / external clock / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / PORTA bit 6 |
| Pin 11 | RC0/T1OSO/T1CKI — 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 / USART transmit / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.2 V to 5.5 V) |
| Pin 21 | RB0/INT0/FLT0 — PORTB bit 0 / External interrupt 0 / PWM fault input |
| Pin 22 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 23 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 24 | RB3/INT3/CCP2 — PORTB bit 3 / External interrupt 3 / CCP2 |
| Pin 25 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 26 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18F2420-E/ML is suitable for 6 applications: Industrial Sensor Interface Module, Consumer Appliance Control Board, Low-Power Remote Sensor Node, Automotive Interior Lighting Controller, USB-to-UART Communication Bridge, Educational and Hobbyist Development Platform.
Industrial Sensor Interface Module
The PIC18F2420-E/ML serves as an industrial sensor hub reading 4-20 mA analog inputs, RTD temperature sensors, and digital switch signals. Its 10-bit ADC with 10 channels digitizes up to 10 sensor inputs simultaneously, while the 25 I/O pins drive relays, optocouplers, and status LEDs. The extended -40C to +125C temperature grade (E suffix) and 4.2V to 5.5V operation suit 24V industrial backplane systems with onboard 5V regulation. nanoWatt technology reduces sleep current under 1 uA for battery-backed sensor nodes, and the fail-safe clock monitor provides automatic recovery from primary oscillator faults in unattended installations.
Recommended
Consumer Appliance Control Board
The PIC18F2420-E/ML controls washing machines, dishwashers, microwave ovens, and HVAC control panels where its 8-bit PIC core delivers deterministic real-time response for keypad scanning, PWM-driven motor control, and seven-segment display multiplexing. The hardware 8x8 multiplier accelerates control-loop math for proportional-integral-derivative (PID) regulation of fan speeds and temperature. The 256-byte EEPROM stores user-set preferences across power cycles, while the integrated USART enables diagnostics via RS-485 or UART-to-Bluetooth bridge modules. The 28-QFN package fits compact control board layouts.
Recommended
Low-Power Remote Sensor Node
Battery-powered wireless sensor nodes benefit from the PIC18F2420-E/ML's nanoWatt power-managed modes, where Sleep mode current drops under 1 uA with the real-time clock and Watchdog Timer remaining active for scheduled wake-ups. The internal 31 kHz to 8 MHz oscillator eliminates external crystal draw, and the USART or MSSP interface connects directly to 2.4 GHz transceivers such as the MRF24J40 or low-power Sub-GHz modules. The 256-byte EEPROM stores calibration constants and sensor IDs, while the 768-byte SRAM buffers measurement packets before radio transmission.
Recommended
Automotive Interior Lighting Controller
The PIC18F2420-E/ML drives LED strings, RGB ambient lighting, and PWM dimming channels in automotive interior applications. Its 10-bit ADC reads cabin light sensors for automatic dimming, while the four hardware timers generate independent PWM frequencies for multi-zone lighting control. The extended -40C to +125C temperature grade meets automotive cabin and under-hood environmental requirements, though the PIC18F2420-E/ML is not AEC-Q100 qualified - for safety-critical or powertrain applications, choose AEC-Q100 qualified variants. The hardware USART interfaces with body control modules via LIN or CAN bus transceivers.
Recommended
USB-to-UART Communication Bridge
The PIC18F2420-E/ML operates as a USB-to-UART bridge (with external USB interface IC), translating between legacy RS-232 equipment and modern USB hosts. The hardware USART provides full-duplex asynchronous communication at up to 5 Mbps, while the MSSP (SPI/I2C) port handles auxiliary configuration EEPROM. The 16 KB Flash accommodates USB HID or CDC class firmware plus custom protocol translation, and the 768-byte SRAM buffers full-speed USB packets. The 28-QFN package enables compact dongle form factors.
Recommended
Educational and Hobbyist Development Platform
The PIC18F2420-E/ML serves as a teaching platform for embedded systems courses, where students learn C programming, register-level peripheral configuration, and real-time control fundamentals. The PICkit 5 or ICD 4 in-circuit debugger connects via the ICSP interface to provide single-step debugging and breakpoint support, and the MPLAB X IDE with XC8 compiler offers a free, full-featured development environment. The PIC18F core's 75-instruction RISC architecture is approachable for beginners while supporting advanced topics like interrupts, DMA, and low-power design.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2420-E/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2520-E/ML | PIC18F2420-I/ML | PIC18F23K22-E/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (6x6 mm) | 28-QFN (6x6 mm) - same | 28-QFN (6x6 mm) - same | 28-QFN (6x6 mm) - same |
| Flash Program Memory | 16 KB | 32 KB | 16 KB | 8 KB |
| SRAM | 768 bytes | 1536 bytes | 768 bytes | 512 bytes |
| Data EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Max Clock Frequency | 25 MHz (E grade) | 40 MHz | 40 MHz | 64 MHz |
| ADC Resolution | 10-bit | 10-bit | 10-bit | 12-bit |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +125C |
Key Differentiators
- Larger Flash and SRAM than PIC18F23K22 (vs PIC18F23K22-E/ML)
- Established mature product line (vs PIC18F23K22-E/ML)
- Extended temperature grade availability (vs PIC18F2420-I/ML)
Design Notes
The PIC18F2420-E/ML requires a bulk decoupling capacitor of at least 10 uF tantalum or ceramic plus a 100 nF high-frequency ceramic placed within 5 mm of each VDD/VSS pin pair. The 28-QFN package has a single VDD pin (pin 20) and two VSS pins (pins 8 and 19), so multiple decoupling locations are needed to suppress switching transients during PWM and ADC sampling events. For noise-sensitive analog measurements, add a ferrite bead on the analog supply rail feeding the AVdd/AVss pair.
Estimated: At maximum operating frequency of 40 MHz and 5.5 V supply, the PIC18F2420 core current consumption is approximately 16 mA, yielding 88 mW dissipation. The 28-QFN (6x6 mm) package has typical theta_JA around 30 C/W on a 1 oz copper 4-layer PCB, resulting in a junction temperature rise of 2.6 C above ambient. At 125 C ambient industrial operation, this keeps the junction within the 150 C maximum rating. The exposed thermal pad must be soldered to the PCB ground plane for proper thermal dissipation.
The 28-QFN (6x6 mm) package has 0.65 mm pitch with a central thermal pad. Per IPC-7351 guidelines, the land pattern requires NSMD (non-solder mask defined) pads with 0.30 mm pad width and 0.35 mm solder mask opening for reliable paste stencil printing. The central thermal pad (approximately 4.0 x 4.0 mm) should have thermal vias in a 3x3 grid of 0.3 mm drilled holes to the inner ground plane for heat dissipation. Place the ICSP header (PGC/PGD/MCLR/VSS/VDD) at the board edge for in-circuit programming access.
Avoid leaving the MCLR pin floating - it requires a 10 kohm pull-up to VDD for proper device reset. When using the internal oscillator, the FAIL-SAFE clock monitor must be enabled in CONFIG1H to provide automatic switchover to the internal RC if the primary oscillator fails. For ADC accuracy, the acquisition time must be calculated based on source impedance (typically 5 us minimum for 10-bit mode at 5 V). The CONFIG words must be programmed correctly; otherwise the device may enter an unprogrammed state on reset.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - for automotive safety-critical applications, choose AEC-Q100-qualified variants such as PIC18F46K22-I/PT or PIC18F25K50-I/ML.
