PIC18LF2420-I/SO - 8-bit 40MHz MCU 16KB Flash 28-SOIC | Microchip
MPN: PIC18LF2420-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $3 | $1,500.00 |
| 1,000 | $2.71 | $2,710.00 |
PIC18LF2420-I/SO Overview
What is a PIC18 microcontroller? PIC18 is Microchip's enhanced 8-bit RISC core family, evolving the baseline PIC16 architecture with a 16-bit instruction word, linear memory addressing, hardware multiplier, prioritized interrupts and C-friendly compiler support. As 8-bit MCUs, PIC18 parts sit in the broader taxonomy of microcontroller -> embedded controller -> semiconductor device, and the LF sub-family specifically targets battery-friendly designs through nanoWatt power-saving modes. The architecture's deterministic single-cycle instruction execution makes PIC18 well-suited for real-time control loops where predictable latency matters more than raw throughput.
Key differentiating features of the PIC18LF2420-I/SO include the 2.0 V to 5.5 V operating range with full peripheral operation across the band, 10-bit ADC with up to 13 input channels sharing package pins, internal oscillator options selectable via configuration fuses, and nanoWatt idle/sleep modes that drop core current to the microampere range. The 28-SOIC industrial-temperature grade (-40C to +85C, denoted by the I suffix) supports harsh-environment designs while the LF voltage range allows direct battery connection (two AA cells) without a boost converter.
Technical depth: the silicon uses CMOS Flash technology with self-programmability in the application circuit, eliminating external boot memory. The enhanced 16-bit instruction set supports direct, indirect, relative and indexed addressing, plus a hardware 8x8 multiplier cycle that accelerates 16-bit arithmetic. Three external interrupt sources and a configurable interrupt controller service the timer, capture/compare, ADC, USART and MSSP peripherals.
Typical applications include industrial sensor conditioning, automotive body controllers, building automation nodes, low-power remote controls, consumer appliance user interfaces and battery-backed instrumentation. The 40 MHz throughput with 16 MIPS sustained performance, combined with deep sleep and RTCC wake-up, makes it a strong fit for mains-battery hybrid designs.
A key design consideration: the LF silicon requires the LF configuration bits set correctly; substituting with the non-LF (F-only) variant in the same socket is electrically compatible at 4.5 V to 5.5 V but not below 4.2 V, so always verify the brown-out and voltage-rail spec when designing for two-cell alkaline supplies. Decouple VDD/VSS with 100 nF ceramic placed within 5 mm of the pins to suppress switching transients from the internal charge pump.
This page synthesizes verified distributor pricing, drop-in PIC18-family alternatives and practical design notes not found in the manufacturer datasheet alone, giving engineers a single reference for sourcing, second-sourcing and design-in of the PIC18LF2420-I/SO.
Drop-in alternatives for PIC18LF2420-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 PIC18LF2420-I/SO (same form factor and footprint) — differing in Package, Core Architecture, ADC, Timers, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF2420T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF2420-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF23K22-I/SO
✅ Drop-In✓ In Stock
$1.51 / Unit
View Datasheet →PIC18LF2320-I/SO
✅ Drop-In✓ In Stock
$3.31 / Unit
View Datasheet →PIC18LF2420-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, enhanced) |
| Instruction Set | 16-bit instructions, 8-bit data path |
| Maximum CPU Frequency | 40 MHz |
| Performance | 10 MIPS (4-clock instruction cycle) |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data SRAM | 768 bytes |
| Data EEPROM | 256 bytes |
| Operating Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 25 |
| ADC | 10-bit, up to 13 channels |
| Analog Comparators | 2 |
| USART | 1 (enhanced) |
| MSSP (SPI / I2C) | 1 |
| CCP / ECCP Modules | 2 CCP |
| Timers | Timer0/1/2/3 (16-bit capable) |
| Package | 28-pin SOIC (SO, 7.50 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial, I grade) |
| Technology | CMOS Flash with nanoWatt power management |
| Self-Programming | Yes (Flash program memory) |
| Internal Oscillator | Yes (configurable 31 kHz to 8 MHz via OSCCON) |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC18LF2420-I/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active low |
| Pin 2 | RA0 — Digital I/O / analog AN0 |
| Pin 3 | RA1 — Digital I/O / analog AN1 |
| Pin 4 | RA2 — Digital I/O / analog AN2 / VREF- |
| Pin 5 | RA3 — Digital I/O / analog AN3 / VREF+ |
| Pin 6 | RA4 — Digital I/O (open-drain) / T0CKI |
| Pin 7 | RA5 — Digital I/O / analog AN4 / SS |
| Pin 8 | RE0 — Digital I/O / AN5 (RD only on 40/44-pin parts) |
| Pin 9 | OSC1 — Crystal oscillator input / CLKIN |
| Pin 10 | OSC2 — Crystal oscillator output / CLKOUT |
| Pin 11 | RC0 — Digital I/O / T1OSO / T1CKI |
| Pin 12 | RC1 — Digital I/O / T1OSI / CCP2 |
| Pin 13 | RC2 — Digital I/O / CCP1 |
| Pin 14 | RC3 — Digital I/O / SCL (MSSP) |
| Pin 15 | RC4 — Digital I/O / SDA (MSSP) |
| Pin 16 | RC5 — Digital I/O / SDO (MSSP) |
| Pin 17 | RC6 — Digital I/O / TX (USART) |
| Pin 18 | RC7 — Digital I/O / RX (USART) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 21 | RB0 — Digital I/O / INT0 |
| Pin 22 | RB1 — Digital I/O / INT1 |
| Pin 23 | RB2 — Digital I/O / INT2 |
| Pin 24 | RB3 — Digital I/O / CCP2 alt |
| Pin 25 | RB4 — Digital I/O |
| Pin 26 | RB5 — Digital I/O / PGM |
| Pin 27 | RB6 — Digital I/O / PGC (ICSP clock) |
| Pin 28 | RB7 — Digital I/O / PGD (ICSP data) |
Typical Applications
PIC18LF2420-I/SO is suitable for 6 applications: Battery-Powered Sensor Node, Industrial Control and HMI Front-End, Automotive Body and Accessory Module, Consumer Appliance User Interface, Building Automation Node (HVAC, Lighting), Low-Cost USB / Serial Data Logger.
Battery-Powered Sensor Node
The PIC18LF2420-I/SO fits two-cell alkaline sensor nodes because its 2.0 V to 5.5 V VDD range lets it connect directly to a fresh 3 V battery without a boost regulator. The 10-bit ADC with up to 13 input channels reads temperature, humidity and analog sensor outputs, while nanoWatt sleep modes drop quiescent current to the microampere range for multi-year battery life. Real-world benefit: a 2400 mAh AA pair with 5% duty-cycle sleep wakes can power the node for 5+ years per Microchip nanoWatt characterization. Compared to a 32-bit ARM Cortex-M0+ at the same clock, the PIC18LF2420 spends more time in deep sleep at lower current, and its deterministic single-cycle interrupt response simplifies time-triggered sensor sampling.
Recommended
Industrial Control and HMI Front-End
In factory-automation panels, the PIC18LF2420-I/SO drives LED indicators, scans matrix keypads and serves as a Modbus slave via its USART or MSSP peripherals. The 40 MHz CPU delivers 10 MIPS, enough to debounce key inputs, run a small character LCD interface, and poll slave sensors in a deterministic loop. Its -40 C to +85 C industrial temperature range covers cabinet interior and most outdoor enclosures. The 28-SOIC package is easy to hand-rework during prototyping and is widely accepted by contract assemblers. Real benefit: combining ADC, PWM and serial on one die replaces a discrete MCU + timer + ADC board, shrinking BOM cost by roughly 30% on typical HMI boards.
Recommended
Automotive Body and Accessory Module
For non-safety body modules such as seat controllers, mirror adjusters, interior lighting or aftermarket alarm systems, the PIC18LF2420-I/SO handles PWM motor drive (via two CCP modules), switch debouncing and LIN or USART comms to a central body controller. The 2.0 V to 5.5 V range covers transient-tolerant 12 V vehicle rails after the LDO drop. Although this part is not AEC-Q100 qualified, its industrial temperature grade survives under-dash environments for non-safety accessory use. Benefit: a single chip runs 4 PWM channels plus comms, replacing a discrete motor-driver MCU + discrete logic board.
Recommended
Consumer Appliance User Interface
White-goods appliances like washing machines, dishwashers and microwave ovens use the PIC18LF2420-I/SO to scan capacitive or resistive key panels, drive seven-segment or LCD indicators, and run a simple state machine for the user interface. The 25 I/O pins accept up to 25 individual buttons or a 5x5 matrix, and the two CCP channels can drive buzzer tones or triac-dimmable lamps. Wide VDD range and ESD-robust CMOS inputs tolerate the noisy switched-mode power supply rails common in appliances. Real benefit: deterministic interrupt response keeps the beeper and display in sync with the main control loop without RTOS overhead.
Recommended
Building Automation Node (HVAC, Lighting)
Building automation devices such as BACnet MS/TP thermostats, DALI-2 light controllers and Modbus room sensors benefit from the PIC18LF2420-I/SO's combination of USART, MSSP and PWM on a single 28-pin part. The 2.0 V to 5.5 V range accepts 24 V AC-derived DC rails without a boost stage, and nanoWalt idle keeps idle room-sensor power below 100 uA. Multiple CCP channels enable 0-10 V dimming outputs or DALI bridge control. Benefit: a single chip replaces separate MCU + DAC + relay-driver subsystems, with the LF voltage tolerance simplifying the power-tree design versus non-LF PIC18F2420.
Recommended
Low-Cost USB / Serial Data Logger
Data loggers that read sensors, time-stamp records to internal EEPROM and push results over UART or USB bridge use the PIC18LF2420-I/SO as the recording engine. The 256-byte EEPROM buffers session records, 768 B SRAM handles small ring buffers, and 16 KB Flash stores the application plus a small file system. The 40 MHz performance runs UART-to-EEPROM store-and-forward without overflow at 115200 bps. Real benefit: a single-chip implementation eliminates an external memory chip, and the LF voltage range allows direct 3.6 V Li-SOCl2 primary cell operation for remote, maintenance-free loggers.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF2420-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF2420T-I/SO | PIC18F2420-I/SO | PIC18LF2420-E/SO | PIC18LF23K22-I/SO | PIC18LF2320-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Flash (KB) | 16 | 16 | 16 | 16 | 8 | 8 |
| SRAM (bytes) | 768 | 768 | 768 | 768 | 512 | 512 |
| EEPROM (bytes) | 256 | 256 | 256 | 256 | 256 | 256 |
| Maximum Frequency (MHz) | 40 | 40 | 40 | 40 | 64 | 40 |
| Operating Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.2 V to 5.5 V | 2.0 V to 5.5 V | 1.8 V to 5.5 V | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C |
| Unit Price (1 qty) | $4.20 | $4.20 | $3.90 | $5.40 | $2.80 | $3.60 |
Key Differentiators
- Wide VDD down to 2.0 V for direct battery connection (vs PIC18F2420-I/SO)
- Modernized K-series forward migration path (vs PIC18LF23K22-I/SO)
- Extended temperature option on same die (vs PIC18LF2420-E/SO)
Design Notes
The PIC18LF2420-I/SO wide 2.0 V to 5.5 V VDD range enables direct connection to two-cell alkaline or single-cell Li-primary batteries, but the MCU draws approximately 5 mA to 15 mA at 40 MHz active across this range. For battery-life calculations, use nanoWatt Sleep mode (SCS<1:0> = 00 with Sleep instruction) which drops core current below 1 uA per Microchip DS39698G. Estimated: a 2400 mAh AA pair at 1% duty cycle supports 5+ years of operation assuming 5 mA active and 1 uA sleep. Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin to suppress switching transients.
Route the ICSP/ICD pins (RB6/PGC = pin 27, RB7/PGD = pin 28) directly to an in-circuit programming header with no series resistors, and keep traces under 50 mm for reliable programming at 5 V. The MCLR pin (1) requires a 10 kohm pull-up to VDD; add a 100 nF capacitor from MCLR to ground only if you need hardware reset filtering. Avoid running high-speed digital traces under the SOIC body - keep analog (RAx) traces short and reference them to a clean analog ground if mixing ADC and switching signals on the board.
Do not substitute the PIC18LF2420 with the non-LF PIC18F2420 when designing for sub-4.2 V battery supplies - the F variant has a 4.2 V minimum VDD and will brown-out at 3.3 V. Do not leave the CONFIG fuses at default; the watchdog timer is disabled by default but the brown-out reset voltage and oscillator mode must be set before code download. Per DS39698G, ensure the MCLR pin is not floating during power-up - floating MCLR can cause spurious reset pulses. Use MPLAB X IDE with XC8 compiler for firmware development; older PIC18 assembly code may require header-rename migration for the LF silicon.
Compliance Information
RoHS and lead-free per Microchip product declaration. Not AEC-Q100 qualified for automotive safety; use PIC18LF2420 family V-grade parts for AEC-Q100 in safety-critical applications. REACH compliant per Microchip product statement.
