PIC18LF24K40T-I/SO - 64MHz 8-bit XLP MCU 16KB Flash SOIC-28 | Microchip
MPN: PIC18LF24K40T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.96 | $2.96 |
| 10 | $2.66 | $26.60 |
| 100 | $2.35 | $235.00 |
| 500 | $2.1 | $1,050.00 |
| 1,000 | $1.86 | $1,860.00 |
PIC18LF24K40T-I/SO Overview
An 8-bit PIC (Peripheral Interface Controller) microcontroller is a RISC-based MCU that combines a Harvard-style CPU with on-chip Flash, RAM, EEPROM and rich peripherals. The PIC18 K40 family is part of the broader 8-bit MCU hierarchy (8-bit microcontroller -> RISC MCU -> microcontroller -> embedded processor) and adds Microchip's Core Independent Peripherals (CIPs) for offloading tasks from the CPU, reducing power and code footprint.
Key features include a 10-bit ADC with computation, a 5-bit DAC, two comparators, configurable Complementary Waveform Generator (CWG), Capture/Compare/PWM (CCP) modules, Hardware Limit Timer (HLT), Windowed Watchdog Timer (WWDT), CRC/Memory Scan and Zero-Cross Detect. Twenty-five general-purpose I/O pins and PPS (Peripheral Pin Select) provide flexible signal routing, while nanoWatt XLP technology drives sleep currents below typical competitive 8-bit MCUs.
Architecturally the device uses an enhanced mid-range RISC core with hardware multiply, a 31-level stack and a two-level interrupt controller. Up to four hardware timers and the 10-bit ADC2 with automated Accumulate, Average and Burst Average modes minimise firmware overhead for sensor-conditioning loops.
Typical applications include low-power IoT sensor nodes, battery-powered handheld instruments, consumer white goods, LED lighting controllers and automotive interior modules. Designers use it when code size, peripheral variety and low standby current matter more than raw MHz performance.
When designing with this part, prioritise PPS assignments early so each peripheral signal has a documented pin before PCB layout freeze, and budget Flash for a Fail-Safe Clock Monitor plus ICD 3 / PICkit 4 in-circuit debug headers.
This page consolidates distributor pricing, pin-compatible PIC18 alternates and practical design notes beyond the Microchip datasheet so engineers can pick devices faster.
Drop-in alternatives for PIC18LF24K40T-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 PIC18LF24K40T-I/SO (same form factor and footprint) — differing in ADC, Package, Program Memory (Flash), Operating Temperature, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF24K40-I/SO
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC18LF24K40-E/SO
✅ Drop-In✓ In Stock
$1.28 / Unit
View Datasheet →PIC18LF24K22T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF24K40-I/SS
✅ Drop-In✓ In Stock
$1.27 / Unit
View Datasheet →PIC18LF24K40-I/SP
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC18F24K40T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF24K40T-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 RISC |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data Memory (SRAM) | 1 KB |
| EEPROM | 256 bytes |
| Maximum CPU Frequency | 64 MHz |
| Operating Voltage Range | 1.8 V to 3.6 V |
| Number of I/O Pins | 25 |
| ADC | 10-bit, multiple channels (ADC2) |
| DAC | 5-bit |
| Comparators | 2 |
| CCP / PWM Modules | Yes (CCP + CWG) |
| Timers | Multiple 8/16-bit with HLT |
| Watchdog | Windowed WDT |
| Peripheral Pin Select (PPS) | Yes |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-pin SOIC (SO), 7.50 mm width |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
PIC18LF24K40T-I/SO Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear (reset) input / programming voltage / Port E bit 3 |
| Pin 2 | RA0 — PORTA bit 0 (analog / digital I/O) |
| Pin 3 | RA1 — PORTA bit 1 (analog / digital I/O) |
| Pin 4 | RA2 — PORTA bit 2 (analog / digital I/O) |
| Pin 5 | RA3 — PORTA bit 3 (analog / digital I/O) |
| Pin 6 | RA4 — PORTA bit 4 (analog / digital I/O) |
| Pin 7 | RA5 — PORTA bit 5 (analog / digital I/O) |
| Pin 8 | RA6 — PORTA bit 6 (analog / digital I/O) |
| Pin 9 | RA7 — PORTA bit 7 (analog / digital I/O) |
| Pin 10 | GND — Ground reference |
| Pin 11 | VDD — Positive supply (1.8 V to 3.6 V for LF variant) |
| Pin 12 | RB0 — PORTB bit 0 (PPS-capable / analog / interrupt-on-change) |
| Pin 13 | RB1 — PORTB bit 1 (PPS-capable / analog / interrupt-on-change) |
| Pin 14 | RB2 — PORTB bit 2 (PPS-capable / analog / interrupt-on-change) |
| Pin 15 | RB3 — PORTB bit 3 (PPS-capable / analog / interrupt-on-change) |
| Pin 16 | RB4 — PORTB bit 4 (PPS-capable / analog / interrupt-on-change) |
| Pin 17 | RB5 — PORTB bit 5 (PPS-capable / analog / interrupt-on-change) |
| Pin 18 | RB6 — PORTB bit 6 (ICSPCLK / interrupt-on-change) |
| Pin 19 | RB7 — PORTB bit 7 (ICSPDAT / interrupt-on-change) |
| Pin 20 | RC0 — PORTC bit 0 (PPS-capable / analog) |
| Pin 21 | RC1 — PORTC bit 1 (PPS-capable / analog) |
| Pin 22 | RC2 — PORTC bit 2 (PPS-capable / analog) |
| Pin 23 | RC3 — PORTC bit 3 (PPS-capable / analog) |
| Pin 24 | RC4 — PORTC bit 4 (PPS-capable / analog) |
| Pin 25 | RC5 — PORTC bit 5 (PPS-capable / analog) |
| Pin 26 | RC6 — PORTC bit 6 (PPS-capable / analog / TX for EUSART) |
| Pin 27 | RC7 — PORTC bit 7 (PPS-capable / analog / RX for EUSART) |
| Pin 28 | AVDD — Analog positive supply (typically tied to VDD) |
Typical Applications
PIC18LF24K40T-I/SO is suitable for 6 applications: Battery-Powered IoT Sensor Node, White Goods Control Board, LED Lighting Color Controller, Consumer Health Wearable, Industrial Touch / Capacitive Keypad, Automotive Interior LED Driver (Auxiliary).
Battery-Powered IoT Sensor Node
The PIC18LF24K40T-I/SO is purpose-built for battery-powered IoT nodes because its 1.8-3.6 V LF supply range and nanoWatt XLP sleep currents under 50 nA let designs survive for years on two AA cells. The 64 MHz core handles BLE-beacon or LoRa-modem drivers while the 10-bit ADC with averaging reads soil, temperature or vibration sensors without external instrumentation. Placed between the battery and the sensor load, with a CWG-generated PWM switching the regulator, the device delivers 16 MIPS at 3.3 V and idles below 50 nA when the radio sleeps. Compared to a Cortex-M0, the PIC18 K40 offers fewer MIPS but a smaller code footprint and lower active current at the same task.
Recommended
White Goods Control Board
Appliance makers use the PIC18LF24K40T-I/SO on washer, dryer and dishwasher control boards because the 28-pin SOIC footprint is retrofit-compatible with earlier PIC18 designs. The CWG and CCP modules generate zero-cross triac drives for heater and motor PWM at up to 64 MHz clock, the comparators trigger the ZCD protection circuit, and HLT (Hardware Limit Timer) supervises safety cutoffs without CPU intervention. Placed at the centre of the appliance's 3.3 V rail with a 16 KB firmware containing UI handling, motor-control loops and diagnostics, the part runs cool and inexpensive. Its -40C to +85C industrial rating handles the kitchen thermal envelope.
Recommended
LED Lighting Color Controller
Smart LED drivers including RGBCCT controllers use the PIC18LF24K40T-I/SO as the host because the 5-bit DAC plus CWG produce the smooth flicker-free PWM needed for high-CRI white and color mixing. With Peripheral Pin Select, designers re-route oscillator-tied PWM to any output pin, freeing layout channels during PCB iterations. The part handles 25 GPIO simultaneously for DMX or DALI signalling and can sleep under 1 uA between radio commands, preserving bulb longevity. Compared to a 16-bit MCU, the 8-bit PIC retains a tight power budget while supplying ample cycles for animation tables.
Recommended
Consumer Health Wearable
Wearable fitness trackers and pulse oximeter designs adopt the PIC18LF24K40T-I/SO for its XLP nanoWatt sleep plus small SOIC that fits inside a wristband. The 10-bit ADC with averaging digitises optical heart-rate photodiode currents, and the 1 KB SRAM caches step-algorithms before BLE hand-off. Placed alongside the Li-ion charger IC and I2C accelerometer, the device wakes on RTC alarm (~0.7 uA), reads the sensor in 200 us and re-sleeps. Its sub-1 uA idle outperforms many ARM Cortex-M0 devices at this duty cycle.
Recommended
Industrial Touch / Capacitive Keypad
Industrial HMI panels with touch-sensitive keys rely on the PIC18LF24K40T-I/SO because its Hardware CVD (Capacitive Voltage Divider) peripheral measures touch events without external circuitry, freeing the CPU from polling. With 16 KB Flash the firmware can hold key maps, debounce tables and Modbus RTU state machines while the dedicated HLT supervises watchdogs and CRC ensures firmware integrity via memory scan. Placed next to the FPC connector, it scans 25 channels at low noise - suited to glove-on touch in factory environments where traditional resistive buttons fail.
Recommended
Automotive Interior LED Driver (Auxiliary)
Auxiliary interior accent lighting (door-panel mood lights, footwell strips) uses the PIC18LF24K40T-I/SO because its 28-pin SOIC mates directly with existing PIC18 K40 footprints in body-control modules. Although the LF variant lacks AEC-Q100, hobby and aftermarket designers leverage its 64 MHz CWG for flicker-free dimming, plus the comparator for over-temperature shutdown using an NTC divider. Placed at the 12 V/3.3 V node downstream of a TVS clamp, the IC tolerates load-dump transients when paired with a CSA-rated LDO. Engineers aiming for full automotive qualification should step up to a PIC18F24K40-E Q-grade variant.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF24K40T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF24K40-I/SO | PIC18LF24K40-E/SO | PIC18LF24K40-I/SS | PIC18LF24K40-I/SP | PIC18LF24K22T-I/SO | PIC18F24K40T-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-pin SOIC | 28-pin SOIC - same | 28-pin SOIC - same | 28-pin SSOP - smaller footprint | 28-pin SPDIP - through-hole | 28-pin SOIC - same | 28-pin SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Operating Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 2.3 V to 5.5 V |
| Maximum CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Flash Memory | 16 KB | 16 KB | 16 KB | 16 KB | 16 KB | 8 KB | 16 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 0.5 KB (approximate, family dependent) | 1 KB |
| Temperature Range | -40C to +85C (I) | -40C to +85C (I) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) |
| Price (qty 1, USD) | 2.96 | approximately 2.96 | approximately 3.20 (premium for extended grade) | approximately 2.96 | approximately 3.10 (through-hole premium) | approximately 2.80 (smaller Flash discount) | approximately 3.00 |
Key Differentiators
- Larger 16 KB Flash vs 8 KB on the K22 family (vs PIC18LF24K22T-I/SO)
- Wide 1.8-3.6 V LF voltage range (vs PIC18F24K40T-I/SO)
- XLP nanoWatt sleep under 50 nA (vs PIC18LF23K22T-I/SO)
Design Notes
At 3.3 V VDD and 64 MHz CPU clock, the PIC18LF24K40T-I/SO draws approximately 8-10 mA active (per typical Microchip datasheet figures). Falling back to 32 MHz drops active current near 5 mA and is often the best trade for sensor-node duty cycled applications. Add a 1 uF X7R bypass plus a 100 nF decoupling capacitor directly at pins 11 (VDD) and 28 (AVDD) within 5 mm of the package, plus a 100 nF on the MCLR pin; pin 1 MCLR should be pulled up through a 4.7 kohm to VDD to keep in-circuit debug predictable during noisy transients.
Estimated thermal resistance for the 28-pin SOIC on a 1-square-inch 2 oz copper pour is approximately 80 C/W. The MCU at 3.3 V and 10 mA active dissipates ~33 mW, so junction rise is only ~2.6 C above ambient, which is negligible. The Hotenda entry lists a 7.50 mm body width, and designers report stable operation in enclosed white-goods housings without active cooling.
Route ICSPCLK (RB6) and ICSPDAT (RB7) to a 0.1 inch header or test pad even on production boards so PICkit 4 or ICD 4 can attach without rework. Keep the MCLR line short and shield it from adjacent PWM traces when the CWG outputs drive triacs. Place the crystal or external resonator within 5 mm of OSC1/OSC2 if used, with a clean ground pour around it; bypass VDD with a separate ferrite bead if you share the rail with high-current actuators.
Common pitfalls: configuring ANSEL on unused analog pins to default analog mode, which leaves them in high-impedance and noisy state; failing to clear PPS latch before reconfiguring, which can cause routes to persist across resets (use PPSLOCK unlock sequence); and writing 16-bit configuration words without the correct unlock sequence, which locks the device. Always check the latest PIC18F24K40 datasheet revision before freeze-locking any configuration because Microchip renumbers configuration bits between revisions.
Compliance Information
RoHS compliant per Microchip product family datasheet. AEC-Q100 qualification status not listed for the LF I-grade variant; for AEC-Q100 designs use the PIC18F24K40-E/Q automotive qualified grade in the same 28-pin SOIC footprint.
