PIC18LF24K40-I/SO - 16KB Flash XLP 8-bit MCU | Microchip
MPN: PIC18LF24K40-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.77 | $1.77 |
| 10 | $1.59 | $15.90 |
| 100 | $1.42 | $142.00 |
| 500 | $1.27 | $635.00 |
| 1,000 | $1.12 | $1,120.00 |
| 3,000 | $0.99 | $2,970.00 |
PIC18LF24K40-I/SO Overview
Background: An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, non-volatile program memory, working RAM, and a configurable set of digital and analog peripherals behind a unified register map. PIC18 devices use Microchip's 8-bit modified Harvard architecture with a RISC-like instruction set, 31-level hardware stack, and linear memory model. Within the broader taxonomy, this part sits at MCU -> 8-bit MCU -> PIC18 family -> PIC18 K40 sub-family -> 'LF' (low-voltage, F-variant = Flash). K40-series parts are positioned for cost-sensitive, low-power embedded control where Core Independent Peripherals (CIPs) can offload CPU work.
Key features include 16 KB self-programmable Flash with 8K x 16 organization, 1 KB SRAM, 256 B EEPROM, 25 I/O pins, 4x 10-bit ADC channels (shared with the DAC/comparator), a 5-bit DAC, two comparators with selectable hysteresis, multiple PWM/CCP/CWG channels, Zero-Cross Detect (ZCD), Windowed Watchdog Timer (WWDT), CRC/SCAN memory integrity check, and a Hardware Limit Timer (HLT). XLP delivers sub-uA sleep currents, making the part suitable for battery-powered endpoints that spend most of their life in sleep.
Typical applications include low-power IoT sensor nodes, battery-powered consumer appliances, LED lighting controllers, sensor signal conditioning, white goods and small motor control, and general-purpose 3.3V embedded control in industrial and consumer products. Wide operating voltage (1.8V-3.6V) and rich peripheral set allow the device to replace larger or multi-chip solutions in cost-sensitive designs.
Design consideration: at 3.3V the LF variant supports the full 64 MHz; for higher supply voltages use the PIC18F24K40 variant. Use the CWG, ZCD, and HLT to implement zero-cross TRIAC dimmers or sensor pulse timers without CPU wakeups, preserving XLP sleep current.
This page synthesizes current distributor pricing, pin-compatible drop-in alternatives, and practical design notes not collected in any single manufacturer or distributor datasheet, helping engineers select the right K40 variant for their BOM.
Drop-in alternatives for PIC18LF24K40-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 PIC18LF24K40-I/SO (same form factor and footprint) — differing in ADC, Package, Timers, Operating Temperature, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F24K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF25K40-I/SO
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC18LF24K40-I/SP
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC18LF24K40-I/ML
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC18F25K40-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF24K22-I/SO
✅ Drop-In✓ In Stock
$1.75 / Unit
View Datasheet →PIC18LF24K40-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 8-bit RISC (modified Harvard) |
| Family | PIC18 K40 (XLP, eXtreme Low Power) |
| CPU Clock (max) | 64 MHz |
| Program Flash | 16 KB (8K x 16 words) |
| SRAM | 1 KB |
| EEPROM | 256 B |
| Operating Voltage | 1.8 V to 3.6 V |
| I/O Pins | 25 |
| ADC | 10-bit, multiple channels |
| DAC | 5-bit |
| Comparators | 2 with selectable hysteresis |
| Package | 28-pin SOIC (0.295" / 7.50 mm width) |
| Mounting Type | Surface Mount |
| Temperature Range (I grade) | -40 C to +85 C (industrial) |
| Peripherals (key) | CCP, PWM, CWG, ZCD, WWDT, CRC/SCAN, HLT |
| RoHS Status | Compliant |
PIC18LF24K40-I/SO Pin Configuration
| Pin 1 | RA0 — PORTA bit 0 / AN0 / C1IN0+ / ICSPDAT |
| Pin 2 | RA1 — PORTA bit 1 / AN1 / C1IN0- / C2IN0- / ICSPCLK |
| Pin 3 | RA2 — PORTA bit 2 / AN2 / C1IN1+ / ZCD |
| Pin 4 | RA3 — PORTA bit 3 / AN3 / C1IN1- / MCLR/VPP |
| Pin 5 | RA4 — PORTA bit 4 / AN4 / C1IN3- / T0CKI / SOSCO |
| Pin 6 | RA5 — PORTA bit 5 / AN5 / C2IN1+ / SOSCI |
| Pin 7 | RA6 — PORTA bit 6 / AN6 / C2IN1- |
| Pin 8 | RA7 — PORTA bit 7 / AN7 |
| Pin 9 | RE3 — PORTE bit 3 (input only) / MCLR/VPP alternate |
| Pin 10 | RC0 — PORTC bit 0 / AN8 / C2IN2+ |
| Pin 11 | RC1 — PORTC bit 1 / AN9 / C2IN2- |
| Pin 12 | RC2 — PORTC bit 2 / AN10 / C1IN2+ |
| Pin 13 | RC3 — PORTC bit 3 / AN11 / C1IN2- |
| Pin 14 | RC4 — PORTC bit 4 / AN12 / C2IN3+ |
| Pin 15 | RC5 — PORTC bit 5 / AN13 / C2IN3- |
| Pin 16 | RC6 — PORTC bit 6 / AN14 / TX/CK |
| Pin 17 | RC7 — PORTC bit 7 / AN15 / RX/DT |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply (3.3V nominal, 1.8V-3.6V) |
| Pin 20 | VSS — Ground reference (second pad) |
| Pin 21 | RB0 — PORTB bit 0 / AN12 / INT0 |
| Pin 22 | RB1 — PORTB bit 1 / AN10 / INT1 |
| Pin 23 | RB2 — PORTB bit 2 / AN8 / INT2 |
| Pin 24 | RB3 — PORTB bit 3 / AN9 / INT3 |
| Pin 25 | RB4 — PORTB bit 4 / AN11 |
| Pin 26 | RB5 — PORTB bit 5 / AN13 |
| Pin 27 | RB6 — PORTB bit 6 / ICSPCLK / ICDCLK |
| Pin 28 | RB7 — PORTB bit 7 / ICSPDAT / ICDDATA |
Typical Applications
PIC18LF24K40-I/SO is suitable for 6 applications: Battery-Powered IoT Sensor Node, White Goods and Appliance Control, LED Lighting Controller, Sensor Signal Conditioning Hub, Low-Power Consumer Remote Control, Industrial 3.3V Logic Replacement.
Battery-Powered IoT Sensor Node
The PIC18LF24K40-I/SO is well suited to coin-cell or two-AA IoT sensor nodes thanks to its 1.8V-3.6V wide VDD range and Microchip XLP sub-uA Sleep currents. Its 10-bit ADC and integrated 5-bit DAC handle ratiometric sensor bridges (e.g., load cells, thermistors) without external signal conditioning, while the 16 KB Flash comfortably fits BLE/Sub-GHz stack shims plus application logic. The on-board WWDT, CRC/SCAN, and Hardware Limit Timer let the device wake periodically, verify Flash integrity, and time-bound acquisition windows without loading the CPU. The 25 I/O lines route I2C/SPI sensor buses, a UART console, and interrupt-driven wake sources with margin to spare.
Recommended
White Goods and Appliance Control
The PIC18LF24K40-I/SO drives washing machines, dishwashers, coffee machines, and other small appliances with its Core Independent Peripherals doing most of the work in hardware. The CWG, ZCD, and HLT combination allows a zero-cross TRIAC dimmer or AC half-wave detection without CPU wakeups, while the dual comparators monitor motor current and supply rails. At 3.3V the LF variant is ideal for 2xAA backup batteries that retain settings during mains loss, and the 256 B EEPROM stores user preferences through power cycles. With 25 I/O pins the MCU can drive segment LCDs (via external charge pump), keypads, and triac outputs without expansion chips.
Recommended
LED Lighting Controller
The PIC18LF24K40-I/SO controls constant-current LED drivers with its 16-bit PWM/CCP and complementary waveform generator (CWG) for high-frequency dimming. The 5-bit DAC and two comparators close a constant-current feedback loop around an external MOSFET, while the ZCD pin synchronizes phase control to the AC line for TRIAC-dimmable retrofit lamps. At 1.8V-3.6V the device runs directly from a small switching supply or two-AA cells for portable lighting. The 64 MHz CPU handles DMX-512 or DALI receive in interrupt while the CWG keeps flicker-free PWM at 1 kHz+ resolution. Industrial-grade -40C to +85C operation covers outdoor luminaires.
Recommended
Sensor Signal Conditioning Hub
The PIC18LF24K40-I/SO aggregates analog sensors in industrial process control and HVAC equipment with its 10-bit ADC, dual comparators, and 5-bit DAC. The on-chip op-amp-style analog peripherals eliminate the need for external instrumentation amplifiers on thermocouple, RTD, and 4-20 mA loops, while the SCAN/CRC engine continuously validates Flash integrity for IEC 61508 safety paths. The 1.8V minimum VDD lets the device share a 3.3V sensor rail with redundant ADC reference monitoring. UART/SPI/I2C bridges connect to a host PLC or gateway, and the 16 KB Flash accommodates Modbus RTU or CANopen lighter stacks.
Recommended
Low-Power Consumer Remote Control
The PIC18LF24K40-I/SO is a strong match for handheld remotes and BLE/IR controllers thanks to its sub-uA XLP Sleep current and fast wake-up via the Windowed WWDT or external interrupt. The 25 I/O pins drive a matrix keypad, IR LED (via PWM), and an optional OLED display, while the on-chip comparators detect low-battery on a single cell without an external supervisor. The 1.8V minimum VDD keeps the MCU alive on a single CR2032 coin cell for years, and 256 B EEPROM stores paired device IDs and user preferences. The 64 MHz CPU handles IR protocols (RC5, NEC, SIRC) in interrupt while idle current stays in the uA range.
Recommended
Industrial 3.3V Logic Replacement
The PIC18LF24K40-I/SO is widely deployed as a modernizing replacement for legacy 8-bit microcontrollers in industrial 3.3V controllers, sensor interfaces, and small motor drives. Its wide 1.8V-3.6V range tolerates brownouts on long cable harnesses, while the dual comparators with selectable hysteresis provide robust line-receiver and encoder inputs in noisy factory environments. The 64 MHz CPU and 16 KB Flash cover PID loops, MODBUS framing, and self-test routines; the 256 B EEPROM captures calibration and hour-meter data. Industrial -40C to +85C operation and SOIC-28 assembly-friendly footprint make the part a long-life upgrade for end-of-life discrete-logic boards.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF24K40-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F24K40-I/SO | PIC18LF25K40-I/SO | PIC18LF24K22-I/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-28 | SOIC-28 - same | SOIC-28 - same | SOIC-28 - same |
| Operating Voltage | 1.8V - 3.6V | 2.3V - 5.5V | 1.8V - 3.6V | 1.8V - 3.6V |
| Flash | 16 KB | 16 KB | 32 KB | 8 KB |
| RAM | 1 KB | 1 KB | 2 KB | 512 B |
| EEPROM | 256 B | 256 B | 256 B | 256 B |
| ADC | 10-bit | 10-bit | 10-bit | 10-bit |
| CPU Clock (max) | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Unit Price (1pc, as of 2026-09-28) | ~$1.77 | ~$1.80 (typical catalog) | ~$1.95 (typical catalog) | ~$1.60 (typical catalog) |
Key Differentiators
- Wider low-voltage operating range (1.8V minimum) (vs PIC18F24K40-I/SO)
- Integrated Core Independent Peripherals (CWG, ZCD, HLT, CRC/SCAN) (vs PIC18LF24K22-I/SO)
- Lower unit price in volume production (vs PIC18LF25K40-I/SO)
Design Notes
Decouple both VDD pins (pin 11 and pin 20) of the PIC18LF24K40-I/SO with a 100 nF X7R ceramic cap placed within 5 mm of the package; add a bulk 10 uF tantalum or aluminum polymer cap on the supply rail for transient handling. Place the 100 nF cap closest to the higher-pin-count VDD to minimize parasitic inductance. Failure to decouple both VDD/VSS pairs can cause brownout resets during peak ADC conversion.
Route the ICSPDAT/ICSPCLK traces (RA0/RA1, RB6/RB7) as a short, straight pair with ground on both sides and no adjacent high-frequency signals. Keep the trace length below 50 mm to avoid programming glitches with ICD or PICkit tools. According to Microchip ICD hardware guidelines, add a 4.7 kohm pull-up on MCLR if you rely on in-circuit programming in production test.
Do not apply 5V to any I/O pin on the PIC18LF24K40-I/SO; the LF variant is rated 1.8V-3.6V and absolute-max VDD is 4.0V. If the system rail is 5V, use the PIC18F24K40-I/SO instead. Mixing LF and F pinouts on the same PCB without rail discipline is a common production-line defect; verify VDD before population. Estimated: 3.3V operation with all I/O at VDD is safe; 5V on any pin risks latch-up.
Compliance Information
RoHS and REACH compliance per Microchip product page. Industrial temperature grade -40C to +85C; not AEC-Q100 qualified - choose PIC18F24K40-I/SO or PIC18LF automotive grade variant for automotive applications. Halogen-free per Microchip environmental compliance statement.
