PIC18F2420-I/ML - 8-bit 40MHz 16KB Flash MCU | Microchip
MPN: PIC18F2420-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.4 | $6.40 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.7 | $2,350.00 |
| 1,000 | $4.25 | $4,250.00 |
PIC18F2420-I/ML Overview
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a self-contained single-chip computer that integrates an 8-bit CPU core, non-volatile program memory (Flash or ROM), volatile data memory (SRAM), on-chip peripherals, and an execution engine into one package. The PIC18 family sits within Microchip's PIC microcontroller taxonomy: 8-bit MCU -> PIC microcontroller -> PIC18 family -> PIC18F2420 sub-family, occupying the high-performance mid-range tier with nanoWatt Technology power management.
Key specifications include operation from 2.0 V to 5.5 V across the industrial -40C to +85C range, 25 digital I/O pins, a 10-bit ADC with up to 10 input channels, two 8-bit timers plus three 16-bit timers, two capture/compare/PWM (CCP) modules, an enhanced USART (EUSART), an MSSP module supporting SPI and I2C (master and slave), and nanoWatt Technology for low-power operation. The enhanced flash program memory supports 100,000 erase/write cycles typical and data retention exceeding 40 years.
The PIC18F2420 is built on an enhanced Harvard architecture that separates program and data buses for parallel fetch and execution. Microchip's nanoWatt Technology provides multiple software-selectable power-management modes (Run, Idle, and Sleep) plus an ultra-low-power wake-up from sleep on interrupt, while the wide 2.0 V to 5.5 V operating range allows direct connection to single-cell Li-ion or three-cell alkaline supplies without external regulation.
Typical applications include consumer-electronic user interfaces, industrial sensor and instrumentation nodes, low-end motor-control loops, USB-to-UART bridges (with an external transceiver), and remote-control subsystems. The combination of 16 KB Flash, 768 byte SRAM and 25 I/O makes the device a sweet-spot choice for cost-sensitive embedded designs that need more headroom than an 8-bit mid-range part like PIC16 but do not need a 16-bit dsPIC or 32-bit MCU.
When designing with this device, ensure your toolchain matches the ICSP programming mode shipped on the silicon and include adequate Vcap decoupling near the core supply pin per datasheet guidance. For multi-rail designs, place decoupling capacitors within 5 mm of each Vdd/Vss pair to keep switching noise out of the sensitive analog reference.
This page synthesizes distributor pricing, drop-in 28-QFN alternatives drawn from the PIC18 family, and practical design notes that complement the Microchip datasheet.
Drop-in alternatives for PIC18F2420-I/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-I/ML (same form factor and footprint) — differing in Core Architecture, Package, Timers, Program Memory (Flash), ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F2420-E/ML
✅ Drop-In✓ In Stock
$3.2 / Unit
View Datasheet →PIC18F2520-I/ML
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F2320-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 (enhanced Harvard) |
| Maximum CPU Frequency | 40 MHz |
| Program Memory (Flash) | 16 KB (8K x 16 words) |
| Data Memory (SRAM) | 768 bytes |
| Data EEPROM | 256 bytes |
| Operating Voltage Range | 2.0 V to 5.5 V |
| Operating Temperature Range | -40C to +85C (industrial) |
| Digital I/O Pins | 25 |
| ADC | 10-bit, up to 10 channels |
| Timers | 2 x 8-bit, 3 x 16-bit |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | EUSART, MSSP (SPI/I2C master+slave) |
| Package | 28-QFN (6 mm x 6 mm), designation /ML |
| Mounting Type | Surface Mount |
| Power Management | nanoWatt Technology (Run/Idle/Sleep modes) |
| Flash Endurance | 100,000 erase/write cycles typical |
| RoHS Status | Compliant |
PIC18F2420-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 3 | RA2/AN2/VREF- — PORTA bit 2 / Analog input channel 2 / ADC reference negative |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input channel 3 / ADC reference positive |
| Pin 5 | RA4/T0CKI — PORTA bit 4 (open-drain) / Timer 0 clock input |
| Pin 6 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI slave select |
| Pin 7 | RA6/OSC2 — PORTA bit 6 / Crystal oscillator output |
| Pin 8 | RA7/OSC1 — PORTA bit 7 / Crystal oscillator input |
| Pin 9 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 10 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 11 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 12 | RB3/CCP2 — PORTB bit 3 / Capture/Compare/PWM 2 |
| Pin 13 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 14 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 15 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 16 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 17 | Vss — Ground reference |
| Pin 18 | VDD — Positive supply voltage |
| Pin 19 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer 1 oscillator output / clock input |
| Pin 20 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer 1 oscillator input / CCP2 alt |
| Pin 21 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 22 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| 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 / EUSART TX / clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / EUSART RX / data |
| Pin 27 | VSS — Ground reference |
| Pin 28 | VDD — Positive supply voltage |
Typical Applications
PIC18F2420-I/ML is suitable for 6 applications: Consumer Electronics User Interface, Industrial Sensor Node, Low-End Motor Control Loop, USB-to-UART Bridge, Remote Control Subsystem, Battery-Powered Data Logger.
Consumer Electronics User Interface
The PIC18F2420-I/ML drives consumer-electronics user interfaces such as appliance front panels, remote controls, and small HMI modules. With 25 digital I/O pins and 16 KB Flash, the part provides enough code headroom for menu state machines and key-debounce logic. The 2.0 V to 5.5 V operating range accepts three-cell alkaline or single-cell Li-ion supply rails directly. nanoWatt Technology sleep mode drops quiescent current to microamp range during standby, preserving battery life. Place 0.1 uF decoupling on each Vdd/Vss pair near the 28-QFN pins to keep switching transients out of the analog reference used for keypad scanning.
Recommended
Industrial Sensor Node
In industrial sensor nodes, the PIC18F2420-I/ML reads 4-20 mA or 0-10 V analog transducers through its 10-bit ADC with up to 10 channels. The 40 MHz core provides 10 MIPS, sufficient for digital filtering and MODBUS framing, while the EUSART handles RS-485 links. The industrial -40C to +85C operating range matches factory-floor environmental specs without derating. Use the MSSP module for SPI sensor chains or I2C EEPROM data logging. Verify that input protection (TVS) and common-mode chokes are placed close to the connector per datasheet EMC guidance.
Recommended
Low-End Motor Control Loop
The PIC18F2420-I/ML closes simple brushless DC or stepper motor control loops using its two CCP modules for PWM generation and its 10-bit ADC for back-EMF or current sensing. nanoWalt Technology's Idle mode plus Sleep wake-up on interrupt allows efficient PWM-driven commutation at low duty cycles. The 25 available I/O pins multiplex hall-sensor inputs, gate-driver signals, and a fault input comfortably. For applications needing finer PWM resolution, the PIC18F23K22-I/ML in the same 28-QFN footprint offers HF PWM and 64 MHz operation.
Recommended
USB-to-UART Bridge
The PIC18F2420-I/ML implements a USB-to-UART bridge when paired with an external USB transceiver such as the MCP2200 or FT232-style companion IC. The on-chip EUSART handles the UART side at standard baud rates up to 1 Mbps, while firmware manages USB enumeration and class-compliant COM-port framing. The exposed-pad 28-QFN package dissipates heat efficiently for continuous streaming at high duty cycle. Add a 1 uF tantalum plus 0.1 uF ceramic bulk decoupling bank near the Vdd pins to handle USB inrush events cleanly.
Recommended
Remote Control Subsystem
For IR or RF remote control subsystems, the PIC18F2420-I/ML generates 38 kHz carrier PWM through one CCP module while the EUSART handles Manchester-coded RF transceivers. Its 16 KB Flash holds IR/RF protocol stacks (RC5, NEC, or proprietary) plus learn-mode state machines. Wake-up from Sleep on interrupt pulls the MCU out of nanoWatt mode on a button press, saving battery between keystrokes. Match the 16 KB Flash to selected protocols carefully; the PIC18F2520-I/ML offers 32 KB for multi-protocol remotes in the same footprint.
Recommended
Battery-Powered Data Logger
The PIC18F2420-I/ML powers battery-operated data loggers that sample sensors and write time-stamped records to an external I2C EEPROM or SPI FRAM. 768 bytes of SRAM double-buffer batch writes while the Flash holds compression and timestamp logic. nanoWatt Technology's Sleep mode draws less than 1 uA typical, enabling multi-year operation on a single CR2032 cell when sleep dominates the duty cycle. Select the PIC18F2420-E/ML for outdoor deployments exposed to -40C to +125C ranges per Microchip extended-temperature specs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F2420-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F2420-E/ML | PIC18F2520-I/ML | PIC18F2320-I/ML |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (ML) 6x6 mm | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same |
| Program Flash | 16 KB | 16 KB (same) | 32 KB (+100%) | 8 KB (-50%) |
| SRAM | 768 bytes | 768 bytes (same) | 1536 bytes (+100%) | 512 bytes (-33%) |
| EEPROM | 256 bytes | 256 bytes (same) | 256 bytes (same) | 256 bytes (same) |
| Maximum CPU Frequency | 40 MHz | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) |
| Operating Temperature | -40C to +85C (I) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) |
| Price (1000 pcs, USD) | 4.25 | 4.40 (est.) | 5.10 (est.) | 3.80 (est.) |
Key Differentiators
- Balanced Flash/SRAM in 28-QFN with nanoWalt Sleep (vs PIC18F2320-I/ML)
- Smaller 6 mm x 6 mm footprint than DIP equivalents (vs PIC18F2420-I/SP (28-SPDIP))
- Industrial-grade -I temperature option matches typical factory use (vs PIC18F2420-E/ML)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of each Vdd/Vss pin pair on the PIC18F2420-I/ML 28-QFN. Add a bulk 1 uF to 10 uF tantalum or ceramic cap on the main Vdd rail. nanoWatt Technology's Sleep mode drops Iq to less than 1 uA typical; use software-controlled Idle or Sleep plus interrupt wake-up to maximize battery life for remote-control and IoT-sensor applications.
The 28-QFN (ML) package exposes a thermal pad on the underside that MUST be soldered to a grounded copper pour for mechanical reliability and thermal dissipation. The PCB land pattern should follow Microchip's 28-QFN (ML) recommended footprint with NSMD pads and a 0.3 mm to 0.4 mm solder-mask expansion. Estimated: with a 1 sq inch 2-oz copper pour the theta_JA is approximately 30 C/W enabling 1W dissipation at industrial temperatures without derating.
Do not confuse the PIC18F2420-I/ML (/ML = 28-QFN) with PIC18F2420-I/SP (/SP = 28-SPDIP) - both share the silicon die but require different PCB footprints and prototype tooling. Configure ICSP clock and data on RB6/RB7 (PGC/PGD) per datasheet programming spec; ensure PGC and PGD traces are short and isolated from high-current switching nodes. Verified only on datasheet recommendation; production users should add ESD protection diodes and a 10 kohm pull-up on MCLR to avoid programming faults.
For ADC accuracy on the PIC18F2420-I/ML, route analog RA0-RA5 traces away from digital switching nodes and add a small RC filter (10 ohm + 100 nF) on heavily-loaded analog inputs. Use AVdd as a separate filtered rail decoupled with 10 uF + 0.1 uF if the application demands better than 1 LSB ADC noise. The 10-bit ADC reference can be internal or external via RA3/VREF+ and RA2/VREF-.
Compliance Information
RoHS compliance per Microchip product page and DigiKey listing. Industrial -40C to +85C grade (not automotive AEC-Q100).
