PIC18LF43K22-I/ML - 8KB Flash 8-bit XLP MCU 44-QFN | Microchip
MPN: PIC18LF43K22-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.18 | $31.80 |
| 100 | $2.72 | $272.00 |
| 500 | $2.41 | $1,205.00 |
| 1,000 | $2.13 | $2,130.00 |
PIC18LF43K22-I/ML Overview
What is a PIC XLP microcontroller? An XLP (eXtreme Low Power) MCU is a class of 8-bit microcontroller from Microchip that integrates nanoWatt XLP technology for sub-microamp sleep currents, RTC operation from a 32 kHz crystal, and multiple low-power operating modes (Run, Idle, Sleep, Deep Sleep). It sits within the broader hierarchy: microcontroller -> embedded MCU -> 8-bit MCU -> PIC18 family -> XLP 18K sub-family -> K22 series. The PIC18LF43K22 belongs to the 28/40/44-pin low-power high-performance family described in the manufacturer datasheet.
Key differentiating features include 64 MHz internal oscillator operation, hardware 8x8 multiply, CLC (Configurable Logic Cell) and ECCP (Enhanced Capture/Compare/PWM) peripherals, mTouch capacitive sensing support, 35 I/O pins, and an integrated 12-channel 10-bit ADC. The XLP technology delivers typical sleep currents in the nanoamp range, making this device ideal for applications where quiescent power dominates the energy budget over active compute time.
Architecturally, the PIC18LF43K22 uses an enhanced 8-bit PIC Harvard architecture with separate program and data buses, supporting C-compiler-friendly instruction set extensions. The 8 KB self-programmable Flash, 256 B EEPROM, and 768 B RAM provide ample headroom for state machines, protocol stacks, and sensor fusion in compact sensor nodes.
Typical applications include battery-powered sensor nodes, wearable health monitors, IoT edge devices, consumer remote controls, low-power wireless sensor networks, and e-metering endpoints. The wide Vdd range and robust peripheral mix also suit HMI touch panels and small white-goods user interfaces.
When designing with the PIC18LF43K22, choose the 'LF' variant when Vdd stays at or below 3.6 V (Li coin cells, single-cell Li-Ion, 2xAA). For 5 V rails choose the PIC18F43K22. The 44-QFN exposed pad is mandatory for thermal dissipation; do not leave it floating. The I/ML package suffix indicates industrial temperature range (-40C to +85C) and tube packaging.
This page synthesizes distributor stock status, drop-in alternatives within the same 44-QFN footprint, and practical design notes that extend beyond the datasheet typical application circuits.
Drop-in alternatives for PIC18LF43K22-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 PIC18LF43K22-I/ML (same form factor and footprint) — differing in ADC, Package, MSL Level, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F43K22-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.95 / Unit
View Datasheet →PIC18LF43K22-E/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18LF45K22-I/ML
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F45K22-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.65 / Unit
View Datasheet →PIC18LF26K83-I/ML
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18LF43K22-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit Harvard (enhanced) |
| Family | PIC® XLP™ 18K (K22 series) |
| Program Memory (Flash) | 8 KB (4K x 16 words) |
| Data RAM | 768 B |
| Data EEPROM | 256 B |
| Maximum CPU Speed | 64 MHz (16 MIPS) |
| Operating Voltage (Vdd) | 1.8 V to 3.6 V |
| I/O Pins | 35 |
| ADC | 10-bit, 17 channels |
| Comparators | 2 |
| PWM Outputs | 5 (ECCP + CCP) |
| UART / I2C / SPI | 2 UART, 2 I2C, 2 SPI |
| Timers (8-bit / 16-bit) | 4 / 4 |
| Capacitive Touch (mTouch) | Yes (CTMU + mTouch channels) |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 44-pin QFN (8x8 mm) with exposed pad |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Tube Quantity | 45 per tube (typical for /ML) |
PIC18LF43K22-I/ML Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (analog/digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (analog/digital I/O) |
| Pin 3 | RA4 — Port A bit 4 (analog/digital I/O, TOCKI) |
| Pin 4 | RA5 — Port A bit 5 (analog/digital I/O) |
| Pin 5 | RA6 — Port A bit 6 (oscillator out) |
| Pin 6 | RA7 — Port A bit 7 (oscillator in) |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply (1.8-3.6 V) |
| Pin 9 | MCLR — Master Clear (reset, active low) |
| Pin 10 | RE3 — Port E bit 3 (digital-only input) |
| Pin 11 | RB0 — Port B bit 0 (interrupt-on-change) |
| Pin 12 | RB1 — Port B bit 1 (interrupt-on-change) |
| Pin 13 | RB2 — Port B bit 2 (interrupt-on-change) |
| Pin 14 | RB3 — Port B bit 3 (interrupt-on-change) |
| Pin 15 | RB4 — Port B bit 4 (interrupt-on-change) |
| Pin 16 | RB5 — Port B bit 5 (interrupt-on-change) |
| Pin 17 | RB6 — Port B bit 6 (ICSP programming clock) |
| Pin 18 | RB7 — Port B bit 7 (ICSP programming data) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (1.8-3.6 V) |
| Pin 21 | RC0 — Port C bit 0 (analog/digital I/O) |
| Pin 22 | RC1 — Port C bit 1 (analog/digital I/O) |
| Pin 23 | RC2 — Port C bit 2 (analog/digital I/O, CCP1) |
| Pin 24 | RC3 — Port C bit 3 (analog/digital I/O, SCL1) |
| Pin 25 | RC4 — Port C bit 4 (analog/digital I/O, SDA1) |
| Pin 26 | RC5 — Port C bit 5 (analog/digital I/O) |
| Pin 27 | RC6 — Port C bit 6 (analog/digital I/O, TX1) |
| Pin 28 | RC7 — Port C bit 7 (analog/digital I/O, RX1) |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply (1.8-3.6 V) |
| Pin 31 | RD0 — Port D bit 0 (digital I/O) |
| Pin 32 | RD1 — Port D bit 1 (digital I/O) |
| Pin 33 | RD2 — Port D bit 2 (digital I/O) |
| Pin 34 | RD3 — Port D bit 3 (digital I/O) |
| Pin 35 | RD4 — Port D bit 4 (digital I/O) |
| Pin 36 | RD5 — Port D bit 5 (digital I/O, PWM) |
| Pin 37 | RD6 — Port D bit 6 (digital I/O, CCP4) |
| Pin 38 | RD7 — Port D bit 7 (digital I/O, CCP5) |
| Pin 39 | VSS — Ground reference |
| Pin 40 | VDD — Positive supply (1.8-3.6 V) |
| Pin 41 | RF0 — Port F bit 0 (analog input AN16) |
| Pin 42 | RF1 — Port F bit 1 (analog input AN6) |
| Pin 43 | RF2 — Port F bit 2 (analog input AN7) |
| Pin 44 | RF3 — Port F bit 3 (analog input AN8) |
| Pin 45 | EP — Exposed pad - thermal/ground, must be soldered to PCB |
Typical Applications
PIC18LF43K22-I/ML is suitable for 6 applications: Battery-Powered IoT Sensor Node, Wearable Health Monitor, Consumer Remote Control with Touch Buttons, Industrial Sensor Module (4-20 mA Loop Powered), Smart Home Edge Device, Electronic Metering Endpoints.
Battery-Powered IoT Sensor Node
The PIC18LF43K22-I/ML fits battery-powered IoT sensor nodes because of its nanoWatt XLP technology with sub-microamp sleep currents, 1.8 V minimum Vdd enabling direct 2xAA or coin-cell operation, and 35 I/O pins for multi-sensor multiplexing. With 8 KB Flash and 768 B RAM the MCU comfortably runs Modbus slave or BLE HCI forwarding firmware. The 64 MHz core provides 16 MIPS headroom for periodic sensor preprocessing while sleep-dominant duty cycles keep quiescent draw well under 1 uA, extending multi-year coin-cell life. Recommended companion MPNs: PIC18LF26K83-I/ML (main controller with CAN), MCP9808 (I2C temp sensor), and MCP1700 (LDO).
Recommended
Wearable Health Monitor
For wearable health monitors the PIC18LF43K22-I/ML delivers the low quiescent current needed for continuous heart-rate, SpO2, and skin-temperature sensing while stretching a coin-cell budget. The integrated mTouch capacitive sensing plus CTMU enables solid-state buttons on flexible wearable substrates, and the 10-bit ADC with 17 channels supports direct photodiode amplification for PPG heart-rate sensors. The 44-QFN 8x8 mm package keeps the BOM footprint compact enough for wristband form factors, and the 1.8-3.6 V range aligns with single-cell Li-Ion chemistries. Recommended companions: MCP73831 (Li-Ion charger) and MCP9700 (analog temp sensor).
Recommended
Consumer Remote Control with Touch Buttons
The PIC18LF43K22-I/ML excels in consumer remote controls where mTouch capacitive buttons replace mechanical keys, and ultra-low sleep current preserves battery life across standby months. With 8 KB Flash the MCU can host IR protocol stacks (RC5, NEC, SIRC) plus BLE commissioning logic for set-top boxes. The 5 PWM channels drive IR LEDs at controlled currents while the CTMU measures touch electrode charge times in milliseconds. Operating from 1.8-3.6 V the part runs from 2xAAA without boost converters, eliminating external inductors and shrinking PCB area. Recommended companions: MCP1700 (3.3 V LDO) and TSSP58038 (IR receiver).
Recommended
Industrial Sensor Module (4-20 mA Loop Powered)
For industrial 4-20 mA loop-powered sensor modules the PIC18LF43K22-I/ML is a strong fit because its nanoWatt XLP technology minimizes the current draw budget at the loop floor. The wide 1.8-3.6 V supply range supports the constrained compliance voltage of intrinsically safe (IS) loops, while the 10-bit ADC with 17 channels digitizes multiple bridge or thermocouple sensors simultaneously. The 64 MHz core plus hardware multiplier handles linearization curves and HART protocol framing in real time without taxing the loop current. The 44-QFN EP pad keeps the thermal path short for harsh industrial environments.
Recommended
Smart Home Edge Device
In smart-home edge devices the PIC18LF43K22-I/ML provides the low-power compute foundation for Matter/Zigbee relay nodes, occupancy sensors, and wall switches. The XLP sleep current plus peripheral pin-select remap reduces BOM count by integrating multiple sensor interfaces onto one MCU. Its 35 I/O pins and 5 PWM channels allow direct driving of TRIAC circuits for mains dimmers or relay coils, while the 10-bit ADC reads occupancy, ambient light, and humidity on a single IC. The 64 MHz MIPS throughput handles 1 ms-loop edge control while staying within the LF Vdd ceiling.
Recommended
Electronic Metering Endpoints
The PIC18LF43K22-I/ML is well suited to electronic metering endpoints such as water, gas, and heat meters that demand decade-long battery life and tamper detection. Its nanoWatt XLP sleep modes combined with RTC-from-32 kHz domain allow periodic metrology wake-ups below 1 uA average draw, while the ECCP module generates high-resolution timing for flow pulses and meter calibration. The 17 ADC channels digitize differential pressure sensors, thermistors for heat metering, and battery voltage with one MCU. The 256-byte EEPROM guarantees non-volatile tariff and tamper-log retention across power outages.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF43K22-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F43K22-I/ML | PIC18LF43K22-E/ML | PIC18LF45K22-I/ML | PIC18F45K22-I/ML | PIC18LF26K83-I/ML |
|---|---|---|---|---|---|---|
| Package | 44-QFN (8x8 mm) | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 44-QFN (8x8 mm) - same | 28-QFN (6x6 mm) - DIFFERENT |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Operating Voltage (Vdd max) | 3.6 V | 5.5 V | 3.6 V | 3.6 V | 5.5 V | 5.5 V |
| Flash Memory | 8 KB | 8 KB | 8 KB | 16 KB | 16 KB | 32 KB |
| Data RAM | 768 B | 768 B | 768 B | 1536 B | 1536 B | 2048 B |
| Maximum CPU Speed | 64 MHz (16 MIPS) | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Temperature | -40 C to +85 C (industrial) | -40 C to +85 C | -40 C to +125 C (extended) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| I/O Pins | 35 | 35 | 35 | 35 | 35 | 22 |
| ADC Channels | 17 | 17 | 17 | 17 | 17 | 11 |
Key Differentiators
- Lowest Vdd ceiling in K22 family (3.6 V) (vs PIC18F43K22-I/ML)
- Higher Flash/RAM density within the same 44-QFN (vs PIC18LF45K22-I/ML)
- Industry-standard nanoWatt XLP sleep current (vs PIC18F45K22-I/ML)
Design Notes
Estimated: at 3.0 V Vdd and 64 MHz CPU clock the active current is approximately 8 mA per the K22 family datasheet. In Sleep mode the XLP current drops to roughly 20 nA. For battery designs, budget the duty cycle around the active-to-sleep ratio: every 10 ms wake/sense/sleep cycle at 8 mA active and 20 nA sleep gives an average current of about 4 uA, allowing CR2032 coin cells to last years. Always place a 100 nF decoupling capacitor as close as possible to every Vdd pin, plus a bulk 10 uF near the supply entry.
The 44-QFN exposed pad (EP) is the primary thermal path. Solder the EP to a copper pad of at least 16 mm^2 (4x4 thermal pad) connected to the ground plane with at least 8 thermal vias. Leaving the EP unsoldered increases junction-to-ambient thermal resistance by 30-50%, which can trigger thermal runaway at industrial temperature extremes. Use a stencil aperture of 1:1 to the EP pad with a 0.15 mm release pattern to ensure proper solder wetting.
Route the ICSP pins (RB6/RB7/MCLR/VDD/VSS) as a 2x5 0.1-inch header or surface-mount test pad cluster to enable in-circuit programming and debugging. Keep traces from the 32.768 kHz crystal pins (RA6/RA7 or SOSC pins) short and symmetric, and place a 5-10 pF load capacitor network close to the crystal. The analog AGND and digital DGND should be tied at a single star point under the MCU EP to minimize ADC reference noise in the 10-bit ADC conversions.
Do not exceed 3.6 V on Vdd for the LF variant; the 'F' variant (PIC18F43K22-I/ML) is required for 5 V supplies. Always issue a CLRWDT (clear watchdog) inside main loops longer than 2 seconds to prevent unintended resets during long sleep intervals. Configure the PPS (Peripheral Pin Select) locks to prevent accidental re-mapping after WDT resets. When migrating from LF to F variant, recheck Brown-Out Reset thresholds and ADC voltage reference selection.
Compliance Information
RoHS compliant per DigiKey product listing. Not AEC-Q100 qualified (industrial grade only). Lead-free QFN package, halogen-free per Microchip environmental documentation.
